IRON AND STEEL

钢铁

Home | About Journal | Editorial Board | Instruction for Authors | Subscriptions | Advertisement | Contacts Us | Chinese

　

Office Online

　

　

　

　

　

　

Editor-in-chief

　

Journal Online

　

　

Forthcoming Articles

　

　

　

　

Download Articles

　

　

Quick Search

Advanced Search

	2012 Vol. 47 No. 2
	Published: 2012-02-15



	Steelmaking Metal Forming Materials Environmental Protection and Energy

Raw Materials and Ironmaking

	7	LIU Ran1,GAO Yong-liang1,WANG Xing-juan1,L Qing1,DU Lin-sen2,WANG Zhu-min2
		Flash Pyrolysis of Pulverized Injection Coal at Handan Steel Co
		Aimed at increasing pulverized coal injection at Handan Steel, the pyrolysis of coal in raceway was simulated. The coal of CL and DW were selected and the decomposition rate was calculated by plasma pyrolysis. Gas products were analyzed by gas chromatography and morphology of residues were observed by scanning electron microscopy (SEM). The results show that CL and DW decomposition rate is 43.10% and 52.04% respectively and gas products of coal after plasma pyrolysis, which are different from general pyrolysis, consist of CO, H2, CH4, C2H2 and small content of C2H4, etc. Pyrolysis product has changed evidently, particle size become smaller. The vesicular structure occurs in coal grains when DW is added in the sample, which makes the specific surface area of coal grain increase. The solid carbon combustion ratio in tuyeres can be enhanced, which will provide the theoretical basis for pulverized coal combustion rate.
		2012 Vol. 47 (2): 7-11 [Abstract] ( 2555 ) [HTML 0KB] [PDF 0KB] ( 58 )

	12	CHEN Yong-xing,WANG Guang-wei,ZHANG Jian-liang,SU Bu-xin,ZUO Hai-bin
		Theoretical Analysis of Injecting Coke Oven Gas With Oxygen Enriched Into Blast Furnace
		The changes of indirect reduction rate, coke rate, blast volume, bosh gas volume, adiabatic combustion temperature of the raceway and composition of blast furnace gas were simulated by computer. In the meanwhile the effect of changing oxygen enrichment and coke oven gas (COG) injection rate was studied. The results show that on condition of adequate heat and proper adiabatic combustion temperature, suitable oxygen enrichment and coke oven gas injection can make coke rate reduced to 291kg/t, carbon dioxide emission reduced by 6.1%, blast furnace gas utilization improved, and lead to better economic and environmental benefits.
		2012 Vol. 47 (2): 12-16 [Abstract] ( 2769 ) [HTML 0KB] [PDF 0KB] ( 55 )

	17	ZHANG Li-guo，WANG Zai-yi，ZHANG Hong-yu，ZHANG Wei
		Industrial Practice of Pulverized Coal Injection With Combustion Supporting Agent for New No.5 BF in Ansteel
		The industrial practice of pulverized coal injection with combustion-supporting agent in the No.5 blast furnace of Ansteel was carried out, and the goal was to get the effect of Mn series combustion-supporting agent on pulverized coal injection. The dailly production of hot metal with 0.4%-0.6% combustion agent grew up 435.6t compared with the index without combustion agent, coke rate decreased 10.3kg/t hot metal, the coal injection improved 8.1kg/t hot metal, the CO2 proportion in gas decreased 0.69%, and the average combustion efficiency reached 4593% which was 6.06% higher than traditional operation.
		2012 Vol. 47 (2): 17-21 [Abstract] ( 2752 ) [HTML 0KB] [PDF 0KB] ( 71 )

Steelmaking

	22	AI Li-xiang1,2,WANG Hong-bing3,XU An-jun1,2,TIAN Nai-yuan1,2,HE Dong-feng1,2
		Efficient Smelting Model of AOD Furnace Steelmaking
		The research on traditional AOD efficient smelting was focused on enhancement of oxygen supply, optimization of improving volume ratio, increasing end hitting rate. Current device should be made full of, and AOD charging structure and oxygen supply should be optimized. Process parameters of AOD should be optimized. Physical heat and chemical heat should be rational used, and efficient smelting of AOD should be realized. Based on mass balance model and energy balance model, the model of AOD efficient smelting was proposed considering process features of AOD steelmaking. The change of tap to tap time with hot metal ratio and scrap steel ratio was simulated. The charging structure was got when tap to tap time was the shortest. The results indicate that the tap to tap time increases with molten iron ratio increasing in AOD steelmaking process with EAF stainless molten iron and BF molten iron. The tap to tap time increases with scrap steel ratio increasing in AOD steelmaking process with EAF stainless molten iron and scrap steel. The tap to tap time increases with scrap steel ratio increasing in AOD steelmaking process with BF molten iron and scrap steel. The tap to tap time with ferrosilicon heating agent is shorter than the time with carbon powder heating agent.
		2012 Vol. 47 (2): 22-25 [Abstract] ( 2799 ) [HTML 0KB] [PDF 0KB] ( 51 )

