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  Subjects -> ENVIRONMENTAL STUDIES (Total: 755 journals)
    - ENVIRONMENTAL STUDIES (690 journals)
    - POLLUTION (22 journals)
    - TOXICOLOGY AND ENVIRONMENTAL SAFETY (34 journals)
    - WASTE MANAGEMENT (9 journals)

ENVIRONMENTAL STUDIES (690 journals)            First | 1 2 3 4 5 6 7     

International Journal of Chinese Culture and Management     Hybrid Journal   (1 follower)
International Journal of Corrosion     Open Access   (10 followers)
International Journal of Critical Infrastructures     Hybrid Journal   (3 followers)
International Journal of Disaster Risk Reduction     Hybrid Journal   (3 followers)
International Journal of Disaster Risk Science     Open Access   (9 followers)
International Journal of Ecological Economics and Statistics     Full-text available via subscription   (1 follower)
International Journal of Ecology     Open Access   (8 followers)
International Journal of Ecology & Development     Full-text available via subscription   (1 follower)
International Journal of Energy and Environmental Engineering     Open Access   (2 followers)
International Journal of Environment     Open Access   (3 followers)
International Journal of Environment and Health     Hybrid Journal   (7 followers)
International Journal of Environment and Pollution     Hybrid Journal   (6 followers)
International Journal of Environment and Sustainable Development     Hybrid Journal   (13 followers)
International Journal of Environment and Waste Management     Hybrid Journal   (6 followers)
International Journal of Environment, Workplace and Employment     Hybrid Journal   (3 followers)
International Journal of Environmental Engineering     Hybrid Journal   (5 followers)
International Journal of Environmental Health Engineering     Open Access  
International Journal of Environmental Health Research     Hybrid Journal   (2 followers)
International Journal of Environmental Policy and Decision Making     Hybrid Journal   (10 followers)
International Journal of Environmental Protection     Open Access   (12 followers)
International Journal of Environmental Research and Public Health     Open Access   (13 followers)
International Journal of Environmental Science and Technology     Hybrid Journal   (4 followers)
International Journal of Environmental Studies     Hybrid Journal   (11 followers)
International Journal of Exergy     Hybrid Journal   (3 followers)
International Journal of Forest, Soil and Erosion     Open Access   (3 followers)
International Journal of Global Environmental Issues     Hybrid Journal   (4 followers)
International Journal of Global Warming     Hybrid Journal   (4 followers)
International Journal of Greenhouse Gas Control     Partially Free   (5 followers)
International Journal of Health Planning and Management     Hybrid Journal   (6 followers)
International Journal of Hygiene and Environmental Health     Hybrid Journal   (5 followers)
International Journal of Logistics Research and Applications: A Leading Journal of Supply Chain Management     Hybrid Journal   (9 followers)
International Journal of Philosophical Studies     Hybrid Journal   (2 followers)
International Journal of Phytoremediation     Hybrid Journal   (1 follower)
International Journal of Process Systems Engineering     Hybrid Journal   (1 follower)
International Journal of Recycling of Organic Waste in Agriculture     Open Access   (1 follower)
International Journal of Regulation and Governance     Hybrid Journal   (2 followers)
International Journal of Reliability and Safety     Hybrid Journal   (5 followers)
International Journal of Renewable Energy Development     Open Access   (4 followers)
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International Journal of Soil, Sediment and Water     Open Access   (8 followers)
International Journal of Stress Management     Full-text available via subscription   (8 followers)
International Journal of Sustainable Construction Engineering and Technology     Open Access   (7 followers)
International Journal of Sustainable Engineering     Hybrid Journal   (7 followers)
International Journal of Sustainable Materials and Structural Systems     Hybrid Journal   (5 followers)
International Journal of Sustainable Society     Hybrid Journal   (7 followers)
International Journal of Testing     Hybrid Journal   (1 follower)
International Journal of the Commons     Open Access   (2 followers)
International Journal of Toxicology     Hybrid Journal   (5 followers)
International Journal of Water Resources and Environmental Engineering     Open Access  
International Review of Environmental and Resource Economics     Full-text available via subscription  
International Studies in the Philosophy of Science     Hybrid Journal   (10 followers)
Interventions : International Journal of Postcolonial Studies     Hybrid Journal   (5 followers)
Investigación ambiental Ciencia y política pública     Open Access   (1 follower)
IOP Conference Series: Earth and Environmental Science     Open Access   (7 followers)
Iranian Journal of Environmental Health Science & Engineering     Open Access   (1 follower)
Iranian Journal of Health and Environment     Open Access   (2 followers)
Iranian Studies     Hybrid Journal   (8 followers)
Irish Educational Studies     Hybrid Journal   (1 follower)
Irish Journal of Earth Sciences     Full-text available via subscription  
Irish Political Studies     Hybrid Journal   (7 followers)
ISLE: Interdisciplinary Studies in Literature and Environment     Hybrid Journal   (2 followers)
Isotopes in Environmental and Health Studies     Hybrid Journal   (2 followers)
Israel Studies     Full-text available via subscription   (5 followers)
ISRN Ecology     Open Access   (3 followers)
ISRN Environmental Chemistry     Open Access  
Italian Studies     Hybrid Journal   (6 followers)
Jahangirnagar University Environmental Bulletin     Open Access  
Journal of Bioremediation & Biodegradation     Open Access   (2 followers)
Journal of Earth Science & Climatic Change     Open Access   (8 followers)
Journal of Petroleum & Environmental Biotechnology     Open Access   (2 followers)
Journal of Waste Water Treatment & Analysis     Open Access   (10 followers)
Journal of Advances in Environmental Health Research     Open Access  
Journal of Agricultural and Environmental Ethics     Hybrid Journal   (7 followers)
Journal of Agricultural Biotechnology and Sustainable Development     Open Access  
Journal of Agriculture and Environment     Open Access  
Journal of Agriculture and Environment for International Development     Open Access   (5 followers)
Journal of Agrobiology     Open Access   (2 followers)
Journal of Applied Ecology     Hybrid Journal   (110 followers)
Journal of Applied Meteorology and Climatology     Full-text available via subscription   (7 followers)
Journal of Applied Psychoanalytic Studies     Hybrid Journal   (1 follower)
Journal of Applied Sciences and Environmental Management     Open Access  
Journal of Applied Sciences in Environmental Sanitation     Open Access   (4 followers)
Journal of Applied Toxicology     Hybrid Journal   (8 followers)
Journal of Applied Volcanology     Open Access   (6 followers)
Journal of Arid Environments     Hybrid Journal   (8 followers)
Journal of Asian Studies     Full-text available via subscription   (20 followers)
Journal of Biochemical and Molecular Toxicology     Hybrid Journal   (5 followers)
Journal of Black Studies     Hybrid Journal   (3 followers)
Journal of Chemical Ecology     Hybrid Journal   (1 follower)
Journal of Chemical Health and Safety     Hybrid Journal   (2 followers)
Journal of Climate     Full-text available via subscription   (20 followers)
Journal of Coastal Research     Full-text available via subscription   (9 followers)
Journal of Contaminant Hydrology     Hybrid Journal   (9 followers)
Journal of Contemporary European Studies     Hybrid Journal   (3 followers)
Journal of East African Natural History     Full-text available via subscription   (3 followers)
Journal of Ecology     Hybrid Journal   (34 followers)
Journal of Ecosystems     Open Access   (4 followers)
Journal of Empirical Legal Studies     Hybrid Journal   (5 followers)
Journal of Environment and Earth Science     Open Access   (8 followers)
Journal of Environment and Ecology     Open Access   (9 followers)

  First | 1 2 3 4 5 6 7     

Journal of Iron and Steel Research, International    [9 followers]  Follow    
  Full-text available via subscription Subscription journal
     ISSN (Print) 1006-706X
     Published by Elsevier Homepage  [2556 journals]   [SJR: 0.586]   [H-I: 13]
  • Development of Mathematical Model for Control Wear in Backup Roll for Hot
           Strip Mill
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): R. Servin-Castañeda , A.M. Garcia-Lara , R.D. Mercado-Solís , C.A. Vega-Lebrun
      The precision of strip flatness depends on several factors; wear of rolls is one of the main variables that have influence on the surface quality of the strip. The wear of the rolls represents a complex friction condition, sometimes the wear in the backup roll is not analyzed because the strip is not in contact with the backup roll; however, after several campaigns of rolling, the wear in the backup roll becomes dangerous because the pressure distribution is not uniform. Investigation of mechanism of the surface deterioration of the backup roll for the hot strip rolling is very important for the development of the automatic strip shape control system used in hot strip mills. A mathematical model is developed considering the Hertzian pressure distribution between two cylinders with parallel axes. It is used in real time for calculating the wear in the backup roll and in this manner take decisions for preventing finished product reworking or damage of equipments, which result in accidents caused by excessive wear in the backup rolls.


