钢铁钒钛

Activity Model and Its Application of Quarternary System CaO-FeO-SiO₂-V₂O₃

Guo Peimin, Zhao Pei

2005, 26(3): 1-6.

Abstract(16) PDF(1)

Abstract:
The activity model of quarternary system CaO-FeO-SiO₂-V₂O₃ was established according to the coexistence theory of slag structure.The results show that the activity coefficient of V₂O₃ in slag is in good accordance with experimental data.On the other hand,activity coefficient of V₂O₃ depends on the basicity and oxidizability of slag.The yield of vanadium depends on the steel composition,slag composition and slag quantity.The slag quantity and oxidizability have remarkable effects on the yield during making vanadium steel.Among some additives such as ferrovanadium,V₂O₅ and vanadium slag,the best yield of vanadium comes from ferrovanadium,while the poorest one is vanadium slag,which can be only used for microalloy vanadium steels.

Precipitation Harding of V(C,N) in High Vanadium Steels

Xu Man, Sun Xinjun, Liu Qingyou, Dong Han, Yong Qilong, Huang Jinliang

2005, 26(3): 7-11.

Abstract(23) PDF(1)

Abstract:
The micro-structure and mechanical properties of three high vanadium steels rolled in laboratory were investigated.The precipitation of V(C,N) was studied through TEM.The results showed that the single-phase ferrite matrix microstructure and high yield strength could be obtained.Carbon was completely combined with vanadium in the experimental steels,so single-phase ferrite and the optimal precipitation hardening effect was acquired.The maximal yield strength of test steel was 525 MPa.The maximal increase of strength caused by V(C,N) precipitates was 244 MPa for C3 steel.The interphase precipitation is easy obtained in high vanadium steels and the diameter of V(C,N) is about 4~10 nm.

Theoretical Calculation for Equilibrium Solubilities and Compositional Coefficient of Titanium Carbonitrides in Ti-bearing Microalloyed Steel

Yong Qilong, Liu Zhengdong, Sun Xinjun, Cao Jianchun, Zhao Kunyu, Zhang Yong, Cha Xiaoqin

2005, 26(3): 12-16.

Abstract(33) PDF(1)

Abstract:
According to the thermal-mechanical theory and the solubility formulae of TiN and TiC in austenite,the theoretical calculating methods for the solubility of Ti,C and N in austenite and for the compositional coefficient of Ti(C,N) in Ti-bearing microalloyed steel were proposed.The calculations for the typical Ti-bearing steels were carried out.and the calculating results show that the titanium carbonitrides undissolved or precipitated at high temperature are very similar to the pure TiN.

Synthesis Effect of Manganese and Finish Rolling Temperature on High Nitrogen Vanadium Microalloyed Steels

Wang Zhengbao, Liu Jing, Sun Qunfeng, Yuan Zexi

2005, 26(3): 17-19,36.

Abstract(18) PDF(1)

Abstract:
The synthesis effect of manganese and finish rolling temperature on high nitrogen vanadium microalloyed steel was investigated by testing the mechanical properties,examining the microstructure and the precipitation of carbo-nitride by use of SEM and TEM.The results show that the high manganese content can compensate the unfavorable influence of high finish rolling temperature on fine microstructure,while the high finish rolling temperature can eliminate the unfavorable influence of high manganese on precipitation strengthening,wherefore the high manganese as well as high finish rolling temperature is good at fine microstructure and precipitation strengthening.

Study on Deformation and Densification of Powder Upsettingfor Fe-based Sintered Porous Material

Li Yongzhi, Song Shihua, Yu Shihao

2005, 26(3): 20-23.

Abstract(15) PDF(1)

Abstract:
The deformation and densification law of powder forging was studied for Fe-based sintered porous material.The local strain limit criterion for the cracking on surface was achieved,and the process parameters of forming limit were obtained for the cracking limitation based on experimental results of powder forging for Fe-based porous material with different initial conditions,which include friction factor,relative height and relative density.With the experimental results,the design of mould and green compact of sintered porous material can be optimized.

Research on New Technology of Making High-grade Titanium-rich Material from Self-reduced Pellet of Titanium Concentrate by Microwave Reduction

Huang Mengyang, Peng Jinhui, Zhang Shimin, Sun Yan, Wang Yunhua, Huang Ming, Fan Xingxiang

2005, 26(3): 24-28.

Abstract(24) PDF(2)

Abstract:
A new technology for preparing rich titanium product,which includes microwave reduction-mineral separation-microwave leaching,was put forward on the basis of the abundant situation of titanium mineral resource in Panzhihua-Xichang zone and the advantages and disadvantages of actual productive methods on making rich titanium product.The heating curve of self-reduced pellet of titanium concentrate was measured.The appropriate technological parameters including the content of additive 5%~6%,the milling time of 20 min were determined.Experiments were conducted on the whole flow sheet and the TiO₂ content in titanium rich product was 96.08% under the above condition.

Study on Modifiers for Impurities Removal in Microwave Leaching of Titanium Material

Sun Yan, Peng Jinhui, Huang Mengyang, Zhang Shimin, Xie Kongming, Fan Xingxiang, Zhu Yanli

2005, 26(3): 29-32.

Abstract(15) PDF(1)

Abstract:
A new modifier was developed.It could be used in microwave leaching course to remove impurities such as Ca and Mg for preparing rich titanium material from titanium material.The systemic conditional experiments were conducted on the flow sheet.It was showed that adding the modifier in microwave leaching course could raise leaching rates of the impurities.The leaching rate of impurities was as follows:CaO 96.96%,MgO 99.79%,and TFe 93.05%.The optimum technological parameters include selecting modifier B,its content 10%,and 90 min leaching time.The content of TiO₂ of rich titanium material could reach 94.89% under the optimum conditions.

Industrial Experiment of Producing Titanium White by Acid Dissolved Titanium Slag

Zhang Shuli

2005, 26(3): 33-36.

Abstract(12) PDF(1)

Abstract:
Based on the optimal technical parameters from laboratory experiment,the industrial experiment was carried out on the 2 000 t/a titanium white production plant by acid dissolved titanium slag.The digestion ratio is 92.56%,the hydrolysis ratio is more than 95%,the ratio of up to grade product is 100%,and the ratio of high grade is 75%.The results met the manufacturer's claimed technical requirements and quality level.The production capacity of titanium white by acid dissolved titanium slag is increased compared with use titanium concentrate.On these grounds,the technology of producing titanium white by acid dissolved titanium slag could be put into industrial operation.

Effects of Magnetic Field and Electric Field on the Microstructure and Properties of Metal Materials During Heat Processes

Cheng Xingde, Wang Minli, Zhang Kaijian, Shi Qingnan

2005, 26(3): 37-43,63.

Abstract(37) PDF(1)

Abstract:
The research on the evolution of micro structure and properties of metal materials under magnetic field and electric field during heat processed was reviewed in detail.The magnetic field and electric field have evident effects on the micro structure and properties of metal materials.the magnetic field and electric field can make the grain finer of metal materials during heat processes.Besides,the capability of conduction and heat transfer of metal materials can be improved,and the cooling uniformity of metal materials and the strength after aging can be improved in the magnetic field.The strength,harden and osmosis of metal materials can be improved in the electric field.

Recent Development of Research on Soft-contact Electromagnetic Continuous Casting of Japan

Yang Jian, Chen Chongfeng

2005, 26(3): 44-47,63.

Abstract(23) PDF(1)

Abstract:
The principle of soft-contact electromagnetic continuous casting and the recent research development in Japanese were introduced.The influence of coil current,Joule heat,the shape of the mold and the early-solidified shell on surface quality of strand was discussed.The problems that should be noticed in future were presented.The following views are concluded.The Joule heat produced by induction coil is the chief influence factor of strand surface quality.There is an optimum coil current,otherwise,it would have unfavorable effect on the surface quality of strand.With same technological parameters,the surface quality of strand produced by round angle mould is better than by right angle mould.

Formulate Rolling Schedule of Strip Steel Based on EXCEL Calculator

Lu: Lihua, Liu Weiguang, Ma Jinjiang, Lin Jun, Zhang Yongwei

2005, 26(3): 48-52.

Abstract(13) PDF(1)

Abstract:
The basic methods and development trend of formulating rolling schedule were summarized.How to optimize the rolling schedule using EXCEL calculator was introduced under the conditions with multi-goals and multiple restrictions.The main mathematical models involved in the optimizing calculating were discussed, and the optimizing effect was explained by instances.This method is suitable for technicians to practical operation, it is also useful for increasing production efficiency of strip steel and giving full play to the ability of the equipment etc.

Optimizing Heat Schedule of Billet in Reheating Furnace

Xue Nianfu, Li Li, Qi Shuangyang

2005, 26(3): 53-59.

Abstract(21) PDF(1)

Abstract:
The temperature distribution of continuous casting billet in reheating furnace was measured under practical operation.The economic range of operation load for reheating furnace was determined,and the one-dimension stable-state mathematic model of billet reheating course in pusher-type reheating furnace was established.The temperature distribution of continuous casting billet in reheating furnace was calculated and analyzed based on the measured results and mathematic model.A optimum heat schedule of billet in reheating furnace was presented.The practical operation of new heat schedule show following results:the gas consume of reheating furnace reduce 5.3%,the temperature difference along the length of billet decrease 10℃,and the temperature difference along the cross section of billet is 38℃.

Design and Application of Oxygen Lance for Converter Steelmaking with Semi-steel at PZH Steel

Xu Lizhi

2005, 26(3): 60-63.

Abstract(23) PDF(1)

Abstract:
According to the characteristics of steelmaking with semi-steel at PZH Steel,the structure and spray nozzle of oxygen lance for high supply intensity were discussed.The new type oxygen lance has 5 jets,and the jets are arranged on the same circumference of spray nozzle end.The shape of jet is similar to Laval-shape,and the dip angles are 13° and 15° respectively.The throat diameter is 35 mm.The metallurgical effects of new designed oxygen lance were obvious.It shortened oxygen blowing time 2.6 min/heat,meanwhile,the blowing process was smooth,the need of lining protection by slag splashing was satisfied,and the technical-and-economic indexes were improved.

A New Method to Analyze Nitrogen Content of VN Alloy

Wang Peng, Yang Fan, Li Hongwei, Ma Hongquan, Wang Haizhou

2005, 26(3): 64-68.

Abstract(25) PDF(1)

Abstract:
Methods to analyze the nitrogen content of vanadium-nitrogen alloy were discussed with ON2008 oxygen and nitrogen analyzer(made in China).Referred to the reported documents,a new simplified method was presented.The new method chose argon as the carrying gas,no flux is needed,the sample is directly put into the crucible,and a graphite cover designed specially is used.The new method cut down the analyzing cost and simplifies the preparation of sample,the weighing of sample could be more than 0.1 g.The method was applied in the analysis of VN production,and the accuracy of result could match the requirement.

Wang Yuansun

2005, 26(3): 69-70.

Abstract(19) PDF(1)

Abstract:

2005 Vol. 26, No. 3