	26	YANG Jun,SHENG Jian-hua,LU Li-jun,GU Xue-hong
		Development and Application of Mould Powder for Continuous Casting Slab of Martensitic Stainless Steel
		Due to the metallographic characteristics of the martensitic stainless steel, longitudinal crack was easily generated at wide-face and corner of slab during solidification process, which would seriously affect the production and grinding machine operating rate. Meanwhile, the slab quality was not improved owing to general mould flux in martensitic stainless steel. The design principle of mould powder with high basicity, low viscosity and high crystallinity was decided through study the relationship between basicity and CaF content of mould powder and the properties of viscosity and crystallinity. The domestic martensitic stainless steel slab mold flux was developed. As a result, and the degree of longitudinal crack was decreased by 30%.
		2012 Vol. 47 (2): 26-29 [Abstract] ( 2339 ) [HTML 0KB] [PDF 0KB] ( 92 )

	30	CHEN Liang1,CHEN Tian-ming1,ZENG Jian-hua1,FENG Yuan-chao1,YANG Seng-xiang2,YANG Hong-bo2
		Improving Pourability of Molten Steel for Square and Round Billet Continuous Caster
		To solve the problems of nozzle clogging and low continuous casting numbers of the billet and round continuous casting machine in Vanadium Recovery and Steelmaking Plant of Pangang, the steelmaking process was optimized, such as raising the content of carbon in molten steel, optimizing the deoxidation process, promoting the inclusions floatation with effective measures, promoting diffusive deoxidation of molten steel. The industrial practice shows that w(［Ca］)/w(［Al］) in tundish molten steel can be controlled in the range of 0.05-0.15, and w(［Ca］)/w(［S］) can be controlled in 0.15 more or less as well. With these countermeasures, the pourability can be improved obviously. Furthermore, the problem of nozzle clogging can be solved basically, and it can continuously cast 8 heats from below 5 heats in single tundish.
		2012 Vol. 47 (2): 30-33 [Abstract] ( 2543 ) [HTML 0KB] [PDF 0KB] ( 56 )

	34	XIANG Chang-xiang,WANG Li-jun
		A New Model of Selective Oxidation During Blowing Low-Silicon Hot Metal
		In order to understand the essence of problems occurred in blowing low-silicon hot metal, the Gibbs energies of oxidation of ［C］ and ［Si］ were calculated at different ［Si］ concentration. A new concept of “oxidation transfer concentration” was proposed, which can indicate the critical point of selective oxidation of ［Si］ or ［C］ in hot metal. On the basis of this new concept, the influence of low silicon hot metal on steelmaking process was discussed, and the optimal ［Si］ concentration in low silicon hot metal was given. Furthermore, effect of ［C］ concentration on this “oxidation transfer concentration” of ［Si］ was also analyzed and formulated, which can be used to evaluate the oxidation transfer concentration in various conditions. Thus, it will be flexible to perform operation accordingly in practice.
		2012 Vol. 47 (2): 34-38 [Abstract] ( 2531 ) [HTML 0KB] [PDF 0KB] ( 64 )

	39	LI Yong1,3,WU Wei2,ZHU Qi-zhu3,WEI Zhi-qiang3
		Quality and Complex Performance of Deformed Steel Bars by the Whole Process Bottom Blowing Nitrogen of BOF
		Base on the research results of literatures and production condition of BOF, the influences of the smelting process by whole process bottom blowing nitrogen on the quality and complex performance of rolled metal were systematically investigated in the combined blown converter. Through adopting the process of whole process bottom blowing nitrogen and the change-over from nitrogen to Ar (including Ⅰand Ⅱmode), the nitrogen and oxygen content in steel during the refining, casting, the casting blank and rolled metal quality and the complex performance of rolled metal were studied. The results show that the nitrogen content, the inclusion and metallurgical structure grades, the yield strength, tensile strength and percentage elongation after fracture of rolled metal produced by whole process bottom blowing nitrogen and the change-over from nitrogen to Ar have no distinctly difference. However, for same supply gas mode, different supply parameters, there are certain influences on above results. Meanwhile the influence factors of ageing on complex performance of rolled metal were studied.
		2012 Vol. 47 (2): 39-43 [Abstract] ( 2294 ) [HTML 0KB] [PDF 0KB] ( 46 )