      PubDate: 2014-01-08T04:34:27Z
       
  • Effect of Carbon Content on Stacking Fault Energy of Fe-20Mn-3Cu TWIP
           Steel
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Xian PENG , Ding-yi ZHU , Zhen-ming HU , Ming-jie WANG , Long-long LIU , Hai-jun LIU
      The influence of carbon content on the stacking fault energy (SFE) of Fe–20Mn–3Cu twinning-induced plasticity (TWIP) steel was investigated by means of X-ray diffraction peak-shift method and thermodynamic modeling. The experimental result indicated that the stacking fault probability decreases with increasing carbon addition, the SFE increases linearly when the carbon content in mass percent is between 0. 23% and 1.41%. The thermodynamic calculation results showed that the SFE varied from 22. 40 to 29. 64 mJ · m−2 when the carbon content in mass percent changes from 0. 23 % to 1.41%. The XRD analysis revealed that all steels were fully austenitic before and after deformation, which suggested that TWIP effect is the predominant mechanism during the tensile deformation process of Fe-20Mn-3Cu-XC steels.


      PubDate: 2014-01-08T04:34:27Z
       
  • Effects of Mo Contents in Matrix on Microstructure and Properties of
           Vanadium Carbide Coating Formed by Thermal Diffusion Treatment
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Zhi-tao HUANG , Wen-huai TIAN
      Thermal diffusion salt-bath vanadizing was finished for Cr12MoV die steel, in order to investigate the properties of vanadium carbide coatings related with the Mo contents in Crl2MoV die steel. Scanning electron microscopic observation reveals that Mo can decrease the growth rate of coating as a carbide forming element. Besides, Mo element can promote grain refinement of the coating. X-ray diffraction analysis shows that the different Mo contents have no influence on the phase structure of the coatings. Energy dispersive spectrum analysis and mechanical properties test show that Mo can diffuse into the coating and make a strengthening effect on the coating.


      PubDate: 2014-01-08T04:34:27Z
       
  • Effect of Thermomechanical Parameters on Σ3n Grain Boundaries and
           Grain Boundary Networks of a New Superaustenitic Stainless Steel
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Hong-ying SUN , Zhang-jian ZHOU , Man WANG , Xiao LI
      Hot compression tests were conducted in a temperature range of 800 – 1100 °C and strain rate range of 0.1 – 10 s−1 using a Gleeble 3500 thermomechanical simulator to investigate the influence of hot deformation parameters (temperatures, strain rates and strains) on the grain boundary network evolution of a new grade Fe-Cr-Ni superaustenitic stainless steel. The results showed that a dominant effect of deformed temperature is Σ3 n (n = 0, 1, 2, 3) boundaries population increased with decreasing temperature, while they first increased and then reduced with increasing strain and strain rate. Interestingly, besides Σ3 n (n = 1, 2, 3) twin grain boundaries, some Σ1 boundaries could interrupt grain boundaries network effectively, which enhance material performances. But they are scarcely reported. The misorientation of some segments LAGBs in the deformed microstructure (pancaked grains) increased and slid to high angle grain boundaries with increasing the fraction of recrystallized grains during hot deformation.


      PubDate: 2014-01-08T04:34:27Z
       
  • Study and Application of Bottom Blowing Technique of Combined Blowing
           Converter
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Li-bin YANG , Liu LIU , Xing-li JIAO , Pu-qiao TONG
      The water modelling experiments of 300 t converter concerning combined blowing parameters, the number, and configuration of bottom nozzles are carried out. The results show that the arrangement of 16 bottom nozzles at 0. 40D and 0. 45D (hearth diameter) concentric circles is the reasonable solution. The combined blowing steelmaking technique of 300 t converter has been developed through experiments and studies relating to optimizing the top-bottom combined blowing pattern, the number and configuration of the bottom nozzles, the type selection of bottom nozzle, and bottom nozzle maintenance techniques. The results show that the product of w [c] • w [o] at endpoint is reduced from 0.00262 to 0.00243, average TFe content is decreased by 2%, phosphorus distribution is raised from 70. 85 to 78. 95, sulfur distribution is raised from 3.43 to 4.32 and manganese content is raised by 0. 02%.


      PubDate: 2014-01-08T04:34:27Z
       
  • Microstructure and Abrasive Wear Behavior of Medium Carbon Low Alloy
           Martensitic Abrasion Resistant Steel
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Xiang-tao DENG , Zhao-dong WANG , Yi HAN , Hui ZHAO , Guo-dong WANG
      The effect of processing parameters such as hot rolling and heat treatment on microstructure and mechanical properties was investigated for a new 0. 27 mass % C and Ni, Mo-free low alloy martensitic abrasion resistant steel. The three-body impact abrasive wear behavior was also analyzed. The results showed that two-step controlled rolling besides quenching at 880 °C and tempering at 170 °C could result in optimal mechanical property: the Brinell hardness, tensile strength, elongation and −40 °C impact toughness were 531, 1530 MPa, 11.8% and 58 J, respectively. The microstructure was of fine lath martensite with little retained austenite. Three-body impact abrasive wear results showed that wear mechanism was mainly of plastic deformation fatigue when the impact energy was 2 J, and the relative wear resistance was 1. 04 times higher than that of the same grade compared steel under the same working condition. The optimal hardness and toughness match was the main reason of higher wear resistance.


      PubDate: 2014-01-08T04:34:27Z
       
  • Interstitial Solution Carbon Concentration and Defects of Ti + Nb ULC-BH
           Steel by Internal Friction and Positron Annihilation Methods
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Ji-ping CHEN , Yong-lin KANG
      The interstitial solution carbon concentration and defects in continuously annealed Ti+Nb bearing ULC-BH (ultra-low carbon bake hardening) steel samples are investigated by multi-functional internal friction apparatus, positron annihilation lifetime spectroscopy (PALS) and coincidence Doppler broadening spectroscopy (CDBS). The relationship of internal friction peaks, interstitial solution carbon concentrations and movable dislocations in the samples under different conditions is analyzed. A correlation of lifetime component τ1 values with interstitial solution carbon concentrations in the samples for different continuous annealing processes is established, while a correlation of lifetime component τ2 values with multi-vacancies, vacancy clusters, microvoids and other types of defects for various continuous annealing processes is also demonstrated. Furthermore, the average lifetime results illustrate the overall defect densities for various continuous annealing processes. The CDBS analysis reflects the chemical surroundings of the defects at the annihilation sites and reveals that the peak heights of the ratio curves relate to the total number of defects such as interstitial carbon atoms, dislocations, vacancies and other types of defects. The results show that internal friction, PALS and CDBS are effective techniques to identify and characterize the interstitial solution carbon concentration, multi-vacancies, vacancy clusters, microvoids and other types of microscopic defects in annealed Ti+Nb bearing ULC-BH steel.


      PubDate: 2014-01-08T04:34:27Z
       
  • Upgrade Rolling Based on Ultra Fast Cooling Technology for C-Mn Steel
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Xiao-guang ZHOU , Zhen-yu LIU , Sheng-yong SONG , Di WU , Guo-dong WANG
      By measuring the expansion curves of a C-Mn steel at different cooling rates by using an MMS-300 thermomechanical simulator, continuous cooling transformation curves were obtained. The new process “ultra fast cooling+laminar cooling” was simulated and the effects of ultra fast cooling ending temperature on microstructure had also been investigated. The hot rolling experiment was done by adopting “high temperature rolling+forepart ultra fast cooling” technologies at laboratory scale. The results revealed that ultra fast cooling can delay the decrease of dislocation density and refine ferrite grains. Diversity control of the microstructure and phase transformation strengthening can be realized by changing the ultra fast cooling ending temperature. With the decrease of ultra fast cooling ending temperature, the strength and toughness increase, but plasticity does not decrease obviously. The new technique can improve the yield strength by over 50 MPa. Therefore, the upgrade of mechanical properties of C-Mn steel can be realized by using “high temperature rolling+ultra fast cooling+laminar cooling” technique. Compared with “low temperature rolling with large deformation degree” technique, this new technology can decrease the rolling force and increase the production efficiency.


      PubDate: 2014-01-08T04:34:27Z
       
  • Influence of Chromium on Mechanical Properties and CO2/H2S Corrosion
           Behavior of P110 Grade Tube Steel
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Hui-bin WU , Li-fu LIU , Li-dong WANG , Yue-ting LIU
      Four kinds of P110 grade tube steels containing different chromium contents were designed to probe the influence of Cr on the properties of tube steel. The microstructure, mechanical properties and corrosion behavior of the four kinds of P110 grade tube steels were studied deeply and thoroughly. The analysis of the mechanical properties indicated that tensile strength and yield strength of the steel plates were improved, while transverse and longitudinal impact energy and elongation first increased and then decreased when Cr content rose. The impact energy and elongation reached the peak when Cr content was 1%. Cr precipitates were found only in 3 % Cr steel, with (Nb, Ti) (C, N) or Nb(C, N) as the core of precipitation and then grew up. The corrosion experiments demonstrated that the scales on the four steels had a two-layer structure under the corrosion of CO2 and H2S. The outer layer was mainly composed of FeS or FeS1–x and the inner layer consisted of FeCO3 and Cr compounds. Cr was rich in the inner layer and the Cr content of the inner layer increased with the Cr content in matrix. The enriched Cr enhanced the compactness of the scales, further hindering the diffusion of ions from liquid to the surface of steel, thus reducing corrosion rate.


      PubDate: 2014-01-08T04:34:27Z
       
  • Reduction of Oxide Scale with Hydrogen
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Xiao-jiang LIU , Guang-ming CAO , Yong-quan HE , Ming YANG , Zhen-yu LIU
      During hot rolling process metals will inevitably oxidize because of high temperature and air condition. In order to guarantee the surface quality, acid pickling is applied to remove the oxide scale while waste acid will do harm to the environment. Faced with the problem, by means of reduction process of hot-rolled plates, the oxide scale will be reduced to iron, so that acid pickling is unnecessary. One pass cold rolling procedure was applied. The compression ratios of hot-rolled plates with oxide scale were 10%, 18%, 26% and 31%, respectively. After that, samples mentioned above including a sample without deformation were separately reduced under hydrogen atmosphere condition (5% H2+95% Ar in volume percent) at 600–1000 °C. The thermal gravimetric apparatus (TGA) was used to establish accurate experimental condition and obtain complete mass loss data. Field emission electron probe microanalysis (EPMA) was applied to analyze scale morphology change and composition distribution through the oxide scale. It was found that the sample with 26 % compression ratio could be reduced completely at 900 °C which was favorable to galvanization.


      PubDate: 2014-01-08T04:34:27Z
       
  • A New Series of Mo-free 21. 5Cr-3. 5Ni-x W-0. 2N Economical Duplex
           Stainless Steels
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Zi-xing ZHANG , Qing-xuan RAN , Yu-lai XU , Xiao-jiang YU , Da-wei JIANG , Xue-shan XIAO
      A new series of economical Mo-free duplex stainless steels 21. 5Cr-3. 5Ni-x W-0. 2N (x = 1.8 – 3.0, mass%) have been developed. The effects of W on mechanical properties and corrosion resistance were investigated, and the microstructures were analyzed by optical microscopy, X-ray diffraction, transmission electron microscopy and electron backscatter diffraction. The designed steels have a balanced ferrite-austenite relation and are free of sigma phase after solution treatment at 750–1300 °C for 30 min followed by water-quenching, whereas a small number of Cr23 C6 precipitates were found after solution treatment at 750 °C. After solution treatment at 1050 °C, the steel with 1.8% (mass percent) W exhibits the highest room temperature tensile strength due to the strongest work hardening effect, while the steel with 3. 0% (mass percent) W exhibits the highest fracture elongation owing to the transformation-induced plasticity (TRIP) effect. The ductile-brittle transition (DBT) and martensite transformation are respectively found in the ferrite and austenite, which deteriorates the impact properties of the steels with the increase of W content. The corrosion resistance of the designed steels is improved with the increase of W content. The pitting resistance of austenite is obviously better than that of ferrite for the designed alloys. Among the designed steels, the steel with 1.8% (mass percent) W is found to be an optimum steel with excellent comprehensive properties and lowest production cost.


      PubDate: 2014-01-08T04:34:27Z
       
  • Hot Deformation Behavior of As-cast AISI M2 High-speed Steel Containing
           Mischmetal
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Ming-gui QU , Shu-hua SUN , Xing-hong BAI , Zhong-ping SHI , Yang GAO , Wan-tang FU
      The hot deformation behavior of as-cast AISI M2 high-speed steel containing mischmetal (RE) has been investigated on a Gleeble-3500 simulator in the temperature range of 1000–1150 °C and strain rate range of 0. 01 – 10 s−1 at true strain of 1.0. The mechanical behavior has been characterized using stress-strain curve analysis, kinetic analysis, processing maps, etc. Metallographic investigation was performed to evaluate the mechanism of flow instability. The results show that the deformation activation energy decreases with increasing deformation temperature; the efficiency of power dissipation increases with decreasing strain rate and increasing temperature; flow instability is observed at low-to-medium temperature and higher strain rate region when the strain is smaller, but extends to lower strain rate and high temperature regions with the increment of strain, in which it is manifested as flow localization near the grain boundary. Hot deformation equations and processing maps are obtained. The optimal processing window is suggested and the deformation mechanism is dynamic recrystallization (DRX).


      PubDate: 2014-01-08T04:34:27Z
       
  • Influence of Initial Microstructure on Warm Deformation Processability and
           Microstructure of an Ultrahigh Carbon Steel
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Tao WU , Yu-wei GAO , Ming-zhi WANG , Xiao-pu LI , Yu-cheng ZHAO , Qin ZOU
      Various isothermal compression tests are carried out on an ultrahigh carbon steel (1.2% C in mass percent), initially quenched or spheroidized, using a Gleeble-3500 system. The true stress is observed to decrease with increasing temperature and decreasing strain rate. The true stress of the initially quenched steel is lower than that of the initially spheroidized steel at high deformation temperature (700 °C) and low deformation strain rate (0. 001 s−1). The value of the deformation activation energy (Q) of the initially quenched steel (331. 56 kJ/mol) is higher than that of the initially spheroidized steel (297. 94 kJ/mol). The initially quenched steel has lower efficiency of power dissipation and better processability than the initially spheroidized steel. The warm compression promotes the fragmentation and the spheroidization of lamellar cementites in the initially quenched steel. The fragmentation of lamellar cementites is the spheroidizing mechanism of the cementites in the initially quenched steel. Results of transmission electron microscope investigation showed that fine grains with high angle boundaries are obtained by deformation of the initially quenched steel.


      PubDate: 2014-01-08T04:34:27Z
       
  • Corrigendum to “Hot Deformation Behavior of a New 9% Cr Heat
           Resistant Steel G115”
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1




      PubDate: 2014-01-08T04:34:27Z
       
  • Analysis of Gas Thermodynamic Utilization and Reaction Kinetic Mechanism
           in Shaft Furnace
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Zhao-cai WANG , Zheng-gen LIU , Jue TANG , Man-sheng CHU , Xiang-xin XUE
      The technology of coal gasification in shaft furnace is an effective way to develop direct reduction iron in China. In order to clarify the process of the reduction of oxidized pellets in shaft furnace by carbon monoxide or hydrogen in two ways, i. e. thermodynamics and kinetics, the gas utilization and reaction mechanism were studied by theoretical computations and isothermal thermogravimetric experiment. The results showed that the gas utilization increased with the rise of temperature when xH2/x co≥1 and with the increase of x co/(xH2 + x co) when temperature is less than 1073 K. The water-gas shift reaction restrains efficient utilization of gas, particularly in high temperature and hydrogen-rich gas. The gas utilization dropped with increase of carburization quantity of direct reduction iron (DRI) and oxygen potential of atmosphere. With the increase of both temperature and content of H2 in inlet gas, the reaction rate increased. At 100% H2 atmosphere, the interfacial chemical reaction is the dominant reaction restricted step. For the H2-CO mixture atmosphere, the reduction process is controlled by both interfacial chemical reaction and internal diffusion.


      PubDate: 2014-01-08T04:34:27Z
       
  • Metallurgical Interpretation on Grain Refinement and Synergistic Effect of
           Mn and Ti in Ti-microalloyed Strip Produced by TSCR
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Xin-ping MAO , Qi-lin CHEN , Xin-jun SUN
      The grain refinement mechanism and synergistic effect of Mn and Ti involved in the Ti-microalloying technology of thin slab casting and direct rolling (TSCR) were elucidated. Because the inevitable precipitation of TiN in high Ti-containing liquid steel decreases the volume fraction of TiN precipitated from austenite and the rapid coarsening rate leads to a large size of TiN particles, a relatively weak inhibition effect on the recrystallized grain growth was obtained compared with that in the low Ti-containing steel. However, the ferrite grain size in high Ti-containing steel can be refined by the so-called non-recrystallization rolling. The complex addition of Mn and Ti can improve the strength and toughness of strip remarkably, and the mechanisms are that Mn decreases the transformation temperature, refines the ferrite grains, and enhances the formation of bainite and TiC precipitation in ferrite.


      PubDate: 2014-01-08T04:34:27Z
       
  • Mechanism of Strength Improvement of Magnetite Pellet by Adding
           Boron-bearing Iron Concentrate
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Hong-wei GUO , Jun-li BAI , Jian-liang ZHANG , Hong-ge LI
      The mechanism of improving compressive strength of magnetite pellet by adding boron-bearing iron concentrate was studied. Boron-bearing iron concentrate and magnetite were mixed, pelletized and roasted under different roasting conditions. Then, compressive strength of pellets was tested, and polished sections of the roasted pellets were analyzed from the perspective of mineralogy. Finally, the effects of different proportions, roasting temperatures and roasting time of boron-bearing iron concentrate on the compressive strength of magnetite pellets were investigated and explained.


      PubDate: 2014-01-08T04:34:27Z
       
  • Slab Analysis of Large Cylindrical Shell Rolling
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Su-wen CHEN , Hong-min LIU , Yan PENG , Jian-liang SUN
      Considering the characteristics of large cylindrical shell rolling, such as double driving rolls, asymmetrical rolling and huge workpiece, a slab method was developed to establish the rolling force model. In this model, the non-uniform normal and shear stresses and the upper and lower surface temperatures of the workpiece were taken into account. Moreover, the flow stress model, considering the dynamic recovery and dynamic recrystallization behaviors of the material, was established. The rolling pressure distribution, the rolling force, the rolling torque and the neutral points could be calculated quickly and easily by the rolling force model. The predicted results were shown to be in good agreement with the measured values, which indicated that the model can satisfy the requirement of industrial application.


      PubDate: 2014-01-08T04:34:27Z
       
  • Cr Release from Stainless Steels
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Ru-meng WANG , Su-zhen LUO , Lai-zhu JIANG
      Cr release from stainless steels in different simulant fluids according to different test conditions is carried out with emphasis on ferritic stainless steels. Effects of Cr content and surface roughness on Cr release are discussed specially with a relation to corrosion resistant and passive film formation. Some primary results are attained: (1) higher Cr content means better corrosion resistance including higher potential and lower corrosion rate and less amount of Cr release from base metal; (2) decreasing surface roughness is in favor of the formation of passive film which can retrain Cr release from base metal effectively; (3) Cr content and surface roughness have synthetical effects on Cr release with a narrow innoxious field referring to surface roughness with decreasing Cr content in stainless steels.


      PubDate: 2014-01-08T04:34:27Z
       
  • Electrochemical and Mass Loss Investigations of New Schiff Base as
           Corrosion Inhibitor for Mild Steel
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): M. Behpour , N. Mohammadi , E. Alian
      Corrosion inhibition effect of a new compound on mild steel in 6 mol/L HCl medium was investigated by electrochemical impedance spectroscopy, Tafel polarization and mass loss methods. The results of mass loss and electrochemical methods indicated inhibition efficiency increase with increasing in inhibitor concentration. Polarization investigation revealed that inhibitor is mixed type inhibitor. The results of Nyquist plots were analyzed through appropriate equivalent circuit model. The thermodynamic parameters showed chemisorption-physisorption of inhibitor on mild steel surface in acid media.


      PubDate: 2014-01-08T04:34:27Z
       
  • Life Prediction of Newly Developed Ferritic Stainless Steels for
           Automotive Muffler
    • Abstract: Publication date: January 2014
      Source:Journal of Iron and Steel Research, International, Volume 21, Issue 1
      Author(s): Chao CHEN , Yue ZHENG , Yue ZHANG , Xiao-hui LU , Cheng-jia SHANG
      Corrosion mechanism of automotive mufflers was investigated by SEM (scanning electron microscope) and XRD (X-ray diffractomer) analysis. 409L and newly developed 439M steels were evaluated in terms of condensate corrosion tests for 5 periods, 10 periods and 20 periods separately. The relative lifetimes of 409L and 439M steels were predicted according to the extreme value analysis method and pitting corrosion models. Modelling studies demonstrated that the predicted relative lifetime of 439M ferrite stainless steel is 6. 8 times that of 409L steels. The extreme value analysis method was also successfully used in the road test. The estimated maximum corrosion depth of the 439M muffler is 0. 55 mm.


      PubDate: 2014-01-08T04:34:27Z
       
  • Microstructure and Mechanical Properties of Gear Steels After High
           Temperature Carburization
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Yan-hui YANG , Mao-qiu WANG , Jing-chao CHEN , Han DONG
      High temperature carburization is becoming more and more attractive because it can remarkably reduce processing time and increase productivity. However, the commonly used gear steels which are microalloyed by Al are not suitable for high temperature carburization due to abnormal grain coarsening. The gear steel 20CrMnTiNb, which is microalloyed with 0. 048% Nb and 0. 038% Ti, has been compared with the gear steel 20CrMn in terms of microstructure in the case of hardened layer and in the core after carburizing at 1000 °C for 4 h and mechanical properties after carburizing and pseudo-carburizing. The results indicate that the fine austenite grains exist in the carburized case of 20CrMnTiNb steel, while there is abnormal coarsening and duplex grain structure in the case and core of steel 20CrMn. The average prior austenite grain sizes are 19.5 and 34.2 μm for the steels 20CrMnTiNb and 20CrMn, respectively. In addition, the mechanical properties of 20CrMnTiNb steel are superior to those of 20CrMn steel. In particular, the HV hardness of the former is higher than that of the latter by about 40–70 in the range of less than 0.7 mm in depth. Therefore, the steel 20CrMnTiNb is suitable for high temperature carburization.


      PubDate: 2013-12-15T15:06:49Z
       
  • High Temperature Deformation Behavior of 4340 Steel: Activation Energy
           Calculation and Modeling of Flow Response
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): SV Sajadifar , GG Yapici , M Ketabchi , B Bemanizadeh
      The 4340 steel is extensively utilized in several industries including automotive and aerospace for manufacturing a large number of structural components. Due to the importance of thermo-mechanical processing in the production of steels, the dynamic recrystallization (DRX) characteristics of 4340 steel were investigated. Namely, hot compression tests on 4340 steel have been performed in a temperature range of 900–1200 °C and a strain rate range of 0. 01–1 s−1 and the strain of up to 0. 9. The resulting flow stress curves show the occurrence of dynamic recrystallization. The flow stress values decrease with the increase of deformation temperature and the decrease of strain rate. The microstructure of 4340 steel after deformation has been studied and it is suggested that the evolution of DRX grain structures can be accompanied by considerable migration of grain boundaries. The constitutive equations were developed to model the hot deformation behavior. Finally based on the classical stress-dislocation relations and the kinematics of the dynamic recrystallization; the flow stress constitutive equations for the dynamic recovery period and dynamic recrystallization period were derived for 4340 steel, respectively. The validity of the model was demonstrated by demonstrating the experimental data with the numerical results with reasonable agreement.


      PubDate: 2013-12-15T15:06:49Z
       
  • Effects of Welding Procedure on Corrosion Resistance and Hydrogen
           Embrittlement of Supermartensitic Stainless Steel Deposits
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Zappa Sebastián , Surian Estela , Svoboda Hernán
      The effects of shielding gas and post weld heat treatment on the pitting resistance, stress corrosion cracking and hydrogen embrittlement of supermartensitic stainless steel deposits were studied. Two all-weld-metal test coupons were prepared using a metal-cored wire under Ar+5% He and Ar+18%CO2 gas shielding mixtures. Solubilizing and solubilizing plus double tempering heat treatments were done with the objective of achieving different microstructural results. The samples welded under Ar+5% He showed higher pitting corrosion resistance, for all post weld heat treatments, than those welded under Ar+18%CO2. The different post weld heat treatments generated higher susceptibility to this corrosion mechanism. None of the samples presented signs of stress corrosion cracking, but in those subjected to the heat treatment, grain boundary selective attack was observed, on the surfaces of all the samples studied. The samples with highest hardness were more susceptible to hydrogen damage, thereby leading to reduced tensile strength on this condition.


      PubDate: 2013-12-15T15:06:49Z
       
  • Reduction Behaviors of Pellets Under Different Reducing Potentials
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Xiao-jian ZUO , Jing-song WANG , Xiu-wei AN , Xue-feng SHE , Qing-guo XUE
      Owing to the change of gas composition in top gas recycling-oxygen blast furnaces compared with traditional blast furnace, many attentions are attracted to the research on iron oxide reduction again. In order to study the influence of H2 and CO on the reduction behavior of pellets, experiments were conducted with H2-N2, CO-N2 or H2-CO gas mixtures at 1173 K by measuring the mass loss, respectively. It was found that the reduction degree increased with increasing the ratio of H2 or CO in the gas mixture, but the reduction with hydrogen was faster than that with carbon monoxide. The reduction degree could reach 96. 72% after 65 min for the reduction with 50% H2 + 50% N2, while it is only 53. 37% for the reduction with 50% CO+ 50% N2. The addition of hydrogen to carbon monoxide will accelerate the reduction because the hydrogen molecules are more easily chemisorbed and reacted with iron oxide than carbon monoxide. A scanning electron microscope was used to characterize the structures of reduced samples. Dense structure of iron was obtained in the reduction with hydrogen while the structure of iron showed many small fragments for the reduction with carbon monoxide. At the later stage of reduction with the gas mixtures containing carbon monoxide, the reduction curves showed a descending trend because the rate of carbon deposition caused by the thermal decomposition of carbon monoxide was faster than the rate of oxygen loss. Compared with the reduction with CO-N2 and H2-CO gas mixtures, H2 gas could enhance the carbon deposition while N2 gas would reduce this phenomenon. The results of X-ray diffraction and chemical analysis demonstrated that the carbons are mainly in the form of cementite (Fc3C) and graphite in reduced sample.


      PubDate: 2013-12-15T15:06:49Z
       
  • Cold Model Study on Mg Desulfurization of Hot Metal Under Mechanical
           Stirring
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Yan LIU , Zi-mu ZHANG , Jian-nan LIU , Jun-hua ZHANG , Masamichi Sano , Jun ZHANG
      The new method of in-situ desulfurization with mechanical stirring of new type impellers was introduced, in which the bubble's dispersion and disintegration of magnesium vapor were the key to boosting the desulfurization efficiency and increasing the utilization rate of magnesium. Effects of different new type of impellers on bubble dispersion and disintegration were studied through bubble image analysis, gas-liquid mass transfer, and power consumption levels of different impeller structures. The results showed that the sloped swept-back blade impeller-2 produces optimal bubble's dispersion and disintegration, as well as higher volumetric mass transfer coefficient and CO2 gas utilization while consuming the least power. Numerical simulation result with Fluent software also showed that the sloped swept-back blade impeller-2 has higher turbulent kinetic energy and better velocity distribution than the other two impellers.


      PubDate: 2013-12-15T15:06:49Z
       
  • Improvement of Grain Size and Dome Height of Microalloyed Steels Using
           Taguchi Method Based on Grey Relational Grade in Controlled Rolling
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Mohsen Ayaz , Daavood Mirahmadi Khaki , Nasrollah Bani Mostafa Arab
      An efficient approach was introduced for improving the condition of major controlled rolling process parameters of roughing, finishing and coiling temperatures and optimizing these parameters to obtain minimum grain size and maximum dome height simultaneously. Taguchi method combined with grey relational analysis was applied to achieve optimum grain size and dome height during controlled rolling process. For this purpose, four levels for the above temperatures were chosen and sixteen experiments were conducted based on orthogonal array of Taguchi method. Based on Taguchi approach, signal-to-noise (S/N) ratios were calculated and used in order to obtain the optimum levels for every input parameter. Analysis of variance revealed that finishing and coiling temperatures have the maximum effect on the grain size and dome height of microalloyed steels. The confirmation tests with the optimal levels of parameters indicated that the grain size and dome height of controlled rolled microalloyed steels can be improved effectively through this approach.


      PubDate: 2013-12-15T15:06:49Z
       
  • Influence of Cast Dimension on Rotary Bending High Cycle Fatigue
           Properties of Single Crystal Superalloy
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Zhen-xue SHI , Mei HAN , Shi-zhong LIU , Jia-rong LI
      Samples of DD3 single crystal superalloy with different dimensions were cast in the directionally solidified furnace with high temperature gradient. The effect of cast dimension on the rotary bending high cycle fatigue (HCF) properties of the alloy was investigated at 800 °C in ambient atmosphere. SEM was used to examine the fracture surface and fracture mechanism of the alloy. The results show that the rotary bending HCF properties of the alloy decreases with increasing cast dimension. The cast dimension has little effect on the HCF fracture mechanism of the alloy. The HCF fracture mechanism of the alloy with different cast dimensions is all quasi-cleavage fracture. The fatigue cracks initiated on the surface or near the surface of the specimens. The crack would propagate along {111} octahedral slip planes. Typical fatigue arc and striation formed on fatigue crack steady propagation. The degeneration of HCF properties is due to the increase of dendrite arm spacing and size of γ′ phase particles and maximal microporosity.


      PubDate: 2013-12-15T15:06:49Z
       
  • Determination of Two-Dimensional Plastic Zone Shape and SIF at Crack-Tip
           Using RKPM
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Masood Hajali , Caesar Abishdid
      Reproducing kernel particle Method (RKPM) is a meshless technology which has proven very useful for solving problems of elastic-plastic fracture mechanics. The mode I plastic zone shape at the crack-tip in a work-hardening material is obtained using RKPM. Ramberg-Osgood stress-strain relation is assumed and the crack-tip stress intensity factor (SIF) before and after formation of the plastic zone are examined. To impose the essential boundary conditions, penalty method is used. To construct the shape functions in the vicinity of the crack and crack-tip, both the diffraction and visibility criteria are employed. A comparison between two conventional treatments, visibility and diffraction, to crack discontinuity is conducted. The effects of different dilation parameters on SIF under plane-stress and plane-strain conditions are studied. Results including plastic zone shape are compared with finite element method (FEM) to show the accuracy of RKPM. The main objective is to study the effects of different dilation parameters on SIF under plane stress and plane strain conditions and to obtain the mode I plastic zone shape at the crack-tip in a work-hardening material using RKPM.


