钢铁钒钛

Technical Analysis on Smelting Reduction Ironmaking Process

Guo Peimin, Zhao Pei, Pang Jianming, Cao Chaozhen

2009, 30(3): 1-9.

Abstract(32) PDF(1)

Abstract:
Main smelting reduction ironmaking processes were analyzed.COREX process,a pre-reduction shaft furnace + gasifier pure oxygen-bowing process,has been put into industrial production.~250 kg coke and ~1 000 kg fuel are needed for producing 1 ton hot metal.FINEX process,a multi-step fluidized bed + hot briquetting +gasifier +CO₂ absorbing pure oxygen-bowing process,can use ore fines,and its consumption of coke and fuel are ~200 kg and 800 kg per ton hot metal respectively.However,FINEX process is very complex,low efficient and still in the stage of industrial experiment.HISMELT tries to reduce and smelt ore fines by one-step process,but it is difficult for the process to realize the anticipated targets,and the process is still in the stage of technical research.So,present smelting reduction process can not realize low energy consumption and mild pollution ironmaking process,the key problem is the poor deoxidation properties of ore at low temperature.Improving deoxidation properties of ore can help smelting reduction process obtaining success,efficacy and good environment.

The New Direction of Comprehensive Utilization of High Titanium-bearing Slag

Li Xinghua, Wang Xuesong, Liu Zhilu, Zhang Jiangping

2009, 30(3): 10-16.

Abstract(23) PDF(3)

Abstract:
According to mineral characteristics and phase structure of high titanium-bearing slag,research progress on comprehensive utilization of the high titanium-bearing slag is reviewed.Six principles for the use of high-value of high-titanium slag are proposed.It is pointed out that the high-temperature carbonization and low temperature selective chloride,extraction of titanium by plasma smelting reduction and metallurgy modified selective precipitation separation are the direction of utilization of the high titanium-bearing slag in the future.

Discussion on Scientific Sustainable Development of Vanadium and Titanium Industry in Panzhihua

Qiu Kehui, Gong Yingchun, Zhang Peicong, Zhou Shijie

2009, 30(3): 17-20.

Abstract(18) PDF(1)

Abstract:
The characteristics of vanadium-titanium magnetite resources and the existing problems during the rapid development of vanadium titanium industry were investigated in the paper.The large quantities of gangue,tail sand,iron and steel slag have been produced by mining,ore dressing and iron making processing since 1970s.The importance,the environmental impact and the science and technique problems of multipurpose use of these industrial solid wastes as second resources were discussed in detail.Suggestions were proposed in the paper that the science sustainable development of vanadium titanium industries would be realized by reformation of traditional industries,further promotion advanced vanadium titanium materials industries such as vanadate rare earth phosphors in Panzhihua.

Experimental Research on the Ion Exchange of Vanadiferous Leaching Solution and Residual Solution Recycling

Fu Zibi, Zhang Lin, Zhang Tao

2009, 30(3): 21-25.

Abstract(19) PDF(1)

Abstract:
Based on the clinker of calcifying roasting of stone coal in Hubei Province,the experimental processes involving the acid leaching of roasted clinker,leaching solution impurity removal,ion exchange,supplement to residual solution by sulfuric acid leaching,leaching solution impurity removal again,which had been recycled 12 times,were researched.The concentration of SiO₂,P,Cl^-,SO₄^2-,Na⁺ in residual solution and the variation of leaching percentage of vanadium alone with the recycling times increasing were investigated.The research result indicated that the recycling use of residual solution would not affect the leaching percentage of vanadium significantly,no enrichment of SiO₂ in the solution,certain concentration of P,SO₄^2-,and Na⁺.P and SO₄^2- could be precipitated and removed by lime-neutralization,and Na⁺ would get dynamic balance in the solution and would not affect its recycle.

Simulation Study on Compositions and Process Optimization of V-microalloyed N80-class Seamless Tube

Xue Dongmei, Pan Tao, Zhao Sujuan, Wang Qingfeng, Yang Caifu, Zhang Yongquan

2009, 30(3): 26-32,37.

