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Journal of Iron and Steel Research International 2010年第3期17卷 56-61页

作者： zhao Zheng-zhi LIU Jie zhao ai-min Metallurgical Engineering Research Institute University of Science and Technology Beijing Beijing 100083 China Shougang Research Institute of Technology Beijing 100041 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

The microstructure characteristics and precipitation behavior of automobile beam steels produced by compact strip production （CSP） were investigated by use of scanning electron microscopy （SEM） transmission electron microscopy （TEM） and X-ray energy dispersive spectroscopy. The result shows that the final microstructure is mainly composed of polygonal ferrite and small amount of pearlite, and the average ferrite grain size is about 3-6μm. Small amount addition Ti to aluminium-killed steel can help to refine the microstructure and improve the mechanical properties. A large number of fine precipitates have been observed in automobile beam steels. The mean particle size is about 10-30 nm. Remarkable strengthening and grain refinement can be obtained by these nano-particles.

关键词： compact strip production microstructure precipitation behavior

Precipitation of AlN and MnS in Low Carbon Aluminium-Killed Steel

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Journal of Iron and Steel Research International 2012年第4期19卷 51-56页

作者： CHEN Yin-li WANG Yan zhao ai-min (Engineering Research Institute University of Science and Technology Beijing Beijing 100083 China)

The precipitation kinetics of AlN and MnS in low carbon aluminium-killed steel was *** electron microscopy（TEM）,energy disperse spectroscopy（EDS） and phase analyses have been used to investigate the morphology,compositions and particle size distribution of AlN and MnS precipitates in three positions of the *** particles of AlN and MnS precipitates in the ferrite region after coiling and distributes along and adjacent to the ferrite grain *** shapes of AlN are plate-like,the precipitates size is about 10 to 60 nm;the shapes of MnS are spherical,the precipitates size is about 200 to 600 *** precipitation behavior of AlN is sensitive to the isothermal temperature and holding time,the precipitation quantity and particle size distribution of AlN in different positions of coil are unequal

关键词： precipitation kinetics morphology low carbon steel aiN MnS

Semisolid Slurry Preparation of Die Steel with High Chromium Content

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Journal of Iron and Steel Research International 2004年第5期11卷 8-12页

作者： MAO Wei-min zhao ai-min ZHANG Li-juan ZHONG Xue-you University of Science and Technology Beijing

The control model of laminar cooling system for hot strip, including air-cooling model, water-cooling model, temperature distribution model along thickness direction, feedforward control model, feedback control model and self-learning model, was introduced. PID arithmetic and Smith predictor controller were applied to feedback control. The sample of model parameter classification was given. The calculation process was shown by flow chart. The model has been proved to be simple, effective and of high precision.

关键词： hot strip laminar cooling control model Smith predictor

Preparation of Semisolid Slurry for Stainless Steel 1Cr18Ni9Ti

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Journal of Iron and Steel Research International 2004年第3期11卷 11-14页

作者： MAO Wei-min zhao ai-min YUN Dong ZHANG Le-ping ZHONG Xue-you University of Science and Technology Beijing

The controlled runout table cooling is essential in determining the final mechanical properties and flatness of steel strip. The heat of a hot steel strip is mainly extracted by cooling water during runout. In order to study the heat transfer by water jet impingement boiling during runout,a pilot facility was constructed at the University of British Columbia. On this pilot facility,the water jet impingement tests were carried out under various cooling conditions to investigate the effect of processing parameters,such as cooling water temperature,water jet impingement velocity,initial strip temperature,water flow rate,water nozzle diameter and array of water nozzles,on the heat transfer of heated strip. The results obtained contribute to the optimization of cooling water during runout.

关键词： cooling water controlled runout table hot strip mill

Centrifugal Casting of High Speed Steel/Nodular Cast Iron Compound Roll Collar

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Journal of Iron and Steel Research International 2002年第1期9卷 32-35页

作者： FU Han-guang zhao ai-min XING Jian-dong FU Ding-mei Xi'an Jiaotong University University of Science and Technology Beijing

The centrifugal casting of compound HSS/nodular cast iron roll collar was studied,and the factors affecting transition zone quality were *** pouring temperature and interval in pouring are the main factors affecting transition zone *** controlling process parameter and flux adding during casting,high quality roll collar was *** cause,why in the casting of HSS part,segregation appears easily,was analyzed and the countermeasure eliminating segregation was put forward,the measure eliminating heat treatment crackling was also put forward.

关键词： high-speed steel nodular cast iron centrifugal compound casting combining layer roll collar

Precipitation Behavior and Textural Evolution of Cold-Rolled High Strength Deep Drawing Dual-Phase Steels

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Journal of Iron and Steel Research International 2013年第12期20卷 61-68页

作者： WANG Zhi-gang zhao ai-min zhao Zheng-zhi YE Jie-yun CHEN Jing-jing HE Jian-guo School of Materials and Science Engineering Jiangxi University of Science and Technology National Engineering Research Center of Advanced Rolling University of Science and Technology Beijing

Low-carbon Cr-Mo micro-alloyed deep drawing dual-phase steels were designed in laboratory. As the mi- crostructure 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, aiN and MnS, and with the increase of Mo addition, finer and denser MoC par- ticles 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 ~lll~//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.

关键词： dual-phase steel precipitation~ Mo r value texture

Effects of Rolling Parameters on Texture and Formability of High Strength Ultra-Low Carbon BH Steel

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Journal of Iron and Steel Research International 2013年第6期20卷 75-81页

作者： CHEN Yin-li SU Lan zhao ai-min KUai Zhen LI Ben-hai LIU Guang-ming Engineering Research Institute University of Science and Technology Beijing Shougang Research Institute of Technology

The effects of hot rolling and cold rolling parameters on texture and r （ plastic strain ratio ） value of high strength ultra low carbon bake hardening （ ULC-BH ） steels are studied with orientation distribution function （ ODF ） structural analysis *** hot rolling , the high strength ULC-BH steel sheet has weakγ-fiber with uniform orientation distributions , and weakα-fiber , of which { 445 } component forms a high intensity peak at coiling temperature of 750℃.After cold rolling , both { 111 } -{ 111 } intensity on theγ-fiber and{ 111 -}{ 112 } intensity on theα-fiber *** a result of substitutional solute elements Mn and P being added to the steel , strong { 112 } deformation texture component is observed onα-fiber , especially at 80%cold rolling reduction , and this leads to the strong { 111 } recrystallization texture after *** increase of cold rolling reduction shifts the maximum intensity on theγ-fiber from { 111 } to { 111 } .After annea-ling , a very strongγ-fiber is obtained , with intensity peak at { 111 } component when cold rolling reduction reaches 80%.Increasing coiling temperature and cold rolling reduction improveγ-fiber intensity and r value , resulting in good deep drawability.

关键词： hot rolling cold rolling texture bake hardening steel

Formability of Fe-Mn-C Twinning Induced Plasticity Steel

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Journal of Iron and Steel Research International 2013年第11期20卷 111-117页

作者： HUANG Yao zhao ai-min MI Zhen-li JING Hai-tao LI Wen-yuan HUI Ya-jun Engineering Research Institute University of Science and Technology Beijing ME Department SaiC Motor Passenger Vehicle Co. Shougang Research Institute of Technology

A comparative analysis of formability was investigated between F^Mn-C twinning induced plasticity steel with different Mn contents and interstitial free steel. Tensile test combing with the morphology of fracture reveals that element Mn is helpful for the forming of inclusion or particles with film or rod shapes inducing the crack initia- tion and propagation. During stamping process, twinning induced plasticity steel without earing shows better anisot- ropy than interstitial-free steel because a typical 〈111〉 fiber texture forms accompanied by a weaker 〈100〉 fiber texture. The difference between the two steels is not evident during Erichsen cone cupping test, but the result of cone cupping test indicates that the twinning induced plasticity steel has superior drawing ability compared with intersti tial-free steel. The different performances can be attributed to the different deformation mechanism during cupping test. FED （forming limit diagram） of tested steels further suggests twinning induced plasticity steel has slightly su- perior deep drawability but low stretchability than that of IF steel, whose FLD0 value can reach 30%.

关键词： TWIP steel earing cone cupping forming limit diagram

Corrosion properties of high silicon iron-based alloys in nitric acid

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China Foundry 2007年第4期4卷 276-279页

作者： LI Ju-cang WANG Shu-ying zhao ai-min WANG Li-na LIU Feng-he University of Science and Technology Beijing Beijing 100083 China Jiuquan Iron and Steel （Group） Corporation Limited Jiayuguan 735100Gansu.China

The effect of copper and rare-earth elements on corrosion behavior of high silicon iron-based alloys in nitric acid was studied by means of static and loading current corrosion *** anodic polarization curve was also made to discuss the corrosion *** examination on alloy microstructure and SEM corrosion pattern showed that when silicon content reached 14.5%,the Fe3Si phase appeared and the primary structure of the iron-base alloy was *** adding 4.57% copper in the iron alloy,its corrosion resistance in static diluted sulfuric acid was improved while its corrosion resistance and electrochemical corrosion properties in the nitric acid were *** contrast,the addition of rare earth elements could improve the corrosion properties in all above conditions including in static diluted sulfuric acid and in nitric acid.

关键词： polarization curve corrosion resistance microstructure corrosion pattern iron-based alloys

Role of cyclooxygenase-2 signaling pathway dysfunction in unexplained recurrent spontaneous abortion

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Chinese Medical Journal 2010年第12期123卷 1543-1547页

作者： WANG Yu zhao ai-min LIN Qi-de Department of Obstetrics & Gynecology Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai 200127 China

Background Experimental evidence indicates that cyclooxygenase-2 （COX-2） plays a critical role in blastocyst implantation; however, little is known of the role of COX-2 in unexplained recurrent spontaneous abortion （URSA）. Methods We evaluated the expression level and potential signaling pathway of COX-2 in 30 cases of URSA who were excluded the abnormality of chromosomes, anatomy, endocrine, infectious, autoimmune diseases and in 30 normal pregnancies. Results The mRNA and the protein expression level of COX-2 in the URSA group （-0.238±0.848, 0.368±0.089, respectively） were significantly lower than that in the control group （1.943±3.845, 1.046±0.108, respectively）（both, P 〈0.01）. The expression of prostaglandins PGF2a, PGD2, PGE2, and PGI2, in the URSA group （（2326.0±295.6） pg/ml, （2164.0±240.5） pg/ml, （238.7±26.4） pg/ml, （2337.0±263.0） pg/ml, respectively） were significantly lower than that in the control group （（3450.0±421.7） pg/ml, （3174.0±415.6） pg/ml, （323.5±43.8） pg/ml, （3623.0±460.4） pg/ml, respectively）（P 〈0.05）. The mRNA expression level of PPARI3 and RXRa （0.859±0.653, -0.172±0.752, respectively） in URSA group was significantly lower than that in the control group （1.554±1.735, 0.777±2.482, respectively）（both P 〈0.05）. The mRNA and protein expression levels of vascular endothelial growth factor-A （VEGF-A） in the URSA group （2.010±1.522, 0.35±0.46） was significantly lower than that in the control group （4.569±2.430, 0.750±0.350）（both P 〈0.05）. Conclusions COX-2 and the COX-2-derived PGI2 signaling pathway possibly play an important role in successful embryo implantation, and their decreased expression may result in URSA. The decreased expression may influence the expression of VEGF-A which interferes with placental angiogenesis causing failure of embryo implantation, leading to spontaneous abortion.

关键词： unexplained recurrent spontaneous abortion cyclooxygenase-2 prostaglandin 12 proliferator-activated receptor β/retinoid X receptor a vascular endothelial growth factor-A blastocyst implantation