钢铁
Home
|
About Journal
|
Editorial Board
|
Instruction for Authors
|
Subscriptions
|
Advertisement
|
Contacts Us
|
Chinese
Office Online
Author Center
Peer Review
Editor Work
Office Work
Editor-in-chief
Journal Online
Forthcoming Articles
Current Issue
Archive
Read Articles
Download Articles
Email Alert
Quick Search
Advanced Search
2013 Vol. 48 No. 7
Published: 2013-07-15
Technical Reviews
Steelmaking
Metal Forming
Materials
Environmental Protection and Energy
Technical Reviews
1
WANG Yi-de,TANG Di,MI Zhen-li,WU Hua-jie
The Development Status and Consideration of Special Steel Industry in China
A brief view of the special steel industry in China was introdued, including its history of development, the gap of the overall development level and the steel quality of typical grades between China and international advanced level and its reason, the advance and promotion of our equipment and technology, and so on. Several noteworthy problems that show up during the period of the development of our special steel industry were discussed, such as the merger and reorganization of enterprises, the rational utilization of special steel resources and the technological change of the production process from short process to long process. The problems existed in our special steel industry were discussed and some relative suggestions were put forward in the end.
2013 Vol. 48 (7): 1-6 [
Abstract
] (
1561
) [
HTML
0KB] [
PDF
0KB] (
102
)
Raw Materials and Ironmaking
7
HAN Yue-xin,REN Duo-zhen,SUN Yong-sheng,GAO Peng
Phosphorus Migration Behaviors in Reduction of High Phosphorus Oolitic Hematite Ore
For the high phosphorus oolitic hematite ore, coal-based reduction technology was investigated. Single-factor experiments were carried out to investigate the effect of reduction temperature, reduction time, C/O mole ratio and CaO addition on the phosphorus migration behaviors in the reduction of high phosphorus oolitic hematite. After the phosphorus into the iron powder was analyzed, the results show in a certain aspects below. First, both the grade and recovery of phosphorus into the iron powder increase respectively following the rise of reduction temperature as well as the extension of time. Second, with the enlargement of C/O mole ratio, the grade of phosphorus shows a rising before dropping down. Third, the grade of phosphorus is not been influenced much on CaO addition. In addition, XRD and SEM analysis of reduced materials further reveal that elemental phosphorus can be gained after reduction and most of them migrated into the iron powder. A preliminary exploration ophosphorus migration behavior in reduction of high phosphorus oolitic hematite is conducted and a theoretical basis for further study on the high phosphorus oolitic hematite is provided as well.
2013 Vol. 48 (7): 7-11 [
Abstract
] (
1321
) [
HTML
0KB] [
PDF
0KB] (
111
)
12
LIU Ran,WANG Xing-juan,LIANG Chun-zhao,L Qing,FENG Shuai，DU Lin-sen
Combustion Rate of Pulverized Coal Through Preheating Pulverized Coal
Two kinds of pulverized coal injected from Handan steel was preheated with muffle furnace. Their weight loss rate and combustion rate was measured at different preheating temperature, and the surface structure of pulverized coal was observed by scanning electron microscopy (SEM). Experimental results show that weight loss rate of bituminous coal preheated 150℃ is 5.12%, with increase in preheated temperature, weight loss rate of pulverized coal is increasing. Bituminous coal weight loss rate is 17.24% under preheating 300℃. Preheated anthracite coal weight loss rate changes little; anthracite coal only reaches 5.66% at 300℃. After preheating the pulverized coal combustion rate obviously improves, bitumite coal combustion rate can reach 89.74%, improved 15.67% than bituminous row coal, anthracite coal combustion rate is 85.19%, improved 24.80% than anthracite row coal. After preheating, the pulverized coal surface structure has obviously changing, layered and pore structure is increased, which can improve the combustion rate of pulverized coal and provide theoretical basis for improving combustion rate by preheating pulverized coal.