Abstract(22) PDF(1)

Abstract:
The synthesis effects of different nitrogen(N) contents and thermal processes on the microstructure and mechanical properties of 33Mn2V steel for N80-class seamless tube were investigated using Gleeble simulation technique.The results showed that when the N content in the steel increased from 0.005% to 0.014% or 0.021%,for in-line normalizing process,the strength of steel increased,and in the same time toughness of steel increased greatly.The further research showed that while the reheating temperature decreased,the strength of steel became lower slightly and the toughness of it improved.When the cooling-interrupted temperature of steel changed from 450 ℃ to 700 ℃,the process varied from in-line normalizing to non in-line,which made the strength of steel increased significantly and the toughness decreased evidently.This can be attributed to the dissolution and precipitation behavior of V(CN).The optimization of V(CN) precipitation can be achieved by the enhanced N.

Research on Mechanical Properties of Low-carbon Microalloyed Steel Added with Micron-grade ZrC Particles

Huang Zhongdong, Niu Jianping, Cai Qingkui, Huang Wenli

2009, 30(3): 33-37.

Abstract(20) PDF(1)

Abstract:
In vacuum conditions,micron-grade ZrC ceramic particles with 1.1% volume fraction were added into low-carbon microalloyed steel.The steel was hot-rolled in Φ450 mm experimental hot mill.The steel grains were refined to 5.5 μm after hot rolling.The tensile strength and yield strength of the hot rolled steel were 635 MPa and 517.5 MPa respectively,and its HV hardness(HV5) was 214.ZrC particles can strengthen the steel obviously,and can also refine the grains of the steel in the course of crystallizing and solidifying of the steel and during hot-rolling process afterwards.The microstructure of the hot rolled steel is ferrite.Inclusions are dispersed in the steel.

Change of the Non-metallic Inclusions during the Secondary Refining of Low Oxygen Alloyed Structural Steels

Zhao Kewen, Wang Xinhua, Li Haibo, Wang Ying, Chen Tianming

2009, 30(3): 38-43.

Abstract(23) PDF(1)

Abstract:
Slag of high basicity and high Al₂O₃ content was used in secondary refining of alloyed structural steels aiming at decreasing total oxygen contents(T[O]) of steel and forming relatively lower melting point inclusions to improve the anti-fatigue properties of the steels.It was found that T[O] at the end of LF and RH refining both decreased with the increase of slag basicity.When Al₂O₃ in the slag was less than 25%,T[O] decreased with the decrease of Al₂O₃ content of slag.While,when Al₂O₃ in the slag was more than 25%, T[O] decreased with the increase of Al₂O₃ content of slag.In the refining,compositions of the non-metallic inclusions changed in order of "inclusions of Al₂O₃ → inclusions of MgO-Al₂O₃ system → inclusions of CaO-MgO-Al₂O₃ system",among which,the change of inclusions of MgO-Al₂O₃ system to was inwardly from outside surface and the reaction speed was relatively slower.Thus,at the end of the ladle furnace refining(LF),there were still many unchanged MgO-Al₂O₃ system inclusions.The T[O] content of the steels significantly affects the composition change of the inclusions and decreasing T[O] content could help obtain inclusions of CaO-MgO-Al₂O₃ system with low melting point.

Research on the Non-metallic Inclusion in X70 Pipeline Cast Slab

Wu Yuchen, Li Junguo, Yan Xiaolin, Li Shouzhang, Ceng Yanan

2009, 30(3): 44-49.

Abstract(22) PDF(1)

Abstract:
Utilizing the methods of sample-electrolysing,metallographic observation,SEM and EPMA,the quantity,dimension,morphologies and composition of non-metallic inclusions in X70 pipeline steel cast slab were investigated.It was suggested that there were larger amount of inclusions with larger diameter in the cast slab.Most of these inclusions were complex,such as sulfide,oxide,silicon aluminates and calcium aluminates inclusions.According to the characteristics of inclusions in the cast slab,the major sources of different inclusions were analyzed and explored.

