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  Subjects -> ENVIRONMENTAL STUDIES (Total: 763 journals)
    - ENVIRONMENTAL STUDIES (689 journals)
    - POLLUTION (22 journals)
    - TOXICOLOGY AND ENVIRONMENTAL SAFETY (41 journals)
    - WASTE MANAGEMENT (11 journals)

ENVIRONMENTAL STUDIES (689 journals)            First | 1 2 3 4     

Showing 601 - 378 of 378 Journals sorted alphabetically
Russian Journal of Ecology     Hybrid Journal   (Followers: 1)
S.A.P.I.EN.S     Open Access   (Followers: 2)
Safety Science     Hybrid Journal   (Followers: 28)
San Francisco Estuary and Watershed Science     Open Access   (Followers: 1)
SAR and QSAR in Environmental Research     Hybrid Journal   (Followers: 1)
Saúde e Meio Ambiente : Revista Interdisciplinar     Open Access  
Scandinavian Journal of Work, Environment & Health     Partially Free   (Followers: 12)
Science of The Total Environment     Hybrid Journal   (Followers: 23)
Sciences Eaux & Territoires : la Revue du Cemagref     Open Access  
Scientific Journal of Environmental Sciences     Open Access   (Followers: 1)
Sepsis     Hybrid Journal  
Smart Grid and Renewable Energy     Open Access   (Followers: 9)
Social and Environmental Accountability Journal     Hybrid Journal   (Followers: 2)
Soil and Sediment Contamination: An International Journal     Hybrid Journal   (Followers: 2)
Soil and Tillage Research     Hybrid Journal   (Followers: 6)
SourceOCDE Environnement et developpement durable     Full-text available via subscription   (Followers: 1)
SourceOECD Environment & Sustainable Development     Full-text available via subscription  
South Pacific Journal of Natural and Applied Sciences     Hybrid Journal  
Southern Forests : a Journal of Forest Science     Hybrid Journal   (Followers: 6)
Sriwijaya Journal of Environment     Open Access  
Stochastic Environmental Research and Risk Assessment     Hybrid Journal   (Followers: 4)
Strategic Behavior and the Environment     Full-text available via subscription   (Followers: 2)
Strategic Planning for Energy and the Environment     Hybrid Journal   (Followers: 4)
Studies in Conservation     Hybrid Journal   (Followers: 11)
Studies in Environmental Science     Full-text available via subscription   (Followers: 6)
Sustainability     Open Access   (Followers: 18)
Sustainability in Environment     Open Access   (Followers: 1)
Sustainability of Water Quality and Ecology     Hybrid Journal   (Followers: 3)
Sustainable Cities and Society     Hybrid Journal   (Followers: 24)
Sustainable Development     Hybrid Journal   (Followers: 16)
Sustainable Development Law & Policy     Open Access   (Followers: 6)
Sustainable Development Strategy and Practise     Open Access  
Sustainable Environment Research     Open Access  
Sustainable Technologies, Systems & Policies     Open Access   (Followers: 8)
TECHNE - Journal of Technology for Architecture and Environment     Open Access   (Followers: 7)
Tecnogestión     Open Access  
Territorio della Ricerca su Insediamenti e Ambiente. Rivista internazionale di cultura urbanistica     Open Access  
The Historic Environment : Policy & Practice     Hybrid Journal   (Followers: 5)
The International Journal on Media Management     Hybrid Journal   (Followers: 5)
Theoretical Ecology     Hybrid Journal   (Followers: 8)
Theoretical Ecology Series     Full-text available via subscription   (Followers: 1)
Toxicologic Pathology     Hybrid Journal   (Followers: 16)
Toxicological & Environmental Chemistry     Hybrid Journal   (Followers: 5)
Toxicological Sciences     Hybrid Journal   (Followers: 12)
Toxicology     Hybrid Journal   (Followers: 17)
Toxicology and Applied Pharmacology     Hybrid Journal   (Followers: 17)
Toxicology and Industrial Health     Hybrid Journal   (Followers: 7)
Toxicology in Vitro     Hybrid Journal   (Followers: 12)
Toxicology Letters     Hybrid Journal   (Followers: 12)
Toxicology Mechanisms and Methods     Hybrid Journal   (Followers: 10)
Toxicon     Hybrid Journal   (Followers: 4)
Toxin Reviews     Hybrid Journal   (Followers: 1)
Trace Metals and other Contaminants in the Environment     Full-text available via subscription   (Followers: 2)
Trace Metals in the Environment     Full-text available via subscription   (Followers: 2)
Transportation Research Part D: Transport and Environment     Hybrid Journal   (Followers: 26)
Transylvanian Review of Systematical and Ecological Research     Open Access  
Trends in Ecology & Evolution     Full-text available via subscription   (Followers: 193)
Trends in Environmental Analytical Chemistry     Hybrid Journal   (Followers: 2)
Trends in Pharmacological Sciences     Full-text available via subscription   (Followers: 26)
Tropicultura     Open Access  
UCLA Journal of Environmental Law and Policy     Open Access   (Followers: 5)
UD y la Geomática     Open Access  
Universidad y Ciencia     Open Access   (Followers: 1)
Urban Studies     Hybrid Journal   (Followers: 53)
Veredas do Direito : Direito Ambiental e Desenvolvimento Sustentável     Open Access  
VertigO - la revue électronique en sciences de l’environnement     Open Access   (Followers: 3)
Villanova Environmental Law Journal     Open Access  
Waste Management & Research     Hybrid Journal   (Followers: 9)
Water Environment Research     Full-text available via subscription   (Followers: 41)
Water International     Hybrid Journal   (Followers: 14)
Water, Air, & Soil Pollution     Hybrid Journal   (Followers: 24)
Water, Air, & Soil Pollution : Focus     Hybrid Journal   (Followers: 10)
Waterlines     Full-text available via subscription   (Followers: 2)
Weather and Forecasting     Full-text available via subscription   (Followers: 15)
Weather, Climate, and Society     Full-text available via subscription   (Followers: 11)
Web Ecology     Open Access   (Followers: 6)
Wetlands     Hybrid Journal   (Followers: 25)
Wilderness & Environmental Medicine     Hybrid Journal   (Followers: 3)
Wildlife Australia     Full-text available via subscription   (Followers: 2)
Wiley Interdisciplinary Reviews - Climate Change     Hybrid Journal   (Followers: 18)
Wiley Interdisciplinary Reviews : Energy and Environment     Hybrid Journal   (Followers: 5)
William & Mary Environmental Law and Policy Review     Open Access   (Followers: 2)
World Environment     Open Access   (Followers: 1)
World Journal of Entrepreneurship, Management and Sustainable Development     Hybrid Journal   (Followers: 5)
World Journal of Environmental Engineering     Open Access   (Followers: 2)
World Journal of Environmental Research     Open Access   (Followers: 1)
Worldviews: Global Religions, Culture, and Ecology     Hybrid Journal   (Followers: 8)
Zoology and Ecology     Hybrid Journal   (Followers: 5)
气候与环境研究     Full-text available via subscription   (Followers: 1)

  First | 1 2 3 4     

Journal Cover Journal of Iron and Steel Research, International
  [SJR: 0.661]   [H-I: 22]   [6 followers]  Follow
    
   Full-text available via subscription Subscription journal  (Not entitled to full-text)
   ISSN (Print) 1006-706X
   Published by Elsevier Homepage  [3043 journals]
  • Development trends of environmental protection technologies for Chinese
           steel industry
    • Authors: Hai-feng Wang; Chun-xia Zhang; Jun-mao Qie; Ji-cheng Zhou; Yang Liu; Xiu-ping Li; Fang-qin Shangguan
      Pages: 235 - 242
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Hai-feng Wang, Chun-xia Zhang, Jun-mao Qie, Ji-cheng Zhou, Yang Liu, Xiu-ping Li, Fang-qin Shangguan
      Chinese steel industry has made significant progress on reducing fresh water consumption and CO2/SO2/COD (chemical oxygen demand)/dust emissions, and improving comprehensive utilization of solid waste. Some steel companies have become topped worldwide. However, due to the large output quantity of crude steel, the whole steel industry is still a huge source of pollutants. At present, environmental protection standards are encountering challenges of lack of technical support, taxation policy and other issues. Steel industry is currently facing enormous environmental pressure. The development trends of environmental protection technologies were studied by summarizing different development stages. To realize the development targets, the industry needs to carry out its research with independent intellectual property rights, develop comprehensive management systems and establish ecological chain with other industries. This can not only raise the level of environmental protection in a broader range, but also improve the energy efficiency of iron and steel plants and increase added value of waste utilization. Finally, 23 environmental protection technologies were proposed and 4 new environmental protection practices were studied.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30035-3
       
  • Size analysis of slag eye formed by gas blowing in ladle refining
    • Authors: Ning-ning Lv; Liu-shun Wu; Hai-chuan Wang; Yuan-chi Dong; Chang Su
      Pages: 243 - 250
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Ning-ning Lv, Liu-shun Wu, Hai-chuan Wang, Yuan-chi Dong, Chang Su
      The formation of slag eye in a gas stirred ladle was studied through cold models and industrial trials. In the cold model, water and sodium tungstate solution were employed to simulate liquid steel, and silicon oil was employed to simulate slag. The simulation results revealed that the gas flow rate and bath height had strong effects on the slag eye size. In particular, the thickness of slag layer played a strong role in the slag eye size. In addition, the slag eye could not be formed when the thickness of the top layer was more than 4 cm in water-silicone oil model. Besides, the section area of vessel had a great impact on the slag eye size. Industrial trials results showed a similar trend that the gas flow rate was very significant on the slag eye size. The predictions of the existing models showed larger predictions deviations compared with the experimental data. Moreover, a new model without fitting parameters was developed based on force balance and mathematical derivation, and verified by the experimental data. The new model provides the prediction with small deviations by comparing with the data acquired from cold models and industrial trials.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30036-5
       
