钢铁钒钛

Progress in Japan’s Titanium Metal Preparation Technologies

Li Liang, Yang Baoxiang, Luo Jingli, Liu Dachun

2017, 38(2): 1-10. doi: 10.7513/j.issn.1004-7638.2017.02.001

Abstract(28) PDF(3)

Abstract:
The progresses of Japan’s titanium metal preparation technologies in recent years,such as preparation of titanium sponge,new titanium metal extraction technologies,titanium scrap recovery and purification,were summarized in this paper. The technical progresses in adjustment of raw materials structure,enhancement of single furnace production capacity,purity improvement of raw material （TiCl₄ and Mg） and quality amelioration of titanium sponge,made by Osaka Titanium Technologies Co.,Ltd.and Toho Titanium Industry Co.,Ltd.in preparation of titanium sponge,were emphatically introduced.The use ratio of titanium material containing 90%~92% TiO₂ is more than 30%.Titanium sponge production capacity of single furnace has reached to 13 tons.The stable production and preparation process of high purity titanium has been established by Kroll process and the purity of titanium metal is 99.999% （5N9）.Alternative titanium metal extraction technologies to lower the production costs,which include OS （calcium thermic reduction）process,electronically mediated reaction and molten salt electrolysis （EMR/MSE process）,preformed reduction process （PRP process）,and their technical characteristics were discussed. Recovery of titanium metal scrap for TiCl₄ preparation and direct oxygen removal technique utilizing MgCl₂ molten salt electrolysis of titanium metal scrap were also reviewed.The technology feasibility of new methods was proved by theories and experiments,but further studies,such as simplifying the equipment,improving production efficiency and product purity,still need to be conducted for replacing the Kroll process.

Study on Carbothermal Sodium Reduction Process of Vanadium-titanium Magnetite Concentrate

Chen Qianye, Zhang Jun, Cheng Xiangkui, Yan Dinliu, Qi Yuanhong

2017, 38(2): 11-15. doi: 10.7513/j.issn.1004-7638.2017.02.002

Abstract(17) PDF(1)

Abstract:
In order to realize the comprehensive utilization of vanadium-titanium magnetite concentrate at lower temperature,carbothermal sodium-treatment was adopted to reduce the reduction and smelting-separation temperatures,and the enrichment recycling of iron,vanadium as well as titanium was investigated.The sodium agent improves the reducibility and smelting-separation performance of the vanadium titanium magnetite concentrate significantly.The metallization ratio of the sample reduced at 1 100 ℃ for 60 min with a sodium ratio of 1.2 was higher than 90%,and the iron yield reached 96% with smelting-separation at 1 250℃ or higher and the enrichment ratio of vanadium in iron was 75%. Moreover,TiO₂ content in the slag reached 77% when the smelting-separated slag was treated by wet-process in acid free environment,which could be further enhanced when the iron is removed via the reduction and smelting-separation process.

Study on the Action Mechanism of Pre-oxidation on Reduction Behavior of Rock Ilmenite

Zhang Jianbo

2017, 38(2): 16-22. doi: 10.7513/j.issn.1004-7638.2017.02.003

Abstract(17) PDF(1)

Abstract:
Reduction is the key technological process of preparing titanium-rich material from ilmenite.This paper studied the action mechanism of pre-oxidation on reduction behavior of rock ilmenite in detail,using Panzhihua ilmenite as the experimental subject.The results show that the reduction rate of untreated rock ilmenite is slow and the pre-oxidation can increase the reduction rate effectively. This is due to the rapid transformation reaction of Fe³⁺→Fe²⁺ （FeTiO₃） at the earlier stage of reduction for pre-oxidized ilmenites.This rapid reaction produces a large number of pores and destroys the dense structure of ilmenite,which is conducive to the proceeding of reduction reaction.The rate of subsequent reduction of ilmenite is greater with higher pre-oxidation temperature and longer roasting time for pre-oxidation.Moreover,the preoxidation also makes the metallic Fe,which is produced by the subsequent reduction,have smaller grains and a more dispersed distribution.

Study on Separation Performance of V （Ⅳ） and Fe （Ⅲ） by P204 in Sulfuric Acid Extraction System

Feng Xueru, Lü Guozhi, Zhang Ting'an, Zhang Ying, Zhao Qiuyue, Liu Shuping

2017, 38(2): 23-29,36. doi: 10.7513/j.issn.1004-7638.2017.02.004

Abstract(22) PDF(4)

Abstract:
Aiming at the shortcomings of high energy consumption,heavy pollution and low recovery rate for the traditional vanadium production technologies,a new process for vanadium extraction by acid leaching using the waste acid in titanium white production under the pressure without roasting was proposed.In this paper,the leaching solution was taken as the research object. Component area map,orthogonal tests and single factor tests had been used to research the separation performance of V （Ⅳ） and Fe （Ⅲ） in P204 sulfuric acid extraction system.The experimental results show that V （Ⅳ） and Fe （Ⅲ） respectively exist in the main form of VO²⁺and Fe³⁺in aqueous solution when the pH is less than 2,and the phase ratio （O/A） is an important factor affecting the extraction rates of V （Ⅳ） and Fe （Ⅲ）.At the optimum extraction conditions of 30% P204+10% TBP +60% sulfonated kerosene for organic phase composition,extraction temperature T = 30 ℃,shaking for 8 min,1. 6 for the initial aqueous phase pH and phase ratio （O/A） = 3,the extraction rates of V （Ⅳ） and Fe （Ⅲ） are respectively 61.16% and 18.87%,with the separation factor of V （Ⅳ） and Fe （Ⅲ） at 6.67.