	44	KONG Xiang-tao1,ZHOU De1,CHEN Hong2,ZHANG Bao-quan2,WANG Li-feng1
		Analysis of Broken Reasons for Wire of Big-Size and High Strengh SWRH82B During Drawed Process
		Shougang’s big-size and high strength SWRH82B was broken during drawed process, which had relation with broken corner, subcutaneous crack of billet and wire of micro-section cellular structure. The intensity of cooling was improved for mold and secondary cooling by seasonal temperature. The product quality can meet requirements of bloom through adjusting cooling water of mold, regulating the secondary cooling water distribution, changing suitable characteristic mold powder, adopting catch carbon of finish point with micro-nitrogen carburant in converter.
		2012 Vol. 47 (2): 44-48 [Abstract] ( 2227 ) [HTML 0KB] [PDF 0KB] ( 61 )

Metal Forming

	49	SUN Jing-na,XUE Tao,DU Feng-shan
		FEM Analysis of Contact Stress and Crown Control for Six-High CVC Mill
		In order to study the crown control of six-high CVC mill, using nonlinear elastic-plastic finite element method, a 3D FE simulation model of six-high CVC rolling process was developed with the nonlinear FE software MSC.MARC. In the model, the elastic deformation of rolls and the elastic-plastic deformation of workpiece were coupled as a whole. Based on the model, the changes of work roll bending force, intermediate roll bending force, intermediate roll transverse shifting were simulated. The influence rules of the contact stress and crown control were obtained. The model and the calculated results can offer theoretic data and reference frame to establish the shape control model for six-high CVC mill.
		2012 Vol. 47 (2): 49-52 [Abstract] ( 2666 ) [HTML 0KB] [PDF 0KB] ( 52 )

	53	HOU Hua-xing1,YANG Ying1,ZHANG Zhe1,LI Xin-ling2,LIU Ming1
		Application of HTP Process in Production of Ultra-Heavy Steel With High Strength
		With the help of thermo-mechanical simulation and numerical simulation, the application of HTP process in high strength steel (yield strength is no less than 600MPa) with the thickness less than 100mm was discussed, in which Nb, Mn, Cr and B were added and two Nb content(0.09% and 0.05%) steel were contrasted. The results show that by using HTP and temper process, non-recrystallization temperature of steel plate is increased, homogeneity and toughness at center of ultra-heavy plate is obviously increased. The microstructure is mainly lath-like bainite on surface and at quarter, and grain bainite and black pearl-like at center of the thickness by different cooling rate.
		2012 Vol. 47 (2): 53-57 [Abstract] ( 2612 ) [HTML 0KB] [PDF 0KB] ( 78 )

	58	INGHU Ke-zhi1,ZHU Guo-sen1,LIU Guang-ming1,QIAO Jian-jun2,CHEN Guang2
		Simulation and Practice on Relationship Between Heat-Buckling and Initial Flatness in CALL
		The heat-buckling in CAL had bad effect on the processing, which caused economic loss to production lines. The hot buckling of thin-and-wide strips in the furnace was investigated in both mechanical theories and FEM simulation. The results show that the critical stresses for different initial flatness are quite different. After optimization and modification of the flatness target curves in TCM, the probability of hot buckling is reduced more than 50%.
		2012 Vol. 47 (2): 58-61 [Abstract] ( 1959 ) [HTML 0KB] [PDF 0KB] ( 51 )

	62	HANG Yan1,2,SHAO Fu-qun1,WANG Jun-sheng2,LIU Bao-quan2
		Research and Application of Coating Weight Adaptive Control Model for Continuous Galvanizing LineZ
		Zinc coating weight control was one of the most critical issues for continuous galvanizing line. The process had large variable-time delay, nonlinear, multivariable disturbance, so it would result in seriously coating weight error and non-uniform coating. Based on relative analysis of coating weight with air knife pressure, distance between air knives and strip speed, the model of adaptive feed-forward control, average coating and skew feedback control were presented. An accurate and uniform zinc coating weight control was realized through controlling automatically air-knife pressure, distance between air knife and strip and both sides position of air knife. From product results, the precise and stability control model can resolve effectively the above difficulties. The control model used in product application not only satisfy high quality control requirement but also realize change from manual adjustment to automation control on coating weight.
		2012 Vol. 47 (2): 62-66 [Abstract] ( 2438 ) [HTML 0KB] [PDF 0KB] ( 57 )