  • Mechanism analysis of non-sinusoidal oscillation of continuous casting
           mold synchronously driven by double servomotors
    • Authors: Chao Zhou; Xing-zhong Zhang; Fang Wang; Ping-fei Liu; Yi-ming Fang
      Pages: 251 - 257
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Chao Zhou, Xing-zhong Zhang, Fang Wang, Ping-fei Liu, Yi-ming Fang
      Due to the disadvantages of complexity, high maintenance and vast investment of the electro-hydraulic servo oscillator, a new mechanical device synchronously driven by double servomotors was proposed. The working principle of the non-sinusoidal oscillator was analyzed and the model of the oscillator was validated via simulation software. Then, taking advantage of resonance technology, the hinging force and moment were calculated. The results showed that the hinging force and driving moment reduced, which was useful in reducing the impact of the hinge and prolonging the service life of the bearing. Besides, the best initial spring pressure was 0.9 times the mold gravity, which improved the oscillation system stability and reduced the load fluctuation and servomotor driving power.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30037-7
       
  • Effect of Al2O3 modification on enrichment and stabilization of chromium
           in stainless steel slag
    • Authors: Long-hu Cao; Cheng-jun Liu; Qing Zhao; Mao-fa Jiang
      Pages: 258 - 265
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Long-hu Cao, Cheng-jun Liu, Qing Zhao, Mao-fa Jiang
      Spinel phase is considered to be the optimal phase for stabilization of chromium in stainless steel slag. In order to restrain chromium leaching from slag for the effective environmental protection, Al2O3 was utilized for the modification treatment, and the effects on the enrichment and stabilization of chromium were investigated. The mineral phases and the existence state of chromium in slag with various Al2O3 contents at different basicities (w CaO/w SiO2) were analyzed by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and X-ray diffraction (XRD). The results showed that chromium mainly existed in the glass and spinel phases at basicity of 1.0 and 1.5. As the slag basicity increased to 2.0, chromium was also found in periclase phase. Al2O3 in the stainless steel slag reacted with MgO and Cr2O3, which could generate the Al-rich Mg(Cr x Al1–x )2O4 solid solution. Moreover, the addition of Al2O3 was favorable to reduce the solubility of chromium oxide in liquid phase and suppress the precipitation of periclase phase. The experimental results demonstrated that Al2O3 modification has a positive influence on the enrichment and the stabilization of chromium in the stainless steel slag.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30038-9
       
  • Effects of high pressure roller grinding on size distribution of
           vanadium-titanium magnetite concentrate particles and improvement of green
           pellet strength
    • Authors: Feng Chen; Yu-feng Guo; Tao Jiang; Fu-qiang Zheng; Shuai Wang; Ling-zhi Yang
      Pages: 266 - 272
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Feng Chen, Yu-feng Guo, Tao Jiang, Fu-qiang Zheng, Shuai Wang, Ling-zhi Yang
      The vanadium-titanium magnetite concentrate from Panxi region of China was pretreated by high pressure roller grinding (HPRG) and then used in pelletization. Size distribution change of the vanadium-titanium magnetite concentrate after HPRG and the improvement of its green pellet strength were investigated. The results indicated that, besides the increase of fine particles, the vanadium-titanium magnetite concentrate after HPRG had a smaller size ratio of fine particle to coarse particle of 0.126, meaning a lower porosity, compared with the size ratio of raw material of 0.157. The concentrate particles were more closely packed when there was a smaller size ratio of fine particle to coarse particle. The particle packing in the green pellets was closer after HPRG, which strengthened the green pellets with an average drop number of 5.1 (drop height of 0.5 m) and average compressive strength of 13.1 N per pellet of 11 mm in diameter.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30039-0
       
  • Effects of process parameters on surface quality, composition segregation,
           microstructure and properties of QSn6. 5-0. 1 alloy slabs fabricated by
           HCCM horizontal continuous casting
    • Authors: Yang Liu; Xin-hua Liu; Hua-dong Fu; Min-xuan Lou; Jian-xin Xie
      Pages: 273 - 281
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Yang Liu, Xin-hua Liu, Hua-dong Fu, Min-xuan Lou, Jian-xin Xie
      Columnar-grained QSn6. 5-0. 1 alloy slabs with a width of 70 mm and thickness of 10 mm were fabricated by heating-cooling combined mold (HCCM) horizontal continuous casting. The effects of process parameters on solidification microstructure, surface quality, composition segregation and mechanical properties were studied. The results showed that the slabs with good surface quality, excellent mechanical properties and no obvious segregation could be prepared at the melt casting temperature of 1250 °C, the heating-mold temperature of 1150—1200 °C, the cooling water flow rate of 600 L/h and the casting speed of 20—80 mm/min. The slabs had the yield strength of 124—155 MPa, the elongation rate of 46.6%—56.3% and the surface roughness of 0.22—0.55 μm, which enabled them to be directly processed without subsequent milling surface. The ratio of Sn content in the surface to that in the core was 0.83—1.10, with an average value close to 1.0, and not obviously influenced by process parameters. When the casting speed increased from 20 to 80 mm/min, the grain size changed little if the other process parameters were the same. When the heating-mold temperature increased from 1150 to 1200 °C, the grain size was obviously refined and became more uniform if the casting speed was the same. Within the range of the casting speed at which the columnar grain structure could be obtained, the columnar grain size was mainly influenced by the heating-mold temperature.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30040-7
       
  • Stress corrosion cracking behavior of PH13-8Mo stainless steel in
           Cl– solutions
    • Authors: Qiang Yu; Chao-fang Dong; Jian-xiong Liang; Zhen-bao Liu; Kui Xiao; Xiao-gang Li
      Pages: 282 - 289
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Qiang Yu, Chao-fang Dong, Jian-xiong Liang, Zhen-bao Liu, Kui Xiao, Xiao-gang Li
      The stress corrosion cracking (SCC) behavior of PH13-8Mo precipitation hardening stainless steel (PHSS) in neutral NaCl solutions was investigated through slow-strain-rate tensile (SSRT) test at various applied potentials. Fracture morphology, elongation ratio, and percentage reduction of area were measured to evaluate the SCC susceptibility. A critical concentration of 1.0 mol/L neutral NaCl existed for SCC of PH13-8Mo steel. Significant SCC emerged when the applied potential was more negative than —0.15 VSCE, and the SCC behavior was controlled by an anodic dissolution (AD) process. When the applied potential was lower than —0.55 VSCE, an obvious hydrogen-fracture morphology was observed, which indicated that the SCC behavior was controlled by hydrogen-induced cracking (HIC). Between —0.15 and —0.35 VSCE, the applied potential exceeded the equilibrium hydrogen evolution potential in neutral NaCl solutions and the crack tips were of electrochemical origin in the anodic region; thus, the SCC process was dominated by the AD mechanism.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30041-9
       
  • Effects of Mn and Cr contents on microstructures and mechanical properties
           of low temperature bainitic steel
    • Authors: Hui Guo; Peng Zhou; Ai-min Zhao; Chao Zhi; Ran Ding; Jia-xing Wang
      Pages: 290 - 295
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Hui Guo, Peng Zhou, Ai-min Zhao, Chao Zhi, Ran Ding, Jia-xing Wang
      The effects of Mn and Cr contents on bainitic transformation kinetics, microstructures and mechanical properties of high-carbon low alloy steels after austempered at 230, 300 and 350 °C were determined by dilatometry, optical microscopy, scanning electron microscopy, X-ray diffraction and tensile tests. The results showed that Mn and Cr can extend bainitic incubation period and completion time, and with the increase of Mn and Cr content, the bainitic ferrite plate thickness decreased and the volume fraction of retained austenite increased. TRIP (transformation induced plasticity) effect was observed during tensile testing which improved the overall mechanical property. The increase of Mn concentration can improve the strength to a certain extent, but reduce the ductility. The increase of Cr concentration can improve the ductility of bainitic steels which transformed at a low temperature. The low temperature bainitic steel austempered at 230 °C exhibited excellent mechanical properties with ultimate tensile strength of (2146 ± 11) MPa and total elongation of (12.95 ± 0.15) %.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30042-0
       
  • Structures and electrochemical performances of as-cast and spun
           RE-Mg-Ni-Mn-based alloys applied to Ni-MH battery
    • Authors: Yang-huan Zhang; Zhong-hui Hou; Ying Cai; Hong-wei Shang; Yan Qi; Dong-liang Zhao
      Pages: 296 - 305
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Yang-huan Zhang, Zhong-hui Hou, Ying Cai, Hong-wei Shang, Yan Qi, Dong-liang Zhao
      The RE-Mg-Ni-Mn-based AB2-type La1–x Ce x MgNi3.5 Mn0.5 (x = 0–0.4) alloys were prepared by spinning treatment. For obtaining the optimum performance, the effects of Ce content and spinning rate on the hydrogen storage performance of the alloys were studied systematically. The results show that the variations of the spinning rate and Ce content result in noteworthy changes of the phase content without altering phase composition of the alloys. Specifically, the LaMgNi4 phase increases and LaNi5 phase decreases when increasing the spinning rate and Ce content. Furthermore, the crystalline grains of Ce-containing alloys prepared by spinning treatment are remarkably refined. The alloys own superior electrochemical performance. All alloys reach the optimal discharge capacity at the initial cycle. Increasing Ce content and spinning rate lead the discharge capacity and electrochemical kinetics rise to an optimal value and then start to reduce. Meanwhile, the electrochemical cycle stability is also improved, which is ascribed to the great enhancement of anti-pulverization and anti-corrosion abilities resulting from the spinning treatment and the substitution of Ce for La.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30043-2
       