Technology of High Efficient Slab Caster at PISCO

Chen Yong, Xiao Mingfu, Wu Guorong, Yang Subo, Ceng Jianhua

2009, 30(3): 50-55.

Abstract(18) PDF(1)

Abstract:
Technologies of high efficient slab caster and its application effect at PISCO(Panzhihua Iron & Steel Co.) were presented.The casting speed was increased to the range between 1.30 m/min and 1.80 m/min owing to developing reasonable mold flux,primary cooling scheme and molten steel temperature control.The rate of sliver defect on cold-rolled sheet was decreased from 10.97% to 1% due to adjusting compositions and performance of steel slag,optimizing refining process,and designing high viscosity flux.Meanwhile,the mean operating rate of slab caster was increased from 89.39% to 92.96% benefit from reasonable distributing function between two slab casters,applying quick exchanging for nozzle,reducing reheating time of molten steel at LF,and improving production capacity of RH.These achievements have provided important technology supports for PISCO to obtain 154 million tons product of continuously cast slab in half a year of 2008.

Influence of Basicity on Microstructure of Vanadium-titanium Magnetite Sinter

Han Xiuli, Wang Haifeng, Liu Lina, Yao Mingyan, Wang Yanhong

2009, 30(3): 56-60.

Abstract(29) PDF(1)

Abstract:
The influences of basicity on microstructure of vanadium-titanium magnetite sinter were studied by optical microscopy.The results showed that when basicity is increased from 2.1 to 2.5,the content of titanomagnetite,calcium ferrite and dicalcium silicate increase,but the content of titanohematite and glassiness decrease;The content of the skeletal hematite and the wrapping texture decrease,the structure of the sinter turns from porphyritic structure to interweaving corroded;the corresponding strength of the sinter is increasing.When basicity is 2.5,the form of calcium ferrite is stylolitic or acicular,the form of titanomagnetite is xenomorphic granular,the form of perovskite is crisscross or xenotopic.

Effect of Different Deoxidizer on the Cleanliness of Gas Bottle Steels

Yang Shufeng, Li Jingshe, Zhang Lifeng, Tang Haiyan, Gao Jinguo, Jiang Guilian

2009, 30(3): 61-64.

Abstract(27) PDF(1)

Abstract:
The current study investigated the effect of two different deoxidizers on the composition and number of micro-inclusions and macro-inclusions,and the total oxygen content(T[O]) in the gas bottle steels.Using Si-Ca-Ba-Mg-Sr alloy as a deoxidizer decreased the number of micro-inclusions and macro-inclusions,and the inclusions of alumina and Al₂O₃-CaO in the billet,while increased inclusions of sulfides and SiO₂-Al₂O₃-CaO.The different deoxidizers affected little on the T[O] which all can be controlled below 12×10^-6.The yield of Si-Ca-Ba-Mg-Sr alloy as a deoxidizer should be improved in the future studies.

Numerical Simulation of Comprehensive Metallurgical Behavior of Liquid Steel in Slab Mold

Xiao Niangen, Ni Shengqi, Fu Huijie

2009, 30(3): 65-69,75.

Abstract(17) PDF(1)

Abstract:
Numerical simulation of comprehensive metallurgical behavior of liquid steel in slab mold is described.It was found that the flow of liquid steel was decided by the shape and intensity of the jet of SEN.Under the condition of working tip structure of SEN used,the low pressure back flow zone near the side port of SEN result in the liquid steel outflow from the bottom of the sides port and the effective area of sides port became lower.The big fracture surface made the temperature of meniscus get low.The temperature of shell got low with the fracture surface increase.When the size of fracture surface is 1 400 mm×230 mm and 1 600 mm×230 mm,the thickness of narrow side solidification shell of mold outlet is 11.5 mm;the size of fracture surface is 1 800 mm×230 mm,the thickness of narrow side solidification shell of mold outlet is 13.4 mm.The fracture surface has little effect on the thickness of shell of wide sides.