Materials

	67	LIU Zhi-ming,ZHANG Jiong-ming,LUO Yan-zhao
		Investigation of Surface Crack on Micro-Alloyed Steel Plate by DHCR
		In order to find out the cause of surface cracks for the same batches slab, surface crack on micro-alloyed steel plate produced by direct hot charging process was investigated by means of metallographic analysis, scanning electron microscopy, energy spectrometer analysis and transmission electron microscopy, and compared with crack-free plate produced by cool charging process. The results show that the main factors of surface crack on micro-alloyed steel plate produced by direct hot charging process are the segregation of low melting point elements such as Cu, As in slab’s cooling or heating process. Compared with hot-rolled plates produced by hot charging, the grain size of cold charged rolled plate about 10μm in diameter, while the grain size of hot-rolled plates by hot charging are large and uneven. Precipitates of hot plate are between 15 -25nm in size, the crack source are more than the matrix and a large amount of fine Nb(CN) precipitate at the boundary of the austenite grains, which decreases the strength of the grain boundary sharply.
		2012 Vol. 47 (2): 67-71 [Abstract] ( 2810 ) [HTML 0KB] [PDF 0KB] ( 53 )

	72	ZHANG Shou-lu,ZHAO Yong-xian,SONG Li-qiang
		Precipitation Behavior of Chi (χ) Phase in Super Duplex Stainless Steel 00Cr25Ni7Mo4N
		Precipitation behavior of chi (χ) phase in the super duplex stainless steel 00Cr25Ni7Mo4N was investigated during an aging process at different temperature from 600℃ to 1000℃ and during an isothermal aging process at 920℃ and 830℃. The backscatter electron detector of SEM was used to examine the amount and distribution of Chi (χ) precipitate. TEM and EDS were used to examine the structure and chemical composition of χ-phase. The results show that the precipitation temperature region of χ-phase is from 750℃ to 920℃, and the peak temperature is about 830 ℃. Comparing with σ-phase precipitation, the amount of χ-phase precipitates is few. The α/γ interfaces and the α/α grain boundaries are the main sites of χ-phase precipitates. During an isothermal aging process, it is found that the precipitation of χ-phase in the 00Cr25Ni7Mo4N steel includes four stages of initiation, rapid precipitation, saturation and transformation into σ-phase. Therefore, the χ-phase is a meta-stable phase, which will gradually transform into the σ-phase after a prolonged aging.
		2012 Vol. 47 (2): 72-75 [Abstract] ( 2678 ) [HTML 0KB] [PDF 0KB] ( 66 )

	76	WANG Zhi-gang1，ZHAO Zheng-zhi1，ZHAO Ai-min1，KUANG Shuang2
		Effects of Heat Treatment Process on Microstructure and Properties of Hot-Dip Galvanized Dual-Phase Steel
		The hot-dip galvanized 590Mpa grade cold rolling dual phase steels were trial-produced in laboratory. The effects of critical annealing temperature on microstructure and properties were investigated. Microstructure and properties were compared and analyzed between laboratory and industrial products with the same chemical compositions. The results show that the absence of bainite is usual in hot-dip progress; both the bainite content and the ultimate tensile strength increase and the elongation decrease with the increasing of critical annealing temperature. The bainite and martensite velum fraction of Industrial Products is 29%. The ultimate tensile strength and elongation is 610MPa and 31.5%, respectively, and the performance meets the requirement. The research indicate that if the volume fraction and distribution patters of the second phase (bainite+ martensite) can be controlled, the mechanical properties of hot-dip galvanized dual phase will be fully improved.
		2012 Vol. 47 (2): 76-80 [Abstract] ( 2468 ) [HTML 0KB] [PDF 0KB] ( 55 )

	81	PEI Yue-kai1,2,MA Dang-shen2,LIU Bao-shi3,CHEN Zai-zhi2,ZHOU Rong1,ZHOU Jian2
		Effect of Forging Ratio on Microstructure and Mechanical Property of H13 Steel
		Effect of different forging ratios on microstructure and mechanical properties of electrical die steel (H13) was investigated by metallographic microscope and SEM under simplex stretching and hot-forging condition. The results show that transversal impact property is much less than longitudinal in the same forging ratio. Following the forging ratio increasing, it makes merely influence on the transversal impact property, while the longitudinal impact property increases. The research shows that, the cross direction crack arrest property won’t be effectively influenced by forging ratio under simplex stretching and hot-forging condition. The forging ratio of electrical hot die steel should be controlled in four to six, which is most appropriate.
		2012 Vol. 47 (2): 81-86 [Abstract] ( 3291 ) [HTML 0KB] [PDF 0KB] ( 61 )