      PubDate: 2013-12-15T15:06:49Z
       
  • Control of Hydrogen During ESR Process
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Chen YAN , Ying LI , Bei-yue MA
      Experimental and numerical studies were carried out for the behavior of hydrogen in a three-phase electroslag furnace using double electrode series technique during electroslag remelting (ESR) process. The effect of water vapor content of furnace gas on the hydrogen content of ingots was studied through the “gas-slag-metal” osmosis experiment. Based on the experimental results, a mathematical model was set up for the behavior of hydrogen pick-up during ESR process. Then the flow of furnace gas during ESR process was studied through a commercial code FLUENT, and the relationship between the water vapor content of furnace gas and argon gas flux in practical production was derived. Finally, the desired reasonable argon gas flow for controlling the hydrogen content of ingots below 2×10−6 in practice was obtained.


      PubDate: 2013-12-15T15:06:49Z
       
  • Influence of Hydrogen on GBF in Very High Cycle Fatigue of High Strength
           Steel
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Chao ZHOU , Yong-jian ZHANG , Wei-jun HUI , Lei WANG
      The relationship of hydrogen, GBF (granular bright facet) and very high cycle fatigue properties of high strength spring steels 60Si2CrV with three different hydrogen contents were studied using hydrogen thermal desorption analysis and ultrasonic fatigue test. The results showed that the influence of hydrogen on the relationship between fatigue life and the ratio of GBF to inclusion size ( A GBF A INC ) was obvious, and the expression between fatigue life and A GBF A INC with different hydrogen contents can also be obtained. In addition, based on the research of hydrogen diffusion and GBF, it was explained why the GBF cannot form below 106 cycles. At last, the estimated critical fatigue life of GBF formation can be expressed accurately.


      PubDate: 2013-12-15T15:06:49Z
       
  • Effect of Hardfaced Interlayer Thickness and Low Hydrogen Ferritic Capping
           
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): M Balakrishnan , V Balasubramanian , G Madhusudhan Reddy
      Armour grade quenched and tempered steel closely confirming to AISI 4340 is well known for its superior ballistic performance and hence used in the fabrication of combat vehicles. The traditional fillers like austenitic stainless steel showed poor ballistic performance of these welded joints as compared to the base metal. Attempts have been made to deposit hardfaced interlayer between austenitic stainless steel weld metals. Though this method, marginal improvements in ballistic performance can be yielded, and cracks were observed in between base metal and hardfaced layer. Thickness of the hardfaced interlayer plays a vital role for the effective ballistic performance. Thus, an attempt has been made to investigate the effect of hardfaced interlayer thickness on ballistic performance of armour steel welds. The results of effect of buttering, low hydrogen ferritic (LHF) filler and three different hardfaced layer thicknesses (4, 5.5 and 7 mm) on ballistic performance of shielded metal arc welded armour steel joints were given.


      PubDate: 2013-12-15T15:06:49Z
       
  • A Comparison Study on Corrosion Resistance of 430 Stainless Steel Surfaces
           Modified by Alkylsilane and Fluoroalkylsilane SAMs
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Hai-ren WANG , Zhen XIAO , Jun-e QU , Hong-wei YANG , Zhi-yong CAO , Xing-peng GUO
      The self-assembly monolayers (SAMs) of n-dodecyltriethoxysilane (DTES) and 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (PFDS) on the surface of the 430 stainless steel (430SS) were prepared and their corrosion protection performance was investigated by potentiodynamic polarization, Fourier transform infrared spectroscopy (FTIR) -attenuated total reflection (ATR), static contact angle and atomic force microscopy (AFM). The results showed that the alkali pretreatment and the water added into the self-assembly solution could generate more hydroxyls on the 430SS surface, and then enhanced the adsorption of the SAMs. A suitable temperature of the self-assembly solution is important for the formation of the SAMs. The silane SAMs were chemically adsorbed on the 430SS substrates by Fe-O-Si bonds. In all cases tested, PFDS has a better inhibition effect compared with DTES, and the difference in inhibition effect is most marked at the lowest concentration of 1 mmol/L.


      PubDate: 2013-12-15T15:06:49Z
       
  • Flow Behavior and Numerical Simulation of Spray-Formed FGH95 Superalloy
           Under Hot Compression
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Biao GUO , Chang-chun GE , Yi XU
      The flow behavior of spray-formed FGH95 superalloy (similar to Rene 95) was investigated at temperatures ranging from 1050 to 1140 °C and strain rate ranging from 0. 01 to 10 s−1. At a given temperature and strain rate, flow stress increases quickly with increasing strain and then reaches a peak, then gradual decreases until high strain, and dynamic softening is observed. Utilizing the hyperbolic sine function and introducing the strain with nonlinear fitting, the revised constitutive equations incorporating the effects of temperature, strain rate and strain for high temperature flow stress prediction of superalloy were established. The revised constitutive equations were implanted into finite element software by second development to simulate the hot compression process successfully, and the effective stress and load stroke curves obtained by numerical simulation are good agreement with the experimental results.


      PubDate: 2013-12-15T15:06:49Z
       
  • Effect of Nb on Mechanical Properties of HAZ for High-Nb X80 Pipeline
           Steels
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Xiao-wei CHEN , Bo LIAO , Gui-ying QIAO , Yu GU , Xu WANG , Fu-ren XIAO
      The mechanical properties of heat affected zone (HAZ) of two commercial high-Nb X80 grade pipeline steels with different alloy elements were investigated using thermal simulation performed on a Gleeble-3500 thermal simulator. The results showed that the high-Nb steels have excellent weldability. Embrittlement regions appear in coarse grain heat affected zone (CGHAZ) and intercritically heat affected zone (ICHAZ); Softening region appears in fine-grain heat affected zone (FGHAZ), and the strength here was even lower than 555 MPa as required in the standard. Meanwhile, with the increase of heat input, the strength and the toughness of HAZ of steel with high Nb, C and lower alloy decrease notably. Therefore, take into account the welding procedure during manufacture of weld pipe, suitable amount of alloy elements, such as Cr, Ni, Cu, Mo and so on, is necessary for high Nb X80 heavy-thick steel plate.


      PubDate: 2013-12-15T15:06:49Z
       
  • Precipitation Behavior and Textural Evolution of Cold-Rolled High Strength
           Deep Drawing Dual-Phase Steels
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Zhi-gang WANG , Ai-min ZHAO , Zheng-zhi ZHAO , Jie-yun YE , Jing-jing CHEN , Jian-guo HE
      Low-carbon Cr-Mo micro-alloyed deep drawing dual-phase steels were designed in laboratory. As the microstructure and texture evolution in hot-rolled strips and annealed sheets were investigated using SEM, TEM and XRD technologies, the attribution of solute Mo and MoC particles to DP sheets' drawing capacity was investigated. The precipitation thermodynamics were also calculated by Thermo-calc software. Results show that the precipitates in hot-rolled strips mainly are MoC, AlN and MnS, and with the increase of Mo-addition, finer and denser MoC particles precipitated in matrix and along grain boundaries of ferrite more easily. Weak textures are shown in the hot-rolled strips, and {112}<110> and {223}<110> components tend to be stable in subsequent cold rolling process. During annealing, on one hand, the development of <111> // ND texture is suppressed because finer MoC particles prevent the grain boundary migration. On the other hand, unfavorable texture {001}<110> significantly reduces with Mo increasing, which is attributed to that part of solution C in matrix has been fixed during recrystallization. In addition, the addition of Mo can enhance hardenability strongly and MoC easily re-dissolve at high temperature, which is favor to form martensite in dual-phase steel.