2013 Vol. 48 (7): 12-16 [
Abstract
] (
1345
) [
HTML
0KB] [
PDF
0KB] (
111
)
17
QING Ge-le,,WU Keng,QU Jun-jie,LIU Wen-wang,TIAN Yun-qing,WANG Meng
Effect of Different Magnesium Additives on Process Parameters and Pellet Quality
MgO has negative effect on the quality of sinter with high iron and low silica. However, MgO can improve metallurgical properties of pellet. Therefore, adding of MgO into pellet instead of into sinter can optimize the quality both of sinter and of pellet. Different magnesium additives have different influence on pellet process parameters and quality due to their varied physicochemical characteristic. The effect of different magnesium additives such as dolomite, serpentine, boron mud and magnesia on pelletizing, firing, physicochemical and metallurgical properties of pellet under high iron and low silica condition were investigated experimentally. The most effective additive for improving the quality of pellet is gained by comparison analysis, which lays foundation for industrial production of magnesium pellet.
2013 Vol. 48 (7): 17-22 [
Abstract
] (
1352
) [
HTML
0KB] [
PDF
0KB] (
103
)
23
JI Yong-hua,QIN Bing-ke,WANG Chun-xia,SHI Kai-yi
Process Concept to Produce Formed Coke by Using Meager-Lean Coal
The process concept of making formed coke was discussed through using meager-lean coal. The effect of technological conditions (such as size distribution of blended coal, the proportion of blended meager-lean coal, the rate and time of carbonization and final carbonization temperature) on the quality of formed coke was investigated with the orthogonal experiment. The results show that the optimum conditions were: the size composition of blended coal is less than 1mm, the proportion of meager-lean coal is 70%, the rate and time of carbonization respectively is 4℃/min and 4h, the final temperature of carbonization is 900℃. The formed coke, which is made under mentioned above conditions, is comply with the requirements of the national level of the second class metallurgical coke.
2013 Vol. 48 (7): 23-26 [
Abstract
] (
1436
) [
HTML
0KB] [
PDF
0KB] (
116
)
Steelmaking
27
CHANG Jin-bao,MA De-gang,LI Shuang-wu,HAN Zhi-jie,LIU Shan-xi,XUAN Zong-yu
Clogging Mechanism of Nozzles for Billet Continuous Casting of Welding Wire Steel Containing Titanium
The properties of inclusions in the welding wire steel and phases of caster nozzles were investigated by SEM, and the forming mechanism of the nozzle clogging was also studied by thermodynamic calculation. The results shows that large amounts of Al2O3 and TiO2 inclusions exist in the molten steel at the end of LF refining, and precipitates on the inner nozzles to form the clogging of alumina type, titania type, and two both individually, the continuous heats are merely 4. By optimizing the relationship of ［Al］-［Ti］-［O］ to make the content of w(［Al］) above the equilibrium line between Al-Ti, w(［Ti］)/w(［Al］)4/3>84.49, and w(［Ti］)/w(［Al］)>7.46, when w(［Al］) less than 0.0068%, the Al2O3 inclusions decrease obviously, the nozzle clogging can be efficiently reduced, and the continuous casting heats increase to 6.
2013 Vol. 48 (7): 27-31 [
Abstract
] (
1588
) [
HTML
0KB] [
PDF
0KB] (
83
)
32
ZHAO Xin-yu,LIU Yang,ZHEN Xin-gang,WANG Hai-bao,WANG Wen-jun,ZOU Yang
Variation of Hot Ductility and Microstructure Morphology of Slab Surface During Period of Intensive Cooling and Reheating Under Controlled Cooling
The samples of diameter 10 mm were made to simulate slab surface. The variation of hot ductility and microstructure morphology of slab surface during the period of intensive cooling and reheating treatment under surface structure controlled cooling was studied with the Gleeble-2000D hot simulation tester. The theoretical basis will be provided to apply on vertical bending caster of surface structure control cooling. The results show that: the hot ductility of the samples is deteriorated because of the form of widmanstatten structure and film-like proeutectoid ferrite along grain boundary during the period of intensive cooling. However, the treatment of reheating can effectively eliminate the deterioration of hot ductility producing during the period of intensive cooling, which makes the reduced area of the samples increasing to over 40%. Therefore, the treatment of intensive cooling should be accomplished before the slab enters the segment of bending. The slab can enter the bending segments during the period of reheating when the controlled cooling is applied on vertical bending caster.