	87	YANG Jing-hong1,WANG Xiao-yan2,LIU Gang1
		Effect of Nb-Ti Microallyed on Welding Properties of Q345R Pressure Vessels Steel Plates
		By the mechanics test and microstructure observation, the joint weld properties of Q345R pressure vessels steel plates produced by conventional process and hot continuous rolling were investigated under different welding techniques such as shielded metal arc welding, gas metal arc welding and submerged metal arc. The hardness distribution measurements on the different welded specimens were conducted and the mechanical performance of joint weld for the steels was evaluated. The results show that the synthetics properties of continuous rolling Q345R joint weld are excellent and its impact toughness is higher than conventional process. The degree of hardening for coarsen zone of continuous rolling joint weld is least obviously. Better properties of joint weld come from microstructure refining as low carbon and Nb-Ti microalloyed design plus TMCP technology adoption.
		2012 Vol. 47 (2): 87-91 [Abstract] ( 3096 ) [HTML 0KB] [PDF 0KB] ( 53 )

	92	LU Feng1,2,KANG Jian1,WANG Chao1,WANG Zhao-dong1,WANG Guo-dong1
		Effects of Tempering Temperature on Microstructure and Mechanical Properties for Q960 High-strength Structural Steel Plates
		To develop the Q960 high-strength quenched and tempered structural steel plates, the effects of tempering temperature on the microstructure and mechanical properties of plate specimens were investigated on the same rolling and quenching conditions. The results show that with the increase of tempering temperature, the strength values of specimens are reduced, and the toughness and ductility show a mainly increasing tendency. But the temper brittleness appears at 300~450℃. The excellent overall properties of specimens with tempered sorbite can be obtained when the tempering temperature is 600℃, i.e., the yield strength is 1030MPa, tensile strength 1080MPa and percentage elongation 15.9% with the Charpy impact energy 144J at -40℃. All these indexes come up to the National Standard GB/T 16270-2009. Then the tensile behavior of specimens was discussed.
		2012 Vol. 47 (2): 92-95 [Abstract] ( 3161 ) [HTML 0KB] [PDF 0KB] ( 54 )

	96	FAN Jun1，ZHAO Jun-xue1，CHEN Yuan-ping2，ZHAI Ke-yong1，Li Hui-juan1
		Analysis on the Cause of Longitudinal Crack on the Hot-Rolled Ribbed Bar Surface
		To find the main reason of longitudinal crack on HRB335 hot-rolled ribbed bar surface in cold bending process, continuously cast product macro-acid etching test，metallographic examination，scanning electron microscope and EDAX were carried out . It is regarded that the defect is mainly caused by serious subsurface blowholes and internal cracks in the cast product, which run through the surface in the later hot working process and is oxidized. As a result, the defects can not be welded in the rolling process and the cracks happen finally. The causes of subsurface blowhole and cracks in the production process were discussed, and some suggestions to improve the production process were given.
		2012 Vol. 47 (2): 96-100 [Abstract] ( 2519 ) [HTML 0KB] [PDF 0KB] ( 98 )

Environmental Protection and Energy

	101	FAN Xin-xin1,YU Cai-yuan1，WEN Yan-ming2
		Characteristics of Gas-solid Two-Phase flow by Combining Gas with Mechanical Strength Action
		A experiment study on the characteristics of fluidizing behavior of binary particles in disturbance mixed dryer was carried out by combining gas with mechanical strength. The factors such as binary particle size, bed height and mechanical strength intension influence on characteristics of flow and heat transfer were analyzed, and the relative formula of heat transfer coefficient was obtained by dimensional analysis method. The characteristics of flow and heat transfer were improved effectively through mechanical strength action. It provides technical support for wetness-adjusting and grading integration technology of coking coal in industrialization area.
		2012 Vol. 47 (2): 101-106 [Abstract] ( 2006 ) [HTML 0KB] [PDF 0KB] ( 52 )

钢铁

　

News

　

　

·

·

·

·

·

　　　　　　　　　　More

　

Author Center

　

　

Instruction for Authors

　

　

Copyright Agreement

　

Links

　

·	Links

　　　　　　　　　　More

Copyright © IRON AND STEEL　
Supported by: Beijing Magtech