      PubDate: 2013-12-15T15:06:49Z
       
  • Microtexture Evolution and Grain Boundary Character Distribution of
           Interstitial-Free Steels With Moderate Levels of Cold Rolling Reductions
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Jing-jing YANG , Li-xia FAN , Juan JIA , Run WU , Xin-li SONG , Li-li JIANG
      High-strength interstitial-free steel sheets have very good deep drawability when processed to have {111} recrystallization texture. The microtexture evolution and grain boundary character distribution of interstitial-free steels as a function of moderate levels of cold rolling reductions were investigated by the metallographic microscopy and electron backscatter diffraction technique. The results showed that there was a close relationship between microtexture and grain boundary character distribution for interstitial-free steel, especially the distribution and features of some specific types of coincident-site lattice boundaries. In addition, α-fiber texture was weakened to vanish while γ-fiber texture strengthened gradually as cold rolling reduction was increased from 20% to 75% for cold rolled and annealed samples. Accordingly, increasing the rolling reduction from 20% to 75% would lead to a significant increase in the proportion of Σ3 boundaries. Also, it was found that the microtexture of 20% cold rolled sample would induce a high frequency of Σ11 grain boundaries, but the microtexture of 75% cold rolled sample would produce more Σ7 and Σ17 grain boundaries. It was suggested that texture played a significant role in the formation of grain boundary character distribution.


      PubDate: 2013-12-15T15:06:49Z
       
  • Real-Time Slab Quality Diagnosis and Analysis System Based on
           Solidification Mechanism
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Ke FENG , Shui-gen WANG , Zhi-wei HAN , Yi-wen KONG , Jian-feng CAO
      According to the two types of slab defects (surface crack and internal crack), a real-time slab quality diagnosis and analysis system named CISDI_SQDS ONLINE R2011 was developed based on heat transfer and solidification simulation, stress and strain calculation as well as metallurgical process analysis about continuous casting, combined with expert knowledge database for specific casting events. The respective crack formation indexes were introduced as the theoretical reference data for slab quality level evaluation. Meanwhile, both the quality loss factors related to casting metallurgical rules and the adjusting factors related to casting events were taken into full consideration, which was integrated organically with theoretical analysis and expert system. The system can be widely used as an important theoretical tool for prediction and control of slab quality in slab continuous casting process.


      PubDate: 2013-12-15T15:06:49Z
       
  • Development and Experimental Evaluation of Strip Shape Prediction Model
           for Sendzimir Rolling Mills
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Jong-min SHIN , Seong-ik HAN , Jong-shik KIM
      It is difficult to obtain the desired strip shape using Sendzimir rolling mills because small diameter work rolls can be easily deformed by the rolling force. To control the strip shape effectively, it is important to understand the relationship between the behavior of the shape actuator and the variation of the strip shape. A numerical model based on the contact element method was proposed for the prediction of strip shape. In this numerical model, the relationships between the actuating forces, the roll deflections, the thickness profiles of the entry and exit sides, and the strip shape were considered. The proposed numerical model for strip shape prediction was evaluated by computer simulation and experiment with respect to various AS-U roll and first intermediate roll positions.


      PubDate: 2013-12-15T15:06:49Z
       
  • Effect of Chute Rotation on Particles Movement for Bell-less Top Blast
           Furnace
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Zhao-jie TENG , Shu-sen CHENG , Guo-lei ZHAO , Peng-yu DU
      For the bell-less top blast furnace, when particles move along the chute, the particles motion direction and the frictional force acting on them will change due to the chute rotation, which consequently influences the velocity at the tip of chute, changes the burden flow width and impact point, and finally affects the stock profile and gas flow distribution. So the influence of chute rotation needs to be considered when calculating the burden trajectory with a mathematical model. The mathematical model was established to analyze the influence of Coriolis force on particle velocity at chute tip as well as height and width of burden flow in chute, and to summarize the effect of Coriolis force on burden distribution, thereby making the calculation result more accurate.


      PubDate: 2013-12-15T15:06:49Z
       
  • Investigation and Application of Non-sinusoidal Oscillation Technique of
           Mold
    • Abstract: Publication date: December 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 12
      Author(s): Xing-zhong ZHANG , Xue-ran ZHENG , Qing-guo LIU , Xian-kui LI , Yi-ming FANG
      To improve the slab quality, a kind of non-sinusoidal oscillation technique of mold driven by elliptic gears was developed. The waveform functions of non-sinusoidal oscillation were determined, and the calculation method and curves of technological parameters for non-sinusoidal oscillation were given. At the case of waveform deviation factor α equal to 0. 31 and oscillation amplitude h equal to ±2.7 mm, the relationship between oscillation frequency and casting speed is determined, and the technological parameters for non-sinusoidal oscillation are calculated. The testing results of industrial application indicated that this technique could not only improve the slab surface quality, but also reduce the steel breakout.


      PubDate: 2013-12-15T15:06:49Z
       
  • Optimization Evaluation Test of Strength and Toughness Parameters for
           Hot-Stamped High Strength Steels
    • Abstract: Publication date: November 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 11
      Author(s): Liang YING , Jin-dong LU , Ying CHANG , Xing-hui TANG , Ping HU , Kun-min ZHAO
      Use of hot-stamped high strength steels (HSHSS) not only reduces the vehicle weight, but also improves the crash safety, therefore more and more mentioned steels are used to produce automobile parts. However, there are several problems especially the low ductility and toughness, which have restricted the application of HSHSS in automobile body. Suitable process parameters are very crucial to improve strength and toughness. In order to study the effect of austenization temperature, soaking time and start deformation temperature on strength and toughness of boron steel 22MnB5, an L9 (34) orthogonal experiment which was analyzed by means of comprehensive evaluation was carried out based on Kahn tear method to obtain the value of fracture toughness. The results indicate that the excellent formability, high strength and toughness of boron steel 22MnB5 with 1.6 mm in thickness are obtained when the austenization temperature is in the range of 920 — 950 °C, the soaking time is 1 min and the start deformation temperature is in the range of 650 — 700 °C. The optimal parameters were used for typical hot stamping structural parts tests. Properties of samples such as tear strength, unit initiation energy and ratio of strength to toughness (RST) were improved by 10.91%, 20.32% and 22.17%, respectively. Toughness was increased substantially on the basis of a small decrease of strength.


      PubDate: 2013-11-13T04:34:16Z
       
  • Activity Calculation Model for Ternary Slag System of Al2O3-BaO-B2O3
    • Abstract: Publication date: November 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 11
      Author(s): Jian ZHOU , Qiang WANG , Zhe QIN , Sheng-tao QIU , Yong GAN , Guo-ling ZHU
      According to the ion and molecule coexistence theory, the activity model of Al2O3-BaO-B2O3 ternary slag system was established, and the influences of BaO/Al2O3 molar ratio, B2O3 mole fraction and temperature on the activity of the slag system were investigated. Finally, the equal activity curves were drawn with the model results. The results show that with the increase of BaO/Al2O3 ratio, the activity of Al2O3 is significantly reduced, the activity of BaO • Al2O3 is increased obviously, and the activity of 2Al2O3 • B2O3 is also decreased. With the increase of B2O3 mole fraction, the activity of BaO • Al2O3 decreased significantly, while the activities of BaO • 2B2O3 and 2Al2O3 • B2O3 increased. In addition, the influence of temperature on the activities of different components is comparatively smaller than the influence of BaO/Al2O3 ratio and B2O3 mole fraction.