  • In-flight particle characterization and coating formation under low
           pressure plasma spray condition
    • Authors: Nan-nan Zhang; Dan-yang Lin; Ya-li Li; Yue Zhang; Marie-pierre Planche; Han-lin Liao; Christian Coddet; Fu-yu Dong
      Pages: 306 - 312
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Nan-nan Zhang, Dan-yang Lin, Ya-li Li, Yue Zhang, Marie-pierre Planche, Han-lin Liao, Christian Coddet, Fu-yu Dong
      Yttria-stabilized zirconia (YSZ) coatings were deposited by low pressure plasma spray (LPPS) in 1.0 × 104 Pa, 1.5 × 104 Pa, and 2.5 × 104 Pa. Both in-flight particle diagnostic detected by DPV-2000 system and ANSYS-FLUENT software were used to study the connection between the parameters of flying particles and the coating formation, which might help to recognize the relationship between the operation parameters and the coatings quality. The results of simulation showed that particles in a lower spray pressure could achieve a higher velocity. The particle velocity was around 380 m/s at a distance of 35 cm from the nozzle at 1.0 × 104 Pa while only 300 m/s at 2.5 × 101 Pa in actual measurement. The results showed that the velocity of particles increased with decreasing the spray pressure, which might enhance the flattening rate of coatings and thereby decreased the porosity. The deposited YSZ coating with the lowest porosity can be gained under 1.0 × 104 Pa condition.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30044-4
       
  • In-situ analysis of retained austenite transformation in high-performance
           micro-alloyed TRIP steel
    • Authors: Ji-bo Peng; Hu Jiang; Gong-ting Zhang; Li-ben Chen; Na-qiong Zhu; Yan-lin He; Xiao-gang Lu; Lin Li
      Pages: 313 - 320
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Ji-bo Peng, Hu Jiang, Gong-ting Zhang, Li-ben Chen, Na-qiong Zhu, Yan-lin He, Xiao-gang Lu, Lin Li
      Microstructures and mechanical properties of Ti-V micro-alloyed TRIP (transformation-induced plasticity) steel with different compositions were investigated by tensile test, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermodynamic calculation (TC). The results indicated that the steel exhibited high ultimate tensile strength (1079 MPa), sufficient ductility (28%) and the highest product of strength and ductility (30212 MPa · %) heat treated after intercritical annealing at 800 °C for 3 min and bainitic annealing at 430 °C for 5 min. In addition, the change of volume fraction of retained austenite (VF-RA) versus tensile strain was measured using in-situ analysis by X-ray stress apparatus and micro-electronic universal testing machine. It was concluded that a-value could be used to evaluate the stability of retained austenite (S-RA) in the investigated Ti-V micro-alloyed TRIP steel. The smaller a-value indicated the higher stability of retained austenite (S-RA) and the higher mechanical properties of Ti-V micro-alloyed TRIP steel.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30045-6
       
  • Prediction of mechanical behavior of ferrite-pearlite steel
    • Authors: Lei Wang; Di Tang; Yong Song
      Pages: 321 - 327
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Lei Wang, Di Tang, Yong Song
      A new approach describing the flow stress of ferrite-pearlite steel has been proposed, which divided the deformation process into three stages based on whether ferrite or pearlite yielded. Iso-work increment assumption was applied to describe the transfer of load between the components. The physically based model to describe ferrite was approximated with Swift's equation in order to obtain the analytic solution. The tensile strength of ferrite-pearlite had a linear relation with pearlite volume fraction, square root reciprocal of ferrite grain size and reciprocal of pearlite interlamellar spacing. Moreover, a model to calculate the tensile strength of ferrite-pearlite steel was proposed. The predicted values of tensile strength were in good agreement with experimental results when the pearlite volume fraction was less than 20%. Considering the plastic relaxation mechanisms, the internal stress was modified with pearlite volume fraction, total strain, yield stress of ferrite and pearlite when the pearlite volume fraction was more than 20%.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30046-8
       
  • Effects of alloying elements X (X=Zr, V, Cr, Mn, Mo, W, Nb, Y) on
           ferrite/TiC heterogeneous nucleation interface: first-principles study
    • Authors: Hui-hui Xiong; Heng-hua Zhang; Hui-ning Zhang; Yang Zhou
      Pages: 328 - 334
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Hui-hui Xiong, Heng-hua Zhang, Hui-ning Zhang, Yang Zhou
      The segregation behavior of alloying elements X (X=Zr, V, Cr, Mn, Mo, W, Nb, Y) on the ferrite (100)/TiC(100) interface has been investigated using first principles method, and the work of separation and interface energy of ferrite/TiC interfaces alloyed by these elements were also analyzed. The results indicated that all these alloying additives except Y were thermodynamically favorable because of the negative segregation energy, showing that they have the tendency to segregate to the ferrite/TiC interface. When the Fe atom in the ferrite/TiC interface is replaced by Y, Zr, or Nb, the adhesive strength of the interface will be weakened due to the lower separation work, larger interfacial energy, and weaker electron effects. However, the introduction of Cr, Mo, W, Mn and V will improve the stability of the ferrite/TiC interface through strong interaction between these elements and C, and Cr-doped interface is the most stable structure. Therefore, the Cr, Mo, W, Mn and V in ferrite side of the interface can effectively promote ferrite heterogeneous nucleation on TiC surface to form fine ferrite grain.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30047-x
       
  • Effect of hot/warm roll-forming process on microstructural evolution and
           
    • Authors: Xue-feng Peng; Jing Liu; Jing-tao Han; Dong-bin Wei
      Pages: 335 - 342
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Xue-feng Peng, Jing Liu, Jing-tao Han, Dong-bin Wei
      To improve the strength-toughness of traditional U-rib (TUR) and solve the problem of insufficient penetration between TUR and deckplate, a new local thickened U-rib (LTUR) has been proposed to improve the fatigue resistance of the weld joint under the premise of not increasing thickness and strength of the TUR material. And a hot/warm roll-forming process (RFP) adopting partially induction heating to 700—1000 °C was carried out to fabricate LTUR. The deformation behaviors in the forming process and microstructure of LTUR have been investigated. Mechanical properties and fracture mechanism of the LTUR after hot/warm RFP have been systematically discussed. Moreover, the results are compared with those obtained in cold RFP. Mechanical properties of the LTUR deformed above the critical transformation temperature (A c3) show high performance characteristics with marked fatigue resistance and superior toughness. Upon increasing the heating temperature from 700 to 900 °C, the initial coarse ferrite-pearlite structure transform into equiaxed ultrafine ferrite (1—3 μm) and precipitates such as (Nb, Ti)(C, N) are uniformly distributed in the matrix. The average dislocation density of the specimens after hot roll-forming at heating temperature of 900 °C decreases dramatically compared with those of the specimens subjected to the cold RFP. Furthermore, a typical characteristic of ductile fracture mechanism and the high impact energy are more convinced that the specimens deformed above 900 °C have obtained an optimal combination of strength and toughness.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30048-1
       
  • High temperature oxidation resistance of CrN/(Ti, Al, Zr, Cr)N bilayer
           films deposited by multi-arc ion plating
    • Authors: Shi-lu Zhao; Zhen Zhang; Jun Zhang; Jian-ming Wang; Zheng-gui Zhang; Shuang-hong Wang
      Pages: 343 - 349
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Shi-lu Zhao, Zhen Zhang, Jun Zhang, Jian-ming Wang, Zheng-gui Zhang, Shuang-hong Wang
      CrN/(Ti, Al, Zr, Cr) N bilayer films were successfully deposited on cemented carbide (WC-8%Co) substrates by multi-arc ion plating process using two Ti-Al-Zr alloy targets and one pure Cr target. As a result of bilayered structure and addition of alloying elements (e. g. Al and Cr), the films exhibited excellent high temperature oxidation resistance under both short-term isothermal (up to 800 °C) and long-term cyclic (up to 600 °C) exposure conditions. Combined with pre-established outstanding tribological properties (e. g. maximum hardness of 4000 HV0.01 and maximum adhesion strength over 200 N), these observations make such films quite a promising candidate to extend the cutting tool life span and boost the performance in high-productivity, high-speed and high-feed cutting or in dry machining conditions.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30049-3
       
  • Microstructure failure in ferrite-martensite dual phase steel under
           in-situ tensile test
    • Authors: Rui-bin Gou; Wen-jiao Dan; Wei-gang Zhang; Min Yu; Chun-yu Zhang; Yin-hu Qiao; Lu Ma
      Pages: 350 - 356
      Abstract: Publication date: March 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 3
      Author(s): Rui-bin Gou, Wen-jiao Dan, Wei-gang Zhang, Min Yu, Chun-yu Zhang, Yin-hu Qiao, Lu Ma
      To investigate microstructure failure in ferrite-martensite dual phase steel, in-situ observations were performed on multiple plate DP800 specimens during uniaxial tensile tests. Microstructure evolution of the observed region was investigated in details. The experimental data showed that micro-cracks in various regions differed in the initiation time, and micro-failures mainly occurred from the locations with typical characteristics of stress concentration (i. e. ferrite interiors, the interfaces of ferrite-martensite grains and the martensite-martensite interfaces). Growth of micro-crack generally experienced the following stages: cracking from martensite boundaries, tiny particles in ferrite interiors, or martensite interiors, propagating in ferrite, bypassing martensite boundaries, or passing through martensite-martensite interfaces, finally ending on martensite boundaries. Martensite was one important source of micro-failure and changed the propagation of micro-cracks significantly. Microstructure deformation was inhomogeneous in the stage of plastic deformation.