Numerical Simulation for Fluidized Chlorination Cold Model of High-titanium Slag in Yunnan

Zhu Kuisong, Liu Songli, Gou Shuyun, Wang Liang

2017, 38(2): 30-36. doi: 10.7513/j.issn.1004-7638.2017.02.005

Abstract(34) PDF(2)

Abstract:
The hydrodynamic characters,disturbance of bubble motion to bed and relationship between bubble size and distributed plate position under the initial fluidization velocity in fluidized chlorination of high-titanium slag in Yunnan was studied based on the Euler Two-fluid Model and Critical Fluidization Velocity Empirical Formula for fluidized chlorination,combining with the physical parameters of Yunnan high-titanium slag.The results show that the Grace Correlation can precisely predict the bubble behaviors in fluidized chlorination of the high-titanium slag with narrow size distribution of B-type particles,and the appearance of emulsion phase and bubbles predicted by Wen-Yu Correlation under initial fluidizing velocity is postponed.The bubbles are formed at the distributed plate positions through three stages of rise,consolidation and burst under full fluidizing velocity.The solid-vector diagram of the high titanium slag indicates that the whole bed is demarcated by the bubbles and the bubble rising process affects the fluidization of upper and lower particles which results in unevenness of the entire bed.

Study on Preparation Technology of Titanium Oxycarbid Consumable Anode by Single Sintering Process

Zhou Yuchang

2017, 38(2): 37-40. doi: 10.7513/j.issn.1004-7638.2017.02.006

Abstract(37) PDF(1)

Abstract:
Titanium oxycarbid consumable anode was prepared by single sintering process with asphalt as additive agent.Electrochemical dissolution behaviors of titanium oxycarbid consumable anode in NaCl-KCl-TiCl_x molten salt system was researched.The results show that titanium oxycarbid consumable anode with 1.3 g/cm³ 1.4 g/cm³ of density and strength meeting the requirements of the electrolytic process can be obtained under the optimal conditions. The consumable anode prepared by single sintering process can normally dissolve in the molten salt systems.

Experimental Study on Precipitation of Vanadium Using Melamine

Jiang Lin, Wang Jun, Fu Zibi

2017, 38(2): 41-45. doi: 10.7513/j.issn.1004-7638.2017.02.007

Abstract(16) PDF(1)

Abstract:
The purified alkaline vanadium solution obtained from the process of sodium roasting for vanadium slag was used as the raw material in this experiment,and the content of V and Na,and impurities content of Si and P were analyzed.A new process of vanadium precipitation under acidic condition was investigated using melamine as precipitant which substitutes for the ordinary ammonium agents such as ammonium sulfate and ammonium carbonate,etc.,and the effect of Na content in the solution on vanadium precipitation was also studied.The results show that powdery V₂O₅ satisfying the standard requirements is obtained after 3 hours of calcination at 500 ℃ with the precipitate as raw material,which is prepared at 0.3 of mole ratio of melamine to vanadium,pH = 2. 0,90 ℃ of precipitation temperature for 45 min. The precipitation rate of vanadium at the optimum conditions mentioned above is more than 98%,and the content of remaining vanadium and NH₄⁺ in the wastewater keeps at an extremely low range,simplifying the subsequent treatment process for waste water. This method is suitable for the aqueous solution where n[Na]/n[V]≤5.0 （mole ratio） and has an excellent test result.

Hot Deformation Behaviors and Processing Map of TA17 Titanium Alloy

Ren Wanbo, Li Jun, Yu Hui, Wang Ying

2017, 38(2): 46-52. doi: 10.7513/j.issn.1004-7638.2017.02.008

Abstract(29) PDF(2)

Abstract:
In order to study the hot deformation behaviors and deformation characteristics of TA17 titanium alloy,the thermal compression experiments were carried out on Gleeble-3800 thermal simulator at the deformation temperature ranging from 700 to 1 100 ℃,strain rate ranging from 0. 1 to 40 s^-1 with 60%height reduction of the specimen.The constitutive equation of TA17 titanium alloy was established based on the Arrhenius model,and the hot processing map of the alloy,which was verified by microstructure analysis for the samples,was established based on the Dynamic Materials Model （ε = 0. 6）. The results show that the predicted results by the hot processing map are in accordance with the microstructure analysis,indicating that the instable zones for TA17 processing locate in areas where the temperature is below 750 ℃ or the strain rate is higher than 10 s^-1, and the safe processing zones are outside the instable ones with 800 ℃ and 0.1 s^-1 for the processing zone possessing the best hot working performance.

Preparation of H₂TiO₃ Lithium-ion Adsorbent Using Ti-rich Material and Its Adsorption Performance Study

Tang Dahai, Zhou Jiabei, Zhou Dali, