钢铁钒钛

DENG Guo-zhu, WANG Xiang-dong, CHE Xiao-kui

2003, 24(1): 1-7.

Abstract(46) PDF(2)

Abstract:
This paper describes the outline of titanium mineral resources in the world. The production of titanium mineral feedstocks,titanium dioxide and titanium metal are discussed. Measures are proposed to promote the advance of titanium industry in China against the situation of China joins WTO. The author sets forth a series of technological view, which includes strengthening the post-treatment research of titanium dioxide, proving the product quality of titanium dioxide produced by sulphate process, speeding up the technical study and industrialization of chloride process to gradually reduce the imports of titanium dioxide in high quality from oversea, progressing the development of titanium metal etc.

THERMODYNAMICS AND KINETICS OF PRODUCING SYNTHETIC RUTILE BY SELECTIVE CHLORINATION OF ILMENITE

WEN Wang-guang

2003, 24(1): 8-15.

Abstract(45) PDF(1)

Abstract:
The phase equilibrium diagram of Fe-Ti-C-O₂-Cl₂ system is studied for the preparation of synthetic rutile by selective chlorination of ilmenite. The changes of free energy are calculated in the reactions between O₂ and certain chlorides. By means of a process-"oxygen-induction one-step selective chlorinatio", the key technical problem is solved which requires a continuous process for "self-heating" chlorination. The technical parameters have been verified by lab-test, pilot test and industrial-scale test. The study has proved that the dynamic model of the selective chlorination process is a "shrinking core reaction model in which the solids' particle size is kept unchanged", with the activation energy in the dynamic zone being 34.33 kJ/mol and that in the diffusion zone 0.8 kJ/mol. The fluidized bed chlorinator without perforated-plate developed in this process can stably and continuously operate in a long period of time. The process and the relevant equipment have been successfully applied in the industrial production, with the grade of resultant synthetic rutile being 92.1%, and even up to 95% through the additional table concentration and magnetic separation. The reactor's capacity can reach 12.4 t/m²·d.

PERFORMANCE RESEARCH OF U71Mn 75 kg/m HEAVY RAIL STEEL

JI Fei-fei

2003, 24(1): 16-20.

Abstract(44) PDF(1)

Abstract:
The isothermal transformation curve and continuous cooling curve of U71Mn 75 kg/m heavy rail steel were measured. According to the results of isothermal transformation and continuous cooling transformation, the optimal eutectoid structure in the heavy rail steel could form when the cooling velocity was controlled between 2℃/s and 8℃/s. The comparison tests of U71Mn 75 kg/m steel and U74 60 kg/m steel show that the load capacity of the former is 1.3 times larger than that of the later while the practical fatigue strength is approximate, and the impact toughness of the former is better than that of the later with the same impact force.

DEVELOPMENT OF NON-ALUMINIUM DEOXIDIZING TECHNOLOGY FOR RAIL STEEL

LI Gui-jun

2003, 24(1): 21-24.

Abstract(52) PDF(1)

Abstract:
It is introduced that the development and application of non-aluminum deoxidizing technology for rail steel in PZH Steel. Combining pre-deoxidizing technology with final-deoxidizing process, the internal quality of rail steel was greatly improved, and finally come up to 200 km/h high-speed rail standards.

STUDY ON CONDUCTIBILITY OF Fe-Ti-C GREEN COMPACT

YANG Yi, FENG Ke-qin, GUO Lu-bao, WANG Yu-cheng, SHEN Kai-zhi

2003, 24(1): 25-28.

Abstract(70) PDF(4)

Abstract:
The factors that affect the conductibility of green compact were analyzed. In order to study the effects of composition on conductibility, the compacts with 0%Ti, 20%Ti, 32%Ti, 44%Ti, 56%Ti were made up. The blocks were vacuum-sintered at 1 250℃ for studying the difference of conductibility of compacts after sintering. The result shows that the conductibility of green compact goes down with the increase of compact porosity and Ti content. At mean time, the change of compact in conductibility and sizes after sintering at 1 250℃ could be explained by Kirkendall effect.

CONTROL FOR CREEP DEFORMATION OF CONVERTER SHELL

REN Xue-ping, GUO Zhi-qiang, ZOU Jia-xiang

2003, 24(1): 29-32,38.

Abstract(41) PDF(1)

Abstract:
The temperature of converter shell rises sharply with the utilization of MgO-C brick lining,it results in the shell permanent deformation.Research shows that the shell pemanent deformation is creep deformation but not plastic deformation.The factors of affection the creep deformation are presented,and the technical measures controlling the shell creep deformation are put forward.

APPLICATION OF HEATING TECHNOLOGY OF BILLET FOR HOT ROLLED RAILS AT PZH STEEL

CHEN Yong

2003, 24(1): 33-38.

Abstract(52) PDF(1)

Abstract:
Current thermal characteristics of push-type furnace and heating technique of billet for heavy rail was evaluated based on the experiments of embedding thermal couples and determining energy balance. On the basis, the heating technique and the thermal schedule were optimized. The productive operation shows that the fluctuation of billet temperature is lowered from ±40℃ to ±20℃, difference in billet profile temperature is lessened from 65℃ to 45℃, the loss of metal oxidation is reduced from 1.755% to 0.92%, and the decarburization depth of rails is decreased from 0.35~0.82 mm to 0.2~0.5 mm, while, the annual production of heavy rail is increased from 400,000 tons to 500,000 tons.

STUDY ON DIGESTION TECHNOLOGY OF ACID-DISSOLVED TITANIUM SLAG

ZHANG Shu-li, CHENG Xiao-zhe, HU Hong-fei

2003, 24(1): 39-45.

Abstract(44) PDF(3)

Abstract:
According to the properties of titanium slag produced from the smelting of Panzhihua ilmenite, the affecting factors of titanium slag digestion efficiency and titanium liquor properties were investigated by laboratory test. Based on the results, industrial experiments were taken on the 2 000 t/a titanium dioxide production plant and the technical process was optimized. The digestion efficiency of titanium slag come up to above 93.0%, the Ti³⁺ content is 1~3 g/L, the concentration of TiO₂ is higher 40~50 g/L than ilmenite digestion, and the technical indexes of titanium liquor are satisfied for the hydrolysis process.

RESEARCH ON REDUCTION AND NITROGENIZATION PROCESS FOR PREPARING VN FROM V₂O₅

XU Xian-feng, WANG Xi-tang

2003, 24(1): 46-49.

Abstract(54) PDF(1)

Abstract:
The theoretical analysis and experimental investigation have been taken for the reduction process of preparation VN with C and V₂O₅. The results show that both direct reduction and indirect reduction take place during the reduction process of V₂O₅, in which the VN formed with high-temperature- nitrogenization changes into VC. With the experimental conditions, the beginning reaction temperature of direct reduction is 656 K, the nitrogenization occurs at 1 160 K, and VN translates into VC at 1 560 K. The indirect reducing reaction is related to the ratio of mixture, with the increase of carbon ratio there occurs increase in possibility of reducing reaction.

INVESTIGATION IN TECHNOLOGY AND PARAMETER FOR VACUUM-CRYSTALLIZATION-SYSTEM

WANG Guo-ping, XIAO Yong-hua

2003, 24(1): 50-53.

Abstract(65) PDF(3)

Abstract:
The characteristics of two technologies in vacuum-crystallization-system were discussed during the production process of titanium dioxide with sulphate process. The crystallizing behaviours of ferrous sulphate were investigated in vacuum-crystallization-system. It is concluded that adopting two-step steam- spraying process enables the steam sprayer to work in optimum conditions. The optimization of technological parameter of steam sprayer was inquired.

APPLICAION OF FINITE ELEMENT ANALYSIS AND SIMULATION TECHNIQUE TO SHEET METAL FORMING

QIU Xiao-gang, LU Guo-qing, CHEN Wen-long, LUO Zhong-yun

2003, 24(1): 54-60.

Abstract(48) PDF(1)

Abstract:
The development and key techniques of finite element analysis (FEA) for sheet metal forming are introduced.The FEA calculation to deep drawing parts is carried out by dynamic explicit software DYNAFORM.The calculated results are in good accordance with the experimental results,and it is the foundation for finite element simulation.

ANALYSIS OF FORMING REASONS FOR TRIANGULAR CRACK ON CONTINUOUSLY CAST SLABS AT NANGANG

MEI Feng, WEN Guang-hua, TANG Ping, JIA Ning-chen, HU Dao-feng, LI Xiang, MA Jun, ZHANG Yue

2003, 24(1): 61-65.

Abstract(68) PDF(1)

Abstract:
According to the current status of triangular area cracks occurring on continuously cast slabs at Nanjing Iron & Steel Co.,LTD., the exact position and type of the triangular area crack were obtained by macroscopic structure and sulphur print test. On the basis of the model of cooling water distribution in secondary zone at Nangang, the forming reasons of triangular area crack on slab were analyzed and the corresponding improvement measures were put forward. After adopting the improvement measures, the ratio of slabs occurring triangular crack decreased to 2.33%.

DEVELOPING OF NON-QUENCHED AND TEMPERED BAINITIC STEEL

HU Shu-e, TANG Li-dong, FENG Yong, WANG Xiang-bin

2003, 24(1): 66-70.

Abstract(57) PDF(2)

Abstract:
In order to decrease the product cost, a newly high strength bainitic steel have been developed. This steel is a plain carbon structural steel, its advantage is using cheap V, Mn, Cr instead of expensive Ni, Mo, B and other elements for alloying. The heat treatment of steel is not needed, so the production process is simply. The heating and rolling schedule are similar with other steels, but adopting controlled rolling and air cooling increase the strength and toughness. The tensile strength of experimental steel plates is higher than 860 MPa, and the impact toughness is improved with the decreasing of end rolling temperature.

DU Hou-yi

2003, 24(1): 71-74.

Abstract(55) PDF(2)

Abstract:

2003 Vol. 24, No. 1