      PubDate: 2017-03-25T10:37:40Z
      DOI: 10.1016/s1006-706x(17)30050-x
       
  • Development of Chinese duplex stainless steel in recent years
    • Authors: Zhi-gang Song; Han Feng; Shao-mei Hu
      Pages: 121 - 130
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Zhi-gang Song, Han Feng, Shao-mei Hu
      The development in research, production, applications, and national standards of Chinese duplex stainless steel (DSS) in recent years was introduced in light of the worldwide development in the field of DSS. The results showed that the output of Chinese DSS increased greatly, and at the same time its grade gradually evolved into a collaborative developing series including the main grade type 2205 and other DSS types in recent years. Economical DSS and super DSS underwent rapid development, especially after 2010. In recent years, the application of Chinese DSS has been expanded further not only in traditional application areas such as the petrochemical industry, but also in diverse new fields such as oil and gas transportation, chemical tanker manufacturing, nuclear power plants, and construction. Moreover, due to the increase in output and improvement in quality, as well as applications in Chinese projects, Chinese DSS has also been exported to the Middle East, Eastern Europe, and other regions.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30018-3
       
  • Recovery of boron from high-boron iron concentrate using reduction
           roasting and magnetic separation
    • Authors: Jian-wen Yu; Yue-xin Han; Peng Gao; Yan-jun Li
      Pages: 131 - 137
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Jian-wen Yu, Yue-xin Han, Peng Gao, Yan-jun Li
      The comprehensive utilization of abundant high-boron iron concentrate is of particular significance to China, and the high-boron iron concentrate has not yet been utilized as a source for boron at an industrial scale due to its complex mineralogy and fine mineral dissemination. An innovative method was proposed for recovery of boron and iron from high-boron iron concentrate by reduction roasting and magnetic separation. The effects of reduction temperature and roasting time were investigated and their optimum conditions were determined. The mineralogical changes during roasting were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the pyrrhotite (FeS) contained in the high-boron iron concentrate and the new-formed FeS-Fe solid solution softened or melted at high temperatures owing to their low melting points, and then decreased the metallic iron ratio and accelerated the growth of metallic iron particles. Meanwhile, the magnetite and szaibelyite were converted into metallic iron and suanite, respectively. Consequently, boron was readily enriched into the non-magnetic product and the metallic iron was aggregated to the magnetic concentrate by magnetic separation. Boron recovery of 88. 6% with corresponding B2 O3 content of 14. 5% and iron recovery of 95. 1% with an iron grade of 92. 7% were achieved when high-boron iron concentrate was reduced at 1125 °C for 150 min. Besides, the boron reactivity of the boron-rich non-magnetic product was up to 80. 8%.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30019-5
       
  • Characteristics of metal flow in cold extrusion under electric-hydraulic
           chattering
    • Authors: Zhi-heng Wang; Wei-tao Zhan; Xiao-xiao Hong; Guan-jun Bao; Qing-hua Yang
      Pages: 138 - 146
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Zhi-heng Wang, Wei-tao Zhan, Xiao-xiao Hong, Guan-jun Bao, Qing-hua Yang
      An experimental setup for cold extrusion process with electric-hydraulic chattering was developed and its working principle was introduced. The finite element (FE) model for a kind of cup part (material: 20Cr) was built by using the software Deform-3D. FE simulation experiments with and without electric-hydraulic chattering were carried out to analyze the velocity fields and the metal grid flow lines. The extrusion experiments of the cup part were also performed under different conditions. The difference of metal flow lines with and without electric-hydraulic chattering was discussed via a scanning electron microscope (SEM) and the Keyence super-depth three-dimensional microscopic system. The results showed that with the electric-hydraulic chattering, the velocity of material flow increases, whereas deformation resistance decreases. Electric-hydraulic chattering results in easy metal flow, small bending degree of metal flow lines, slender and dense metal grains, and thereby an improved quality of the deformed parts.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30020-1
       
  • Iron recovery and rare earths enrichment from Bayan Obo tailings using
           Coal-Ca(OH)2-NaOH roasting followed by magnetic separation
    • Authors: Qiang Zheng; Xue Bian; Wen-yuan Wu
      Pages: 147 - 155
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Qiang Zheng, Xue Bian, Wen-yuan Wu
      The recovery of iron and enrichment of rare earths from Bayan Obo tailings were investigated using Coal-Ca(OH)2-NaOH roasting followed by magnetic separation. The influences of roasting temperature, roasting time, coal content, milling time, Ca(OH)2 dosage and NaOH dosage on the iron and rare earths recovery were explored. The results showed that the magnetic concentrate containing 70. 01 wt. % Fe with the iron recovery of 94. 34% and the tailings of magnetic separation containing 11. 46 wt. % rare earth oxides (REO) with the REO recovery of 98. 19% were obtained under the optimum conditions (i. e., roasting temperature of 650 °C, roasting time of 60 min, coal content of 2. 0%, milling time of 5 min, and NaOH dosage of 2. 0%). The Ca(OH)2 dosage had no effect on the separation of iron and rare earths. According to the mineralogical and morphologic analysis, the iron and rare earths of Bayan Obo tailings could be utilized in subsequent ironmaking process and hydrometallurgy process.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30021-3
       
  • Effects of embedding direct reduction followed by magnetic separation on
           recovering titanium and iron of beach titanomagnetite concentrate
    • Authors: Chao Geng; Ti-chang Sun; You-wen Ma; Cheng-yan Xu; Hui-fen Yang
      Pages: 156 - 164
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Chao Geng, Ti-chang Sun, You-wen Ma, Cheng-yan Xu, Hui-fen Yang
      Embedding direct reduction followed by magnetic separation was conducted to fully recover iron and titanium separately from beach titanomagnetite (TTM). The influences of reduction conditions, such as molar ratio of C to Fe, reduction time, and reduction temperature, were studied. The results showed that the TTM concentrate was reduced to iron and iron-titanium oxides, depending on the reduction time, and the reduction sequence at 1200 °C was suggested as follows; Fe2. 75 Ti0. 25 O4→Fe2 TiO4→FeTiO3→FeTi2 O5. The reduction temperature played a considerable role in the reduction of TTM concentrates. Increasing temperature from 1100 to 1200 °C was beneficial to recovering titanium and iron, whereas the results deteriorated as temperature increased further. The results of X-ray diffraction and scanning electron microscopy analyses showed that low temperature (≤ 100 °C) was unfavorable for the gasification of reductant, resulting in insufficient reducing atmosphere in the reduction process. The molten phase was formed at high temperatures of 1250–1300 °C, which accelerated the migration rate of metallic particles and suppressed the diffusion of reduction gas, resulting in poor reduction. The optimum conditions for reducing TTM concentrate are as follows: molar ratio of C to Fe of 1. 68, reduction time of 150 min, and reduction temperature of 1200 C. Under these conditions, direct reduction iron powder, assaying 90. 28 mass% TFe and 1. 73 mass% TiO2 with iron recovery of 90. 85%, and titanium concentrate, assaying 46. 24 mass% TiO2 with TiO2 recovery of 91. 15%, were obtained.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30022-5
       
  • Optimization of magnetic separation process for iron recovery from steel
           slag
    • Authors: Yuan-pei Lan; Qing-cai Liu; Fei Meng; De-liang Niu; Heng Zhao
      Pages: 165 - 170
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Yuan-pei Lan, Qing-cai Liu, Fei Meng, De-liang Niu, Heng Zhao
      To improve the efficiency of iron recovery from steel slag and reduce the wear-and-tear on facilities, a new method was proposed by adding a secondary screen sizer to the magnetic separation process according to grain size distribution of magnetic iron (M-Fe) in the slag. The final recycling efficiency was evaluated by calculating the percentage of recycled M-Fe to the maximum amount of M-Fe that could be recovered. Three types of slags, namely basic oxygen furnace slag, desulfurization slag, and iron ladle slag, were studied, and the results showed that the optimized recovery efficiencies were 93. 20%, 92. 48%, and 85. 82% respectively, and the recycling efficiencies were improved by 9. 58%, 7. 11%, and 6. 21% respectively. Furthermore, the abrasion between the mill equipment and the remaining slags was significantly reduced owing to the efficient recovery of larger M-Fe particles. In addition, the using amount of grinding balls was reduced by 0. 46 kg when every 1 t steel slag was processed.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30023-7
       
  • Phase-field simulation of tip splitting in dendritic growth of Fe-C alloy
    • Authors: Yong-sheng Kang; Yu-chun Jin; Yu-hong Zhao; Hua Hou; Li-wen Chen
      Pages: 171 - 176
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Yong-sheng Kang, Yu-chun Jin, Yu-hong Zhao, Hua Hou, Li-wen Chen
      Two types of dendrite tip splitting including dendrite orientation transition and twinned-like dendrites in Fe-C alloys were investigated by phase-field method. In equiaxed growth, the possible dendrite growth directions and the effect of supersaturation on tip splitting were discussed; the dendrite orientation transition was observed, and it was found that the orientation regions of anisotropy parameters were reduced from three to two with increasing the supersaturation, which was due to the effect of interfacial anisotropy controlled by the solute in front of S/L interface changing with the increase of supersaturation. In directional solidification, it was found that the twinned-like dendrites were formed with the fixed anisotropy couples and no seaweed dendrites were observed; these were concluded from the results of competition between process anisotropy and inherent anisotropy. The formation process of twinned-like dendrite was investigated by tip splitting phenomenon, which was related to the changes of dendrite tips growth velocity. Then, the critical speed of tips splitting and solute concentration of twinned-like dendrites were investigated, and a new type of microsegregation in Fe-C alloys was proposed to supplement the dendrite growth theories.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30024-9
       
