材料期刊网

AN EXPERT SYSTEM FOR COMPUTER AIDED ALLOY STEEL DESIGN—ASPRES

CHEN Yu , CHEN Nianyi Shanghai institute of Metallurgy , Academia Sinica , Shanghai , China PENG Ping , KONG Bingyu Iron and Steel Research Institute , Shanghai Baoshan Iron and Steel Complex , Shanghai , China professor , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

An alloy steel pattern recognition expert system,ASPRES,has been established for the purpose of computer aided optimal design of alloy steel in compositions and process pa- rameters,Pattern recognition techniques are used to abstract inner relationship between mechanical properties and process variables.The ASPRES uses 2-dimensional graph as visual knowledge to represent domain expertise of specific object.Forward and back- ward chaining can be utilized by researcher in predicting sample performances or giving helpful suggestions about the chemical compositions and process parameters according to desired properties.

关键词: pattern recognition , null , null

EFFECT OF SILICON ON PRODUCING DUCTILE IRON WITH COMPLEX STRUCTURE OF BAINITE AND MARTENSITE

Y. P. Zhang , J.X. Zhu , Y. Q. Wang and J.Y.Su(Institute of Cast Iron Research , Xi'an University of Technology , Xi'an 710048 , China)(Department of Mechanical Engineering , Xi'an Jiaotong University , Xi'an 710049 , China)

金属学报(英文版)

This paper deals with an important role of silicon in producing ductile iron with quenched complex structure of bainite and martensite. The samples are cast in permanent mold and quenched in solution of sodium silicate. The result of thc experiments shows that the austenizing temperature should rise with increasing silicon content, otherwise much undissolved ferrite is present in the matrix after quenching. However the undissolvec ferrite can be decreased greatly or even eliminated by adding appropriate amount of ooron. On this condition, the amount of bainite gets increasing and the amount of residual austenite decreasing with the silicon cortent increasing. An approach has also been made to the mechanism of the effect of silicon on the transformation of bainite in ductile iron. The T.T.T. curves measured show that the increase of sllicon content causes the curve to shift to the left. This is quite different from the fact in steel.

关键词: ductile iron , null , null , null

Roasting Properties of Pellets With Iron Concentrate of Complex Mineral Composition

FAN Jian-jun , QIU Guan-zhou , JIANG Tao , GUO Yu-feng , CAI Mei-xia

钢铁研究学报(英文版)

Investigation was conducted on roasting properties of pellets with an iron concentrate of complex mineral composition. The results indicated that the pellets of complex mineral composition concentrate required higher preheating temperature and longer preheating time than that of single magnetite concentrate. Therefore, it is difficult for preheated pellets to withstand the mechanical collision in the roasting process in rotary kiln. It was found that after the iron concentrate being subjected to high pressure roll grinding, the specific surface area reached 2029.1 cm2/g. Consequently, the preheating and roasting temperature of pellets were decreased by 70 and 50 ℃ and preheating and roasting time were decreased by 2 and 4 min, respectively. Meanwhile, the compression strength of preheated and roasted pellets were increased by 200 N for a pellet and 220 N for a pellet, respectively. The mechanism lied in that the increase of specific surface area activated thermal reaction and promoted formation of iter-grain bridge.

关键词: pellet , iron concentrate , high pressure roll grinding (HPRG) , specific surface area

Investigation on Initial Stage of Electroless Deposition on Low Carbon Steel and Pure Iron

Yiyong WU , Yongqian WANG , Yongzhong ZHANG and Mei YAO (School of Materials Science and Technology , Harbin Institute of Technology , Harbin , 150001 , China)Xinguo HU(Applied Chemical Department , Harbin Institute of Technology , Harbin , 150001 , China)

材料科学技术（英）

Initial process is influenced by substrate microstructure according to the study of initial stage of electroless plating on low carbon steel and pure iron. For low carbon steels, depositing on cementite is prior to that on ferrite, and for pure iron, the grain boundaries and some favourable grains are deposited more easily. The initial reactions of electroless depositing of Ni-P alloy have been tentatively proposed

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Mechanism of Bainite Nucleation in Steel, Iron and Copper Alloys

Mokuang KANG , Ming ZHU , Mingxing ZHANG

材料科学技术（英）

During the incubation period of isothermal treatment (or aging) within the bainitic transformation temperature range in a salt bath (or quenching in water) immediately after solution treatment, not only are the defects formed at high temperatures maintained, but new defects can also be generated in alloys, iron alloys and steels. Due to the segregation of the solute atoms near defects through diffusion, this leads to non-uniform distributions of solute atoms in the parent phase with distinct regions of both solute enrichment and solute depletion. It is proposed that when the Ms temperature at the solute depleted regions is equal to or higher than the isothermal (or aged) temperature, nucleation of bainite occurs within these solute depleted regions in the manner of martensitic shear. Therefore it is considered that, at least in steel, iron and copper alloy systems, bainite is formed through a shear mechanism within solute depleted regions, which is controlled and formed by the solute atoms diffusion in the parent phase.