2013 Vol. 48 (7): 32-35 [
Abstract
] (
1219
) [
HTML
0KB] [
PDF
0KB] (
110
)
36
CHEN You-gen,,Wolfgang Mossner,GAO Hai-chao,LONG Sheng-ping
Technological Innovation and Practice of Liquid Core Reduction for CSP Caster
The technological innovation and practice of liquid core reduction (LCR) of CSP caster was introduced, the effect of the amount of liquid core reduction on the slab shape, the slab internal quality and the rolling process was analyzed. Results show that the maximum amount of liquid core reduction from the original design of the 20mm increased to 35mm is feasible in Masteel existing equipment conditions, the reduction rate can reach 38.8%. The technology is successfully developed, not only increase production flexibility, but also get good metallurgical effects.
2013 Vol. 48 (7): 36-39 [
Abstract
] (
1613
) [
HTML
0KB] [
PDF
0KB] (
103
)
Metal Forming
40
LI Rong-min,,YANG Li-po,YU Bing-qiang,LIU Hong-min,DU Chang-zheng
Effect of Detection Roll Installation Precision on Online Shape Signal of Cold Rolling Strip
Based on the geometry and shape detection theory, the shape signal compensation model for installation error of the detection roll was established. Combined with two installation methods of the fixed wrap angle and the variable wrap angle, comprehensive compensation of the cold rolling strip shape signal was done based on the horizontal error and the vertical error. For the fixed wrap angle, the shape compensation amount could be set to a constant. For the variable wrap angle, dynamic compensation amount must be calculated based on the dynamically wrapping angle formula. Based on the theoretical analysis and practical industrial datum, suitable allow installation error could be developed by mill characteristics to maximize shape detection accuracy, and comprehensive compensation shape curve could more realistically reflect the actual shape status of online cold rolling strip.For example of a 1050 mill, the horizontal tilt amount was recommended less than 0.03mm, the vertical tilt amount was controlled in less than 0.05mm, the basic shape control technology requirements could be satisfied.
2013 Vol. 48 (7): 40-48 [
Abstract
] (
1592
) [
HTML
0KB] [
PDF
0KB] (
103
)
44
CUI Gui-mei,ZHAO Ji-wei,LI Zhong-de
Control of Torsional Vibration Based on Real Time Detection of Torque by Wireless Transducer
The vibration in rolling process is inevitable problem, especially in the sudden strong impact and unloading. The vibration phenomenon is very serious. Through adopting the wireless sensor of torque to get the disturbance of vibration, it was solved the problem that the existing torsional vibration suppression method using the torsional vibration controller to calculate vibration always get the deviation. Based on the two closed loop in the AC electric drive system—torture current and speed loop, using the principle that the feed-forward of disturbance compensation can control the disturbance, the torque disturbance compensation in the torque controller was added to control the vibration before it happen. The Simulink was used to get the result of controlling vibration. The result shows that the measure of the torsional vibration feed-forward control based on real-time detection of the torque could effectively control the torsionai vibration. And the most important thing is these measures are close to the reality.