  • Effects of Ni on austenite stability and fracture toughness in high Co-Ni
           secondary hardening steel
    • Authors: Chen-chong Wang; Chi Zhang; Zhi-gang Yang
      Pages: 177 - 183
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Chen-chong Wang, Chi Zhang, Zhi-gang Yang
      Three kinds of high Co-Ni secondary hardening steels with different Ni contents were studied. The nanoscale austenite layers formed at the interface of matensite laths were observed. Both observation and diffusion kinetic simulation results showed that both Ni and Co did not obtain enough time to get the equilibrium content in this system. The Ni content in austenite layers decreased significantly, and Co content increased slightly with the decrease of Ni content in overall composition. The austenite stability was estimated by Olson-Cohen model, in which both chemical and mechanical driving force could be calculated by equilibrium thermodynamic and Mohr's circle methods, respectively. Simulation and mechanical test results showed that the decrease of Ni content in austenite layers would cause the change of austenite stability and decrease the fracture toughness of the steels. When the Ni content in the overall composition was lower than 7 wt. %, the Ni content in y phase would be lower than 20 wt. %. And the simulation value of M s σ (stress-induced critical martensite transformation temperature) would be up to 80 °C, which was about 60 °C higher than room temperature. Based on the analysis, the Ni content in the overall composition of high Co-Ni secondary hardening steels should be higher than 8 wt. % in order to obtain a good fracture toughness.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30025-0
       
  • Tribological properties of FeCoCrNiAlBx high-entropy alloys coating
           prepared by laser cladding
    • Authors: Dan-yang Lin; Nan-nan Zhang; Bin He; Guang-wei Zhang; Yue Zhang; De-yuan Li
      Pages: 184 - 189
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Dan-yang Lin, Nan-nan Zhang, Bin He, Guang-wei Zhang, Yue Zhang, De-yuan Li
      FeCoCrNiAlB x (x = 0, 0.25, 0.50, 0.75) coatings were prepared by laser cladding to study the effects of boron on the structure and properties of high-entropy alloys coatings. The microstructure, microhardness, and wear resistance properties of the samples were investigated by scanning electron microscopy, X-ray diffraction, metallographic micro-hardness test, and friction-wear test, respectively, and the mechanism of the wear behavior was also analyzed. The results showed that the high-entropy alloys consisted of BCC phase and eutectic structure, which contained FCC phase and M2 B. With boron addition, the content of BCC phase increased while that of eutectic structure decreased. The wear resistance of the high-entropy coatings was considerably improved with increasing addition of boron, and accordingly, the FeCoCrNiAlB0. 75 coating showed the best wear resistance.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30026-2
       
  • Thermodynamic modeling of Fe-C-Mn-Si alloys
    • Authors: Wei-sen Zheng; Xiao-gang Lu; Yan-lin He; Lin Li
      Pages: 190 - 197
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Wei-sen Zheng, Xiao-gang Lu, Yan-lin He, Lin Li
      The thermodynamic database of the Fe-C-Mn-Si system has been developed in the framework of the CALPHAD approach. The sub-ternary systems have been carefully evaluated and revised based on available experimental data. A satisfactory description of the liquid phase in the Fe-C-Si system has been obtained. The C-Mn-Si system was assessed treating the liquid phase as a substitutional solution. Phase equilibria in the C-Mn-Si system, especially those involving the liquid phase, can be well described. Based on the extrapolation of the experimental data in the quaternary system, the Fe-Mn-Si system has been modified to agree well with experimental data at high temperatures. The comparison between the calculated and measured phase transformation temperatures confirms the reliability of the present quaternary database. Additionally, the solidification process of Fe-0. 16 C-1. 5 Mn-1. 5 Si (wt. %) alloy was simulated by using the thermodynamic database developed.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30027-4
       
  • Hydrogen storage thermodynamic and kinetic characteristics of PrMg12-type
           alloys synthesized by mechanical milling
    • Authors: Jin-liang Gao; Yan Qi; Ya-qin Li; Hong-wei Shang; Dong-liang Zhao; Yang-huan Zhang
      Pages: 198 - 205
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Jin-liang Gao, Yan Qi, Ya-qin Li, Hong-wei Shang, Dong-liang Zhao, Yang-huan Zhang
      To improve the hydrogen storage performance of PrMg12-type alloys * Ni was adopted to replace partially Mg in the alloys. The PrMg11 Ni + x wt. % Ni (x = 100, 200) alloys were prepared via mechanical milling. The phase structures and morphology of the experimental alloys were investigated by X-ray diffraction and transmission electron microscopy. The results show that increasing milling time and Ni content accelerate the formation of nanocrystalline and amorphous structure. The gaseous hydrogen storage properties of the experimental alloys were determined by differential scanning calorimetry (DSC) and Sievert apparatus. In addition, increasing milling time makes the hydrogenation rates of the alloys augment firstly and decline subsequently and the dehydrogenation rate always increases. The maximum capacity is 5. 572 wt. % for the x = 100 alloy and 5. 829 wt. % for the x = 200 alloy, respectively. The enthalpy change (ΔH), entropy change (ΔS) and the dehydrogenation activation energy (E k de) markedly lower with increasing the milling time and the Ni content due to the generation of nanocrystalline and amorphous structure.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30028-6
       
  • Comparison of microstructure and property of high chromium bearing steel
           with and without nitrogen addition
    • Authors: Hai-feng Xu; Feng Yu; Chang Wang; Wan-li Zhang; Jian Li; Wen-quan Cao
      Pages: 206 - 213
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Hai-feng Xu, Feng Yu, Chang Wang, Wan-li Zhang, Jian Li, Wen-quan Cao
      Microstructure and property of bearing steel with and without nitrogen addition were investigated by microstructural observation and hardness measurement after different heat treatment processing. Based on the microstructural observation of both 9Cr18 steel and X90N steel, it was found that nitrogen addition could effectively reduce the amount and size of coarse carbides and also refine the original austenite grain size. Due to addition of nitrogen, more austenite phase was found in X90N steel than in 9Cr18 steel. The retained austenite of X90N steel after quenching at 1050 °C could be reduced from about 60% to about 7% by cold treatment at −73 °C and subsequent tempering, and thus finally increased the hardness up to 60 HRC after low temperature tempering and to 63 HRC after high temperature tempering. Furthermore, both the wear and corrosion resistance of X90N steel were found much more superior than those of 9Cr18 steel, which was attributed to the addition of nitrogen. It was proposed at last that nitrogen alloying into the high chromium bearing steel was a promising way not only to refine the size of both carbides and austenite, but also to achieve high hardness, high wear property and improved corrosion resistance of the stainless bearing steel.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30029-8
       
  • Mechanical and fatigue properties of self-piercing riveted joints in
           high-strength steel and aluminium alloy
    • Authors: Chun-yu Zhang; Rui-bin Gou; Min Yu; Ya-jing Zhang; Yin-hu Qiao; Shu-ping Fang
      Pages: 214 - 221
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Chun-yu Zhang, Rui-bin Gou, Min Yu, Ya-jing Zhang, Yin-hu Qiao, Shu-ping Fang
      Static tensile and fatigue tests were performed on shear and tensile self-piercing riveted aluminium-steel structures to evaluate their mechanical and fatigue properties. The influences of the thickness and the strength of the high-strength steel on mechanical and fatigue performances were investigated based on the tensile and F-N curves of the joints. The results show that mechanical and fatigue properties of the shear self-piercing riveted joints are much better than those of the tensile self-piercing riveted joints. Mechanical and fatigue performances of the two joints were significantly influenced by the thickness and strength of the steel sheet, and were markedly improved when the thickness of steel sheet increased. The steel strength showed significantly different effects on shear and tensile riveted structures, i. e., when the steel strength increased, the strength of the shear structure greatly increased while the tensile structure just had a slight increase in the strength. Fatigue failure generally occurred in the sheet materials and the fatigue crack location changed with increasing the sheet thickness and the sheet strength.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30030-4
       
  • Static recrystallization behavior of 25CrMo4 mirror plate steel during
           two-pass hot deformation
    • Authors: Peng Zhou; Qing-xian Ma
      Pages: 222 - 228
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Peng Zhou, Qing-xian Ma
      The static recrystallization behavior of 25CrMo4 mirror plate steel has been determined by hot compression testing on a Gleeble 1500 thermal mechanical simulation tester. Compression tests were performed using double hit schedules at temperatures of 950–1150 °C, strain rates of 0. 01–0. 5 s−1, and recrystallization time of 1–100 s. Results show that the kinetics of static recrystallization and the microstructural evolution were greatly influenced by the deformation parameters (deformation temperature, strain rate and prestrain) and the initial austenite grain size. Based on the experimental results, the kinetics model of static recrystallization has been generated and the comparison between the experimental results and the predicted results has been carried out. It is shown that the predicted results were in good agreement with the experimental results.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30031-6
       
  • New bainite kinetics of high strength low alloy steel in fast cooling
           process
    • Authors: Xuan-wei Lei; Ji-hua Huang; Shu-hai Chen; Xing-ke Zhao
      Pages: 229 - 233
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Xuan-wei Lei, Ji-hua Huang, Shu-hai Chen, Xing-ke Zhao
      Based on Kolmgorov-Johnson-Mehl-Avrami analysis, a new bainite kinetics of high strength low alloy steel in fast cooling process was developed by utilizing different experimental methods. Upper bainite transformation morphological evolutions at a cooling rate of 8. 3 K/s were directly observed by laser scanning confocal microscopy. This qualitative analysis suggests that bainite packet is more suitable to give a one-dimensional growth model if it is considered as a transformation unit. The nucleation rate of bainite packets in fast cooling process is assumed to give an a priori item. One-dimensional growth model with constant growth rate which is assumed as a function of cooling rate is adopted as well. Thus, the developed new bainite kinetics is simple in expression and contains an adjustable parameter and an empirical parameter. Experimental results show upper bainite and lower bainite transformations in fast cooling processes. Their referential phase volume fractions are calculated by the expanded lever rule on the first derivative dilatometer curves. For the similar transformation mechanisms, upper bainite and lower bainite are considered to give the same kinetics. With considering the Nakamura's equation, the bainite kinetics is fitted with experimental data. Results show that bainite volume fractions and bainite transformation rates can be expressed precisely by the newly developed bainite kinetics.