关键词: Pre-bainite phenomenon , null , null , null

VARIATION OF HYDROGEN CONTENT IN MOLTEN HEAVY RAIL STEEL AT PANZHIHUA IRON AND STEEL COMPANY

XIAN Aiping LI Peiji CHEN Wenxiu WANG Yikang Institute of Metal Research , Academia Sinica , Shenyang , ChinaCHEN Renyi MEI Dongsheng Panzhihua Institute of Iron and Steel Research , Panzhihua , China associate professor.Institute of Metal Research , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

At panzhihua Iron and Steel Company,hydrogen content in molten heavy rail steel is rather low during smelting in the oxygen top-blown converter,and sloightly increases in tapping and pouring.Average H content varies from 2.0(dry season)to 2.4 ppm(rainy season)at smelt- ing end;2.8 ppm in ladle;and 2.1 ppm(dry season)to 2.3 ppm(rainy season)in mould, which is on a level with RH vacuum circle.The low hydrogen content in molten steel,which is due to both the very dry climate in Panzhiihua region and the LD smelting process,is the main reason why there is little flake in the heavy rail produced by Panzhihua Iron and Steel Com- pany.

关键词: smelting , null , null , null , null

Treatment of Reused Comprehensive Wastewater in Iron and Steel Industry With Electrosorption Technology

ZHANG Yunhua , GAN Fuxing , LI Meng , WANG Dihua , HUANG Zhongmai , GAO Yunpeng

钢铁研究学报(英文版)

Electrosorption technology was used to treat the reused comprehensive wastewater from iron and steel industry. A problem of relatively high conductivity of wastewater which greatly affects the reuse was examined, and industrial test was conducted for the reused water advanced deionization and purification in a comprehensive wastewater treatment plant of WISCO [Wuhan Iron and Steel (Group) Corporation]. The results of the onsite industrial test showed a satisfactory treatment performance for the reused water even at a flow rate of 1000 L/h in a standard 500 L/h unit. The average conductivity decreased by about 70%, from 580-780 μS/cm to 100-350 μS/cm. The average removal efficiency of Cl- and Ca2+ was about 75% and 68%, respectively, and CODCr of the treated water was also reduced in some degree while the pH value was almost unchanged. The energy consumption was as low as 06 kWh/t, which was remarkably superior to the conventional technologies. Therefore, it is entirely feasible that the novel electrosorption technology can be used in enhanced desalination and purification treatment of reused comprehensive wastewater in iron and steel industry.

关键词: electrosorption , desalination , purification , conductivity , industrial reused water

Abrasive Wear Behavior of High Chromium Cast Iron and Hadfield Steel—A Comparison

Mehdi Mazar Atabaki , Sajjad Jafari , Hassan Abdollah-pour

钢铁研究学报(英文版)

Abstract： Wear properties of two different crushers used for grinding raw materials of cement industry are compared using pin-on-disk wear test. The wear test was carried out with different loads on a pin. Abrasive wear behavior of two alloys was evaluated by comparing mass loss, wear resistance, microhardness and friction coefficient. The microstructure of the specimens was detected using optical microscope. The results showed that abrasive wear of high chromium cast iron is lower than that of Hadfield steel. Due to the presence of M7C3 carbides on the high chromium cast iron matrix, impact crushers exhibited higher friction coefficient.

关键词: Key words: abrasive wear , Hadfield steel , high chromium , cast iron

EFFECT OF REMOVING HYDROGEN FROM HEAVY RAIL STEEL BLOOMS BY STACK COOLING IN PANZHIHUA IRON AND STEEL COMPANY

XIAN Aiping LI Peiji CHEN Wenxiu WANG Yikang Institute of Metal Research , Academia Sinica , Shenyang , ChinaCHEN Renvi MEI Dongsheng Panzhihua Institute of Iron and Steel Research , Ministry of Metallurgical Industry , Panzhihua , China associate professor , Institute of Metal Research , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

The determination of dffusible hydrogen in U71Mn heavy rail steel,and hydrogen diffusivity as well as the hydrogen distribution in the cross section of blooms with stack cooling were stu- died.The results showed that,most of the hydrogen in blooms of heavv rail steel is diffusible, the hydrogen diffusivity in U71Mn rail steel blooms at room temperature is(0.85—1.02)× 10~(-6)cm~2/s,after stack cooling,the hydrogen content in bloom will decrease greatly which is helpful to form the flake-free phenomenon in the heavy rail produced by Panzhihua Iron and Steel Company.

关键词: rail steel , null , null , null

Demand of Electric Power and Its Forecasting in Iron and Steel Complex

钢铁研究学报(英文版)

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