2013 Vol. 48 (7): 44-48 [
Abstract
] (
1279
) [
HTML
0KB] [
PDF
0KB] (
89
)
49
CHEN Dan,HE Xu-ling,GAO Lei,GUO Li-wei,LI Shu-chang
On-Line Calculation of Five-Stand Tandem Cold Rolling Mill Using a New Method of Load Distribution
A new method of load distribution was introduced. There was deviation of calculated exit thickness of the last stand and product thickness with the traditional experience table using relative reduction. Therefore, the logarithmic compensation method was used to correct deviation and improve its accuracy; In order to ensure the calculation process maintain steady as having artificial modification, the exponential smoothing method was used to correct deformation; To realize dynamic adjustment and satisfy on-line control, the rolling force limit and rolling- power balance correcting of reduction was considered. The calculated deformation of the fourth stand was assigned to the second, third, fourth stand through regression calculation to ensure the minimization of the fluctuation of mill exit thickness and realization stable rolling. This new method of load distribution can meet the requirement of real-time control and ensure product thickness accuracy.
2013 Vol. 48 (7): 49-52 [
Abstract
] (
1467
) [
HTML
0KB] [
PDF
0KB] (
126
)
Materials
53
YANG Yan-hui,,WANG Mao-qiu,CHEN Jing-chao,DONG Han
Fatigue Properties of Gear Steels After High Temperature Carburizing
The fatigue properties of microalloying gear steels with Nb and Ti (steel A1:w(Nb)0.077%; steel A2:w(Nb)0048%+w(Ti)0.038%) after carburized at 1000℃ were investigated by means of rotating bending fatigue tests. The results show that the precipitates in steel A2 microalloyed with Nb and Ti are smaller in size and higher in volume fraction than those in steel A1 microalloyed only with Nb resulting in the higher fatigue limit for steel A2 compared with steel A1. The SEM observation of fracture surface show that the fatigue crack initiates from the near surface matrix for both steels, and it propagates around grain boundaries in the carburized case, and thus superior fatigue properties are found for steel A2 with finer and more uniform prior austenite grains in carburized case layers.
2013 Vol. 48 (7): 53-57 [
Abstract
] (
1605
) [
HTML
0KB] [
PDF
0KB] (
116
)
58
FANG Xu-dong,,HAN Pei-de
Development of TP310HCbN Seamless Pipe of TISCO for Ultra-Supercritical Power Plant Boiler
According to the characteristics of the environment for the use of ultra-supercritical thermal power units key stainless steel, the principle of the TISCO heat-resistant steel TP310HCbN design, strengthening mechanisms, technical measures and the production process was set forth. The microstructure, weld and precipitates were researched by using TEM and EDS analysis test, and the conventional mechanical properties, high-temperature tensile properties and creep and rupture mechanical were investigated. The development of TP310HCbN heat-resistant seamless steel pipe has uniform organization and comprehensive performance, and the products has entered the stage of mass production.
2013 Vol. 48 (7): 58-64 [
Abstract
] (
1381
) [
HTML
0KB] [
PDF
0KB] (
116
)
65
ZHAO Lian-yu,ZHANG Zhi-jun,SHI Xian-bo,,YAN Wei,SHAN Yi-yin,YANG Ke
Microstructure and Mechanical Property of X70 Grade High Deformability Pipeline Steel
The (PF+B) dual-phase microstructure steel and AF microstructure steel were obtained based on alloy design, phase-transformation study and industrial trail rolling. Studies on microstructure and mechanical property of the (PF+B) steel and AF steel show that the polygonal ferrite (PF) phase appears when the relaxation is made below the Ar3 point, bainite (B) microstructure which is mainly composed of granular ferrite and bainite ferrite is obtained with accelerated cooling at 20℃/s after the termination of relaxation at proper temperature. The mechanical property of (PF+B) dual-phase microstructure shows obvious differences with the traditional AF microstructure. The steel with (F+B) microstructure has lower yield/tensile ratio and higher elongation than the AF microstructure steel, indicating a better deformability. An X70 grade pipeline steel with (F+B) microstructure was obtained, with wall-thickness of 30.8mm, which can meet the requirement for the offshore pipeline steel.
2013 Vol. 48 (7): 65-69 [
Abstract
] (
1448
) [
HTML
0KB] [
PDF
0KB] (
120
)
70
ZHANG Hai-quan,XIE You,CHENG Guo-guang,CHEN Lie,KOU Yu-shan
Characteristics of Inclusions in High Sulfur Gear Steel SAE8620H Hot-Rolled Round Bar
The size, quantity, distribution, morphology and composition of inclusions in cross section and longitudinal section of high sulfur gear steel SAE8620H hot-rolled round bar produced with the EAF-LF-CC process were synthetically investigated by means of optical microscopy, scanning electronic microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that the inclusions are mainly MnS and oxide-sulfide duplex inclusions formed by MnS or (Ca,Mn)S precipitating upon Al2O3 and MgO-Al2O3; the number of inclusions increases and the ratio of oxide-sulfide duplex inclusions decreases from surface to center of high sulfur gear steel SAE8620H hot-rolled round bar; the diameter and the aspect ratio of inclusions in cross section are mainly less than 2μm and 3 respectively;In the longitudinal section, the average length of inclusions is 11μm, the average length of inclusions at surface is less than that of center by 3μm and the ratio of spindle inclusions is only 30%.
2013 Vol. 48 (7): 70-75 [
Abstract
] (
1739
) [
HTML
0KB] [
PDF
0KB] (
117
)
76
BAI Xiao-hong,LIU Dong-sheng
Development of Low C Hot-Rolled Formable Strip Steel With Yield Strength of 700MPa
A low carbon SiMnTiNb ultra-high strength hot-rolled strip steel with yield strength of 700MPa was developed by thermo-mechanically controlled processing (TMCP) on a conventional 1450mm hot strip production line. Continuous cooling transformation (CCT) diagram of the industrially produced steel was constructed. Precipitation-hardening behavior was analyzed by the hardening response of a series of aging experiment. Mechanical properties, cold bending property, and weldablity of the industrially rolled strip were tested. The microstructure of the strip consists of fine ferrite grains sized at 4-5μm containing precipitates of Nb-Ti, bainite and martensite. The ultra-high strength is attributed to grain refinement, precipitation and phase transformation hardenings，etc. Cold bendability and welding properties are satisfactory.
2013 Vol. 48 (7): 76-83 [
Abstract
] (
1484
) [
HTML
0KB] [
PDF
0KB] (
78
)
Environmental Protection and Energy
84
PENG Qing-liang,TANG Ping,WEN Guang-hua,LIU Bing-yu,LI Ju-zhong
Slag Composition Control for the Re-Utilization of LF Hot Steel Slag
In order to realize the re-utilization of LF hot steel slag, the change of LF refining slag composition, desulphurizing capacity and ability for absorption of inclusion was investigated in the currently process of hot re-utilization in WISCO. The results show that, after re-utilization of LF hot steel slag, desulfurization efficiency can reach more than 90%, sulphur content of molten steel can reach 0.001% in the end of refining, the total oxygen in molten steel can reduce 17.50×10-6, nitrogen content can reduce 17.00×10-6, inclusion’s content can reduce 4.47 per square millimeter relative to not cycle. According to the refining effect after two cycle, through controlling the slag amount of recycling and lime amount of replenishing , the following results can be obtained, such as the sulphur content in the initial slag less than 0.20%, the basicity of final slag in the range of 12.00-20.00, w(CaO)/w(Al2O3) in the range of 1.75-2.00. The desulfurization efficiency and w((S))/w(［S］) are not limited by cycle times.
2013 Vol. 48 (7): 84-88 [
Abstract
] (
1610
) [
HTML
0KB] [
PDF
0KB] (
62
)
钢铁
News
·
·
·
·
·
More
Author Center
Instruction for Authors
Template
Copyright Agreement
Links
·
Links
More
Copyright © IRON AND STEEL
Supported by: Beijing Magtech