      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30032-8
       
  • Corrigendum to “Effects of γ-irradiation and Deformation Temperature on
           Tensile Properties of Pb-2 mass% Sb Alloy” [J. Iron Steel Res. Int. 23
           (2016) 733–738]
    • Authors: Gh Mohammed; S. EI-Gamal
      First page: 234
      Abstract: Publication date: February 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 2
      Author(s): Gh Mohammed, S. EI-Gamal


      PubDate: 2017-02-25T19:45:52Z
      DOI: 10.1016/s1006-706x(17)30033-x
       
  • Stress analysis model of strip winding system with a sleeve for a coil of
           thin stainless steel
    • Authors: Yong-hui Park; Kyutae Park; Sung-yeun Won; Wan-kee Hong; Hyun-chul Park
      Pages: 1 - 7
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Yong-hui Park, Kyutae Park, Sung-yeun Won, Wan-kee Hong, Hyun-chul Park
      In a strip winding process, the sleeve is a hollow cylinder that is mounted between a strip coil and a mandrel to maintain uniform coil shape when the strip coil is very thin, but its deformation behavior has not been investigated before. Thus, a finite element (FE) model was presented to calculate the stress distribution in a sleeve and strip coil when 1 — 3 mm-thick stainless steel was wound around the sleeve. The FE model was developed by extending a previous model by adding a sleeve between the mandrel and strip, and by modifying the boundary and interaction conditions. The strip winding process was divided into an initial process and a steady-state process. During the initial process, the minimum and maximum pressure required on the belt wrapper to maintain coil shape by self-friction of the strip was calculated by the FE model when the belt wrapper is ejected at the end of the initial process. After the initial process, an analytical model of the steady-state process was established to calculate the stress distribution and was compared with the FE model to validate it. The suggested analytical model took 11 s to give the same stress distribution that the FE model took 30 d to produce.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30002-x
       
  • Interaction mechanism between coal combustion products and coke in raceway
           of blast furnaces
    • Authors: Chong Zou; Liang-ying Wen; Jun-xue Zhao; Rui-meng Shi
      Pages: 8 - 17
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Chong Zou, Liang-ying Wen, Jun-xue Zhao, Rui-meng Shi
      The interaction mechanism between the combustion products of pulverized coal injected and coke in the raceway of blast furnace was studied through thermodynamic calculation and experiments. The results indicated that additives significantly affected the melting property of coal ash in high temperature zone. Although the unburnt char, raw coal ash, and catalyzed coal ash failed to wet the coke surface, the wettability of the catalyzed coal ash on the coke was greater than that of the raw coal ash. Since the unburnt char had weak reaction with the coke surface, it showed little influence on the surface morphology of the coke. The interaction between the raw coal ash and the coke gave rise to the increase in the pore size on the coke surface. However, the raw coal ash only affected the coke surface and the entrances of the pores owing to its poor fluidity. After being melted, the catalyzed coal ash was expected to immerge into the inside part of the coke and then react with the coke, resulting in an expansion and increase of coke cavities. The raw coal ash and the unburnt char reduced the coke reactivity, while the catalyzed coal ash improved the coke reactivity. Thereinto, the coal ash containing Fe2O3 exhibited a larger influence on the reactivity than that containing CaO.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30003-1
       
  • Effect of screw casing structure on descending of burdens in COREX shaft
           furnace
    • Authors: Zi-long Qiu; Zhi-guo Luo; Heng Zhou; Ren Chen; Feng Wang; Zong-shu Zou
      Pages: 18 - 26
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Zi-long Qiu, Zhi-guo Luo, Heng Zhou, Ren Chen, Feng Wang, Zong-shu Zou
      COREX shaft furnace (SF) is a typical screw feeder with a storage container coupled with eight screw casings and screws. The structure of screw casing plays an important role in the moving behavior of burdens, stress distribution, abrasive wear of screws, and energy consumption during the operation of SF. Therefore, a three-dimensional semi-cylindrical model of actual size of COREX-3000 SF was established based on discrete element method to investigate the influences of screw casing structure. The results show that the increase in the gap between the outside of screw flight and screw casing is beneficial for the smooth operation of SF, resulting in uniform descending velocity along the radius of SF in the lower part, decreasing the size of recirculation region, and alleviating stress concentration in the screw casing. Moreover, raising the gap appropriately is also beneficial to weaken screw abrasive wear, decrease energy consumption, and then prolong the service life of the screws. However, enlarging the gap also leads to more undesired high temperature reduction gas into the SF from melter gasifier, thereby deteriorating the operation of SF. Thus, an ideal distance exists between the outside of the screw flight and the screw casing, which is suggested to be equal to the average of particle diameter.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30004-3
       
  • Production of low-silicon molten iron from high-silica hematite using
           biochar
    • Authors: Hui-qing Tang; Xiu-feng Fu; Yan-qi Qin; Shi-yu Zhao; Qing-guo Xue
      Pages: 27 - 33
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Hui-qing Tang, Xiu-feng Fu, Yan-qi Qin, Shi-yu Zhao, Qing-guo Xue
      A new method of utilizing high-silica hematite to produce low-silicon molten iron was proposed. In this method, FASTMELT, which comprised direct reduction and melt separation processes, was applied, with highly reactive biochar as the reductant in the direct reduction stage. The proposed method was experimentally investigated and the results show that the method is feasible. In the direct reduction stage, ore-char briquette could achieve a metallization rate of 84% — 88% and residual carbon of 0.27 — 0.89 mass% at temperature of 1373 K, biochar mixing ratio of 0.8 — 0.9, and reduction time of 15 min. Some silica particles remained embedded in the iron phase after the reduction. In the melting separation stage, molten iron with a carbon content of 0.02 — 0.03 mass% and silicon content of 0.02 — 0.18 mass% could be obtained from the metallic briquettes under the above-mentioned conditions; the iron recovery rate was 83% — 91% and impurities in the obtained metal were negligible.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30005-5
       
  • Reduction behavior and mechanism of Hongge vanadium titanomagnetite
           pellets by gas mixture of H2 and CO
    • Authors: Wei Li; Gui-qin Fu; Man-sheng Chu; Miao-yong Zhu
      Pages: 34 - 42
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Wei Li, Gui-qin Fu, Man-sheng Chu, Miao-yong Zhu
      Hongge vanadium titanomagnetite (HVTM) pellets were reduced by H2-CO gas mixture for simulating the reduction processes of Midrex and HYL-III shaft furnaces. The influences of reduction temperature, ratio of φ(H2) to φ(CO), and pellet size on the reduction of HVTM pellets were evaluated in detail and the reduction reaction kinetics was investigated. The results show that both the reduction degree and reduction rate can be improved with increasing the reduction temperature and the H2 content as well as decreasing the pellet size. The rational reduction parameters are reduction temperature of 1050 °C, ratio of φ(H2) to φ(CO) of 2.5, and pellet diameter in the range of 8 — 11 mm. Under these conditions (pellet diameter of 11 mm), final reduction degree of 95.51% is achieved. The X-ray diffraction (XRD) pattern shows that the main phases of final reduced pellets under these conditions (pellet diameter of 11 mm) are reduced iron and rutile. The peak intensity of reduced iron increases obviously with the increase in the reduction temperature. Besides, relatively high reduction temperature promotes the migration and coarsening of metallic iron particles and improves the distribution of vanadium and chromium in the reduced iron, which is conducive to subsequent melting separation. At the early stage, the reduction process is controlled by interfacial chemical reaction and the apparent activation energy is 60.78 kJ/mol. The reduction process is controlled by both interfacial chemical reaction and internal diffusion at the final stage and the apparent activation energy is 30.54 kJ/mol.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30006-7
       
  • Morphology, microstructure and decomposition behavior of M2C carbides in
           high speed steel
    • Authors: Xue-feng Zhou; Di Liu; Wang-long Zhu; Feng Fang; Yi-you Tu; Jian-qing Jiang
      Pages: 43 - 49
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Xue-feng Zhou, Di Liu, Wang-long Zhu, Feng Fang, Yi-you Tu, Jian-qing Jiang
      The morphology, microstructure and decomposition behavior of M2C carbides in high speed steels with different chemical compositions have been investigated by scanning electron microscopy, transmission electron microscopy, electron backscatter diffraction and X-ray diffraction. The results show that the morphology and substructure of M2C carbides are very sensitive to chemical compositions of high speed steels. M2C carbides present the plate-like shape in tungsten-molybdenum steel and present the polycrystal orientation in the eutectic cell. In contrast, they show the fibrous shape in molybdenum-base steel and exhibit the monocrystal orientation. Plate-like and fibrous M2C carbides are both metastable and decompose into M6C together with MC at high temperatures. MC nucleates inside the plate-like M2C while it is formed at the fibrous M2C/matrix interface during the decomposition process. Such differences are expected to arise from different compositions of plate-like and fibrous M2C carbides.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30007-9
       