Thermal-mechanical Coupled Analysis for Copper-steel Cooling Stave

Liu Zengxun, Chen Xiaoming, Yan Lifeng, Niu Jianping

2009, 30(3): 70-75.

Abstract(14) PDF(1)

Abstract:
The heat transfer and thermal stress model for copper-steel colling stave is established by ANSYS.The temperature and thermal stress distribution of the stave is analyzed when the slag skull is steady and after the slag skull drops off.The result shows that gas temperature is the main factor that affects stave temperature and slag skull thickness and heat load and stress distribution.In the steady condition,the maximum of temperature on the copper plate is 124 ℃ and the heat load is 81.1 kW/m².The distortion is smaller than copper stave.After the slag skull drops off,temperature and stress on the copper plate increase rapidly.The temperature and stress state trend to stability when slag-drop time is 5 minutes.The copper plate and steel plate are combined firmly each other in the slag-drop state.

Finite Element Analysis of Tracked Steel’s Rolling Process

Tao Gongming

2009, 30(3): 76-79.

Abstract(14) PDF(1)

Abstract:
The tracked steel's section is very complex.The phenomena of torsion and warpage often happen,which affects the tracked steel's rolling process.The finite element model of tracked steel's rolling process in the knifing pass was established.The influences of the pass parameters upon the rolled piece's torsion and warpage were studied.On the basis,the pass parameters were optimized.The study made the torsion angle reduce from 135.6° to 13.85°,which ensured the succeeding pass rolling processes.

Optimization of Slab’s Reheating Process

Liu Yong, Wen Yacheng, Li Weiping, She Guangfu, Li Junhong, Lin Xia

2009, 30(3): 80-83.

Abstract(23) PDF(1)

Abstract:
A mathematical model for slabs heated in a 3-zone walking beam type of reheating furnace was established.The finite difference method was used for the discretion of the mathematical model and a computational software was developed.The influence of the slab's width on the change of the slab's temperature was studied.It was founded that,to the 200 mm thick slab,when the width is above 600 mm,the slab's width has no influence on the slab's center point temperature.According to the result,the slab's reheating process was optimized,which improved the productivity and saved the energy.

Research on Quality Control of 45^# Steel Billet

Yu Jie, Tang Ping, Yang Hao, Wen Guanghua, Hu Daofeng, Zhang Yue, Ma Jun

2009, 30(3): 84-88.

Abstract(17) PDF(1)

Abstract:
According to the problem of internal cracks occurred on continuous casting billet at Nanjing Iron & Steel Co.,Ltd.,the species,quantity and size of inclusions on the different position of billet cross section were statistically analyzed.The results showed that: main causes of internal cracks are large sulfide inclusions and large temperature recovery.Through the secondary cooling numerical simulation and the production practice,it proved that the optimization of secondary cooling scheme can be used to control solidification performance of inclusions of billet,reduce segregation and quantity of sulfide in billet.So the internal cracks of billet can be controlled efficiently.

Discussing on Increasing the Utilization Rate of Titanium in Panzhihua Mineral Resources

Gou Shuyun

2009, 30(3): 89-92.

Abstract(25) PDF(2)

Abstract:
According to the Panzhihua municipality's "Turning Panzhihua into China's Vanadium-titanium Capital,Establishing Distinctive Economy System"developing strategy,the utilization state of Ti in Panzhihua vanadium-bearing titaniferous magnetite is presented.Since the utilization ratie of Ti resource is low compared with that of Fe and V,the developing status and technical advantages of conventional blast furnace smelting and direct reduction process for increasing the utilization ratie of Ti is discussed.In order to overcome the technology difficulty for industrial-scale uses of Ti in Panzhihua vanadium-bearing titaniferous magnetite,the suggestion of how to develop Panzhihua titanium industry effectively by takeing advantage of the technique we owned at present is put forward.

2009 Vol. 30, No. 3