      PubDate: 2013-11-13T04:34:16Z
       
  • Comparison and Optimization of Mid-low Temperature Cogeneration Systems
           for Flue Gas in Iron and Steel Plants
    • Abstract: Publication date: November 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 11
      Author(s): Li-hua ZHANG , Li-jun WU , Xiao-hong ZHANG , Gui-dong JU
      Three generation systems, namely, steam Rankine cycle (SRC), organic Rankine cycle (ORC), and steam-organic combined Rankine cycle (S-ORC), were simulated using the Engineering Equation Solver (EES) to efficiently utilize flue gas emissions from 200 to 450 °C in iron and steel plants. Based on the simulation results for thermal efficiency, exergy efficiency, and power generation, the performances of the three power generation systems were compared and analyzed. To further utilize waste heat from the turbine exhaust steam of the ORC system, cascade ORC (CORC) was designed for heat sources above 300 °C. Based on a comprehensive performance comparison, the application of the ORC using R141 b is preferable for 200 to 300 °C flue gas. For 300 to 450 °C flue gas, CORC is an alternative technology to improve the efficiency and quality of waste heat utilization. For flue gas above 450 °C, S-ORC can achieve higher efficiency and power generation than conventional SRC, with a relatively small negative pressure and high dryness of the turbine outlet steam. Hence, S-ORC can be considered as a substitute for SRC.


      PubDate: 2013-11-13T04:34:16Z
       
  • Numerical Simulation and Experimental Study on Interlock Deformation for
           Roll Formed U-Section Steel Piling
    • Abstract: Publication date: November 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 11
      Author(s): Guang-hong FENG , Pei ZHANG , Hong-liang ZHANG , Xu-chang ZHOU , Yong ZHAO
      The interlock of a roll formed U-section sheet steel piling under loading was analyzed by means of numerical simulation, and meanwhile the tensile failure experiment was conducted. The results indicated that under the same load, the interlock corners of roll formed steel piling are not only the regions with the lowest safety factor, but also the regions with the highest stress; there are two slippages in the tensile instability process of interlock. Each slippage can be regarded as a failure, and different types of failure mode should be used to evaluate the performance of steel pilings according to different applications. Due to the work hardening effect during the roll forming process, the hardness of the interlock material increases by 16% compared with that of the original sheet steel. It was also found that the instability strength obtained in tensile failure test is only 15.6% of the tensile strength of the original sheet steel.


      PubDate: 2013-11-13T04:34:16Z
       
  • Correlation Between Radial Growth Rate of Cylindrical Solid and Time in
           Melt
    • Abstract: Publication date: November 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 11
      Author(s): Shu-ying CHEN , Guo-wei CHANG , Xu-dong YUE , Qing-chun LI , Guang-can JIN
      The radial growth of δ-phase in Fe-0.15%C-0.8% Mn steel during solidification was in-situ observed under a high-temperature confocal scanning laser microscope (HTCSLM). The correlation between radial growth rate of cylindrical solid and time in melt was investigated, and the expression was deduced. The results indicate that the radius of cellular δ-phase rapidly enlarges at the beginning, and then the enlargement amplitude gradually declines. The variation of radial growth rate vs time is the same for each cellular δ-phase, and the radial growth rate of δ-phase rapidly declines to about 1.5 μm/s within 10 s at a cooling rate of 2.7 K/min, after that the growth rate slowly falls. The experimental data of the radial growth rate of cellular δ-phase are consistent with the calculation results for Fe-0.15%C-0.8% Mn steel.


      PubDate: 2013-11-13T04:34:16Z
       
  • Effects of Transition Metal Oxides on Thermal Conductivity of Mould Fluxes
    • Abstract: Publication date: November 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 11
      Author(s): Xin QIU , Bing XIE , Xue-mei QING , Jiang DIAO , Qing-yun HUANG , Shui-bo WANG
      The thermal conductivity of the mould fluxes containing transition metal oxides was measured by hotline method at different temperatures. The relationship between the thermal conductivity of mold fluxes and the contents of transition metal oxides was discussed. The synthetic slags were composed of 30.0% — 35.4% CaO, 34.7% — 38.6% SiO2, 6% Al2O3, 9% Na2O, 14.4% CaF2, 0–4% Cr2O3 and 0–8% MnO in mass percent. The results indicated that Cr2O3 and MnO had a negative effect on thermal conductivity of mold fluxes. The thermal conductivity of mold fluxes was about 0.25 — 0.55 W/(m K) when the temperature reached 1300 °C, and it increased sharply to about 1.32–1.99 W/(m K) when the temperature reduced from 1300 to 1000 °C. The thermal conductivity of mold fluxes containing Cr2O3 and MnO was 10%—25% lower than those of original fluxes. The decrease in thermal conductivity was attributed to the change of molecular structure of mold fluxes. In addition, the poor integrity and regulation of polycrystal structure, complexity of crystal structure, and effects of impurities in the boundary and lattice distortion leaded to the reduction in the thermal conductivity. Na2CrO4, Mn2SiO4 and other minor phases were also found in the samples containing Cr2O3 and MnO, respectively.


      PubDate: 2013-11-13T04:34:16Z
       
  • Permissible Minimum Thickness in Asymmetrical Cold Rolling
    • Abstract: Publication date: November 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 11
      Author(s): De-lin TANG , Xiang-hua LIU , Xiang-yu LI , Liang-gui PENG
      The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling force equation by slab method. An implicit expression of the minimum rolling thickness was then derived from the rolling force equation and Hitchcock equation. The results show that permissible minimum rolling thickness of asymmetrical rolling only exists within a specific range of cross-shear ratio, which is termed the cross-shear zone proportion of the whole deformation zone. Numerical computation was carried out to obtain a discrete solution of the minimum rolling thickness. Experiments were designed to investigate the influence factors on cross-shear ratio. Finally, experimental results prove the correctness of the improved formula given.


      PubDate: 2013-11-13T04:34:16Z
       
  • Numerical Simulation of Fractal Agglomerating-Growth of Al2O3 Inclusions
           in Tundish
    • Abstract: Publication date: November 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 11
      Author(s): Luo-fang GUO , Hong LI , Hai-tao LING , Yao WANG , Wen-chen SONG
      Based on the Al2O3 inclusion analysis of low-carbon aluminum killed steel in tundish of a domestic steel company and fractal theory analysis, a mathematical model of fractal agglomerating-growth of Al2O3 inclusions in tundish was established. The results indicated that: large swirl flows exist in both sides of inlet, space between weir and dam, and large zone above outlet, in which monomer and agglomerated inclusion particles accumulate easily; the agglomerated inclusions with hydrodynamic diameter of 6 — 9.8 μm were quickly generated less than 16 s, but those inclusions with hydrodynamic diameter more than 11 μm were difficult to form; the number density of agglomerated inclusion rapidly increased first, then slowly reduced, so the form and quantity distribution of agglomerated inclusions can be controlled by controlling the residence time of inclusion particles in tundish.


      PubDate: 2013-11-13T04:34:16Z
       
  • Control of Macrosegregation Behavior by Applying Final Electromagnetic
           Stirring for Continuously Cast High Carbon Steel Billet
    • Abstract: Publication date: November 2013
      Source:Journal of Iron and Steel Research, International, Volume 20, Issue 11
      Author(s): Chao XIAO , Jiong-ming ZHANG , Yan-zhao LUO , Xiao-dong WEI , Lian WU , Shun-xi WANG
      Solidification behavior of continuously cast high carbon steel billets was investigated with an objective of producing high quality billets by determining the optimum final electromagnetic stirring (F-EMS) parameters. Characteristics of centerline segregation were analyzed for lots of billet samples collected from the plant through obtaining the carbon concentrations of drill chips, which were correlated with the operating parameters of the caster and stirrers, but a problem occurred that segregation control results of trial billets with the same casting and stirring parameters often have drastic fluctuations. An attempt was made to find out the induced reasons of this problem by measuring the electromagnetic torque, analyzing the secondary dendrite arm spacing (SDAS) and the corresponding cooling rate of the typical specimens, and observing the longitudinal profile of etched billet samples. Then a simple dynamic secondary cooling model was developed based on the solidified shell thickness control mode, by which the maximum carbon segregation index was reduced effectively, and thus the segregation fluctuation problem was basically solved. Finally, the most favourable stirring parameters were determined as the casting speed of 1.65 m/min, the liquid core thickness of 40 mm, stirring current of 360 A and frequency of 12 Hz.


      PubDate: 2013-11-13T04:34:16Z
       
 
 
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