  • Highly ameliorated gaseous and electrochemical hydrogen storage dynamics
           of nanocrystalline and amorphous LaMg12-type alloys prepared by mechanical
           milling
    • Authors: Dian-chen Feng; Hao Sun; Zhong-hui Hou; Dong-liang Zhao; Xi-tao Wang; Yang-huan Zhang
      Pages: 50 - 58
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Dian-chen Feng, Hao Sun, Zhong-hui Hou, Dong-liang Zhao, Xi-tao Wang, Yang-huan Zhang
      Nanocrystalline and amorphous LaMg12-type alloy-Ni composites with a nominal composition of LaMg11 Ni + x wt. % Ni (x = 100, 200) were synthesized via ball milling. The influences of ball milling duration and Ni adding amount x on the gaseous and electrochemical hydrogen storage dynamics of the alloys were systematically studied. Gaseous hydrogen storage performances were studied by a differential scanning calorimeter and a Sievert apparatus. The dehydrogenation activation energy of the alloy hydrides was evaluated by Kissinger method. The electrochemical hydrogen storage dynamics of the alloys was investigated by an automatic galvanostatic system. The H atom diffusion and apparent activation enthalpy of the alloys were calculated. The results demonstrate that a variation in Ni content remarkably enhances the gaseous and electrochemical hydrogen storage dynamics performance of the alloys. The gaseous hydriding rate and high-rate discharge (HRD) ability of the alloys exhibit maximum values with varying milling duration. However, the dehydriding kinetics of the alloys is always accelerated by prolonging milling duration. Specifically, rising milling time from 5 to 60 h makes the hydrogen desorption ratio (a ratio of the dehydrogenation amount in 20 min to the saturated hydrogenation amount) increase from 57% to 66% for x=100 alloy and from 57% to 70% for x = 200. Moreover, the improvement of gaseous hydrogen storage kinetics is attributed to the descending of dehydrogenation activation energy caused by the prolonging of milling duration and growing of Ni content.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30008-0
       
  • Influence of on-line tempering parameters on microstructure of
           medium-carbon steel
    • Authors: Hua Zhang; Yan-xin Wu; Jian-xun Fu; Jie Xu; Qi-jie Zhai
      Pages: 59 - 66
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Hua Zhang, Yan-xin Wu, Jian-xun Fu, Jie Xu, Qi-jie Zhai
      A new process involving ultra-fast cooling (UFC) and on-line tempering (OLT) was proposed to displace austempering process, which usually implements in a salt/lead bath and brings out serious pollution in the industrial application. The optimization of the new process, involving the evolution of the microstructure of medium-carbon steel during various cooling paths, was studied. The results show that the cooling path affected the final microstructure in terms of the fraction of pearlite, grain size and distribution of cementite in pearlite. Increasing the cooling rate or decreasing the OLT temperature contributes to restraining the transformation from austenite to ferrite, and simultaneously retains more austenite for the transformation of pearlite. It is also noted that bainite was observed in the microstructure at the cooling rate of 45 °C/s and the OLT temperature of 500 °C. Through either increasing the cooling rate or decreasing the OLT temperature, the distribution of cementite in pearlite is more dispersed and grain is refined. Taking the possibility of industrial applications into account, the optimal process of cooling at 45 °C/s followed by OLT at 600 °C after hot rolling was determined, which achieves a microstructure containing nearly full pearlite with an average grain size of approximately 7 μm and a homogeneously dispersed distribution of cementite in pearlite.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30009-2
       
  • Dependence of tensile properties on microstructural features of
           bimodal-sized ferrite/cementite steels
    • Authors: Jiang-li Ning; Yun-li Feng; Ming-ming Wang; Shen-bai Zheng; Jie Li
      Pages: 67 - 76
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Jiang-li Ning, Yun-li Feng, Ming-ming Wang, Shen-bai Zheng, Jie Li
      A medium-carbon steel was processed through different warm rolling techniques, and the microstructural features with bimodal grain size distribution were found to be different. The combination of strength and ductility was ameliorated in the steel processed through warm rolling characterized by biaxial reduction. The enhanced strength is attributed to the densely distributed fine intragranular cementite particles and the small grain size in the coarse grain regions. The enhanced uniform elongation is due to the improved work hardening behavior at the large-strain stage. This work hardening behavior is predominantly ascribed to the finely dispersed intragranular particles. The relatively small grain size with nearly equiaxed shape in the coarse grain regions helps stabilize the uniform deformation to a large strain.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30010-9
       
  • Oxidation resistance, thermal expansion and area specific resistance of
           Fe-Cr alloy interconnector for solid oxide fuel cell
    • Authors: Liu-zhen Bian; Zhi-yuan Chen; Li-jun Wang; Fu-shen Li; Kuo-chih Chou
      Pages: 77 - 83
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Liu-zhen Bian, Zhi-yuan Chen, Li-jun Wang, Fu-shen Li, Kuo-chih Chou
      It is promising for metal especially ferritic stainless steel (FSS) to be used as interconnector when the solid oxide fuel cell (SOFC) is operated at temperature lower than 800 °C. However, there are many challenges for FSS such as anti-oxidant, poisoning to cathode and high area specific resistance (ASR) when using as SOFC interconnector. The effect of Cr content (12 — 30 mass%) in Fe-Cr alloys on thermal expansion coefficient (TEC), oxidation resistance, microstructure of oxidation scale and ASR was investigated by thermo-gravimetry, scanning electron microscopy, energy dispersive spectroscopy and four-probe DC technique. The TEC of Fe-Cr alloys is (11 — 13) × 10−6 K−1, which excellently matches with other SOFC components. Alloys have excellent oxidation resistance when Cr content exceeds 22 mass% because of the formation of chromium on the surface of alloy. The oxidation rate constants k d and k s decrease rapidly with increasing the Cr content and then increase slowly when the Cr content is higher than 22 mass%. The kinetic results indicate that Cr evaporation must be considered at high temperature for Fe-Cr alloys. After the alloys were oxidized in air at 800 °C for 500 h, log(ASR/T) (T is the absolute temperature) presents linear relationship with 1/T and the conduct activation energy is 0.6 — 0.8 eV (Cr16-30). Optimal Cr content is 22 — 26 mass% considering the oxidation resistance and ASR.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30011-0
       
  • Microstructure and texture evolution during recrystallization of
           low-carbon steel sheets
    • Authors: Dong-dong Zhuang; Lei-gang Wang; Yao Huang; Xiao-min Li; Hua-yang Zhang; De-wei Ren
      Pages: 84 - 90
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Dong-dong Zhuang, Lei-gang Wang, Yao Huang, Xiao-min Li, Hua-yang Zhang, De-wei Ren
      Aluminum killed low-carbon steel sheets were cold rolled at different reduction ratios and annealed using different temperatures and holding time. The Vickers hardness was examined. The results show that when cold rolling reduction ratios increase from 40% to 81%, recrystallization temperatures decrease from 602 °C to 572 °C during 4 h isochronal annealing, as well recrystallization holding time decreases from 117 min to 5 min during isothermal annealing at 610 °C. All recrystallization temperatures and holding time can be calculated using the annealing experiment results. Microstructure was examined through electron backscattered diffraction (EBSD). The results show that as rolling direction preferentially grows, equiaxed grains grow into cake-type during recrystallization. Cake-type grains are more beneficial to obtaining ideal <111>//ND (normal direcrtion) orientation texture. {111} orientation grains nucleate and grow up preferentially. Deformation grains of {111} <110> orientations grow into new recrystallization grains of {111} <123> and {111} <112> during recrystallization. Texture formation can be explained by directional nucleation.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30012-2
       
  • Microstructure, texture and precipitates of grain-oriented silicon steel
           produced by thin slab casting and rolling process
    • Authors: Si-qian Bao; Yang Xu; Gang Zhao; Xiang-bin Huang; Huan Xiao; Chuan-long Ye; Na-na Song; Qing-ming Chang
      Pages: 91 - 96
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Si-qian Bao, Yang Xu, Gang Zhao, Xiang-bin Huang, Huan Xiao, Chuan-long Ye, Na-na Song, Qing-ming Chang
      A grain-oriented silicon steel strip with AlN as main inhibitor was produced by thin slab casting and rolling (TSCR) process. The microstructure, texture and precipitates of the hot-rolled strip were investigated by use of optical microscope (OM), X-ray diffractometer, transmission electron microscope (TEM) and energy dispersive spectroscope (EDS). The result shows that the microstructure and texture exhibit a through-thickness gradient similar to that of the hot-rolled strip produced by conventional high-temperature slab-reheating process; the preferred orientation varies from {110} <001> in the surface layer to {001} <110> in the center layer, and the Goss texture with a maximum intensity mainly concentrates on the surface layer. In addition, some other texture components, for example rotated Goss texture, form in the 1/4 thickness layer, which are not observed in the hot-rolled strip produced by conventional high-temperature slab-reheating process. The precipitates in the hot-rolled strip are mainly (Mn, Cu)S and AlN compound particles with dimension of 100 — 200 nm, and the fine precipitates are significantly less than that in the hot-rolled strip produced by conventional high-temperature slab-reheating process. Moreover, the areal density of the fine precipitates in the center layer is more than that in the surface layer.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30013-4
       
  • Preparation of porous titanium materials by powder sintering process and
           use of space holder technique
    • Authors: Xin-sheng Wang; Zhen-lin Lu; Lei Jia; Jiang-xian Chen
      Pages: 97 - 102
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Xin-sheng Wang, Zhen-lin Lu, Lei Jia, Jiang-xian Chen
      It is shown that an adapted powder sintering process can successfully prepare a 24.0%—35.5% porous titanium composite using 20 μm Ti powder and rice husk particles ranging in size between 250 μm and 600 μm. The phase constituents of the porous Ti composite samples were determined by X-ray diffraction (XRD) pattern sintered at 1250 °C. The generation of silicon in the form of a TiSi2 solid solution, injected into the substrate, illustrates the solid solution strengthening effect. The average grain size of the tested sample and the grain boundary area increase along with the silicon content. This indicates that silicon is dispersed within the green compact of Ti. As the distance from a hole becomes greater, the nanohardness increases until it reaches a maximum hardness of 3.5 GPa at approximately 1.5 mm. This may be due to the solid solution strengthening of SiO2. However, nanohardness is 3.3 GPa at a distance of approximately 0.5 mm from a hole's edge. The compressive strength is measured to be in the range of 440 — 938 MPa. The strain reaches 14.8% — 16.6% under compression testing. A large number of cleavage steps appear following a fracture. The observed fracture is a brittle fracture. Porous Ti composites with about 36% porosity have promising potential biomaterial applications, specifically related to bone implants and biological bearings.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30014-6
       
  • A first-principles study on electronic structures and elastic properties
           of metal doped α-Fe(N) high nitrogen steel
    • Authors: Ji-chun Yang; Xiang-jun Liu; Gui-xiao Jia; Xiao-yang Fu
      Pages: 103 - 110
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Ji-chun Yang, Xiang-jun Liu, Gui-xiao Jia, Xiao-yang Fu
      The binding energies, electronic structures and elastic properties of Ti, V, Cr, Mn, Co, Ni and Mg doped α-Fe(N) systems have been investigated using a first-principles method. The calculated results show that the dopings of Ti, V, Cr and Co improve the stability of α-Fe(N), and the stability of α-Fe(N) is slightly weakened by Mn and Ni, and the doping of Mg is disadvantageous. For Ti, V, Cr and Mn doped α-Fe(N) systems in which the doping metals are on the left side of Fe in the element periodic table and α-Fe(N) systems doped by Co and Ni on the right side of Fe, their corresponding cohesive forces decrease with decreasing atomic radius of the doping species. The obvious interaction exists among M3d, Fe4s3p3d and N2p. In these doping systems, metal atoms lose electrons, while N gains electrons. Dopings of Ti, V, Cr and Mn in α-Fe(N) strengthen the interaction between N and the surrounding metals, and it is not apparent for the dopings of Co, Ni and Mg. Elastic calculations of Fe15 MN systems show that, except for the Fe15 MgN system, shear modulus G and Young modulus E of Fe15 MN systems are improved, and the bulk modulus B slightly decreases, namely, total elastic properties are enhanced. The magnitude change rule of E reflecting the cohesive force between atoms is consistent with that for the binding energies.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30015-8
       
  • Tensile deformation behavior of high strength anti-seismic steel with
           multi-phase microstructure
    • Authors: Zheng-yun Zhang; Jian-chun Cao; Zhong-hua Zhong; Xiao-long Zhou; Wei Chen; Yin-hui Yang
      Pages: 111 - 120
      Abstract: Publication date: January 2017
      Source:Journal of Iron and Steel Research, International, Volume 24, Issue 1
      Author(s): Zheng-yun Zhang, Jian-chun Cao, Zhong-hua Zhong, Xiao-long Zhou, Wei Chen, Yin-hui Yang
      To investigate the tensile deformation behavior of high strength anti-seismic steel with multi-phase microstructure, tensile tests with strains of 0.05, 0.12 and 0.22 were performed at room temperature. Microstructure of tested steels was observed by means of optical microscopy (OM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Tensile mechanical properties of tested steels were obtained, and the influence of bainite content on deformation behavior was also discussed. Meanwhile, the deformation mechanism of steel with three kinds of microstructures of bainite, pearlite and ferrite was analyzed. Results show that tested steel with high volume fraction of bainite exhibits a continuous deformation behavior, and this may be attributed to a higher bainite volume fraction and a lower mobile dislocation density. The morphology of microstructure will influence the mechanical properties of tested steels. An increasing content of bainite can improve the tensile strength, but reduce the plasticity and toughness of the tested steels. In the deformation process of 0.039Nb steel, the ferrite and bainite have priorities to deform, and the deformation exhibits co-deformation of all microstructures in the later stage of deformation. In the deformation process of 0.024Nb-0.032V steel, the ferrite and pearlite have priorities to deform, and the deformation exhibits co-deformation of all microstructures in the later stage of deformation.

      PubDate: 2017-01-25T11:02:25Z
      DOI: 10.1016/s1006-706x(17)30016-x
       
  • Modelling Effect of Circulation Flow Rate on Inclusion Removal in RH
           Degasser
    • Authors: Shu-guo ZHENG; Miao-yong ZHU
      Pages: 1243 - 1248
      Abstract: Publication date: December 2016
      Source:Journal of Iron and Steel Research, International, Volume 23, Issue 12
      Author(s): Shu-guo ZHENG, Miao-yong ZHU
      Based on the similarity principles, a 1 : 7 scale physical model was established to study the behavior of molten steel flow and inclusion removal in a 145 t Rheinsahl-Heraeus (RH) degasser. On the basis of the quantitative measurements of the circulation flow rate and inclusion removal under various lifting gas flow rates, the effect of circulation flow rate on inclusion removal was investigated in the RH degasser. The inclusion removal rate shows the trend of first increase and then decrease twice with increasing the circulation flow rate when the circulation flow rates are smaller than 104. 7 L/min. Whereas, the inclusion removal rate increases again with the further increase in circulation flow rate when the circulation flow rate is larger than 104. 7 L/min. At lower circulation flow rates, inclusions are mainly removed by Stokes flotation to the slag/steel interface after inclusions are transferred near the slag/steel interface by the circulation flow. At higher circulation flow rates, the collision and aggregation of inclusions improves the inclusion removal efficiency. With the further increase in the circulation flow rate, inclusions are mainly removed by following the turbulent fluctuation (turbulent diffusion) to the slag/steel interface after inclusions are transferred near the slag/steel interface by the circulation flow.

      PubDate: 2016-12-23T21:05:49Z
      DOI: 10.1016/s1006-706x(16)30183-2
       
  • Transverse Bending Characteristics in U-channel Forming of Tailor Rolled
           Blank
    • Authors: Hua-wei ZHANG; Ying-ping GUAN; Jia-lu WU; Xiang-hua LIU
      Pages: 1249 - 1254
      Abstract: Publication date: December 2016
      Source:Journal of Iron and Steel Research, International, Volume 23, Issue 12
      Author(s): Hua-wei ZHANG, Ying-ping GUAN, Jia-lu WU, Xiang-hua LIU
      Research on the formability of tailor rolled blank (TRB) is of good practical significance and application value because of the enormous potential of TRB in the aspect of automobile lightweight. However, the forming of TRB is problematic because of the varying properties; especially, springback is a main challenge. The transverse bending (bending axis is perpendicular to the rolling direction) of TRB U-channel was studied through simulation and experiment. The forming characteristics of TRB U-channel during transverse bending were analyzed. The mechanisms of forming defects, including bending springback and thickness transition zone (TTZ) movement, were revealed. On this basis, effects of blank geometric parameters on springback and TTZ movement were discussed. The results indicate that springback and TTZ movement happen during transverse bending of TRB U-channel. Nonuniform stress distribution is the most fundamental reason for the occurrence of springback of TRB during transverse bending. Annealing can eliminate nonuniform stress distribution, and thus diminish springback of TRB, especially springback on the thinner side. Therefore, springback of the whole TRB becomes more uniform. However, annealing can increase the TTZ movement. Blank thickness and TTZ position are the main factors affecting the formability of TRB U-channel during transverse bending.

      PubDate: 2016-12-23T21:05:49Z
      DOI: 10.1016/s1006-706x(16)30184-4
       
  • Recycling of High Ferrous Bauxite Reducing Slag for Synthesis of CaAl2 Si2
           O8-Al2 O3-CaAl12 O19 Composite
    • Authors: Ying-yi ZHANG; Yuan-hong QI; Zong-shu ZOU
      Pages: 1255 - 1261
      Abstract: Publication date: December 2016
      Source:Journal of Iron and Steel Research, International, Volume 23, Issue 12
      Author(s): Ying-yi ZHANG, Yuan-hong QI, Zong-shu ZOU
      CaAl2Si2O8-Al2 O3-CaAl12O19 (CAS2-Al2 O3-CA6) composite was synthesized through reaction sintering alumina and bauxite reducing slag. The CAS2-Al2O3-CA6 composite was mainly composed of α-Al2O3, CAS2, and CA6. Gehlenite (Ca2 Al2SiO7, C2AS) phase was effectively transformed to CAS2 and CA6 through high-temperature reaction sintering under weak oxidizing atmosphere at 1400 °C for 4 h. SEM (scanning electron microscopy) and EDS (energy dispersive spectroscopy) analysis indicated that black and needle-shaped Al2 O3, rhombic or irregular polygonal-shaped FeAl2 O4, and glassy phase Ca2 Al2SiO7 disappeared after the reaction sintering. The light gray and flaky hexagon crystals of CaAl12 O19 (10 μm) and the grainy particles of Al2O3 (2–7 μm) were observed in the CAS2-Al2O3-CA6 composite. The gray crystals of CAS2 act as the binding phase and are distributed around CA6 and Al2O3. CAS2-Al2 O3-CA6 composite exhibits high refractoriness and service temperature, which are 1650 °C and 1450 °C, respectively. Reaction sintering of alumina and bauxite reducing slag is a feasible method for the synthesis of CAS2-Al2 O3-CA6 composite.

      PubDate: 2016-12-23T21:05:49Z
      DOI: 10.1016/s1006-706x(16)30185-6
       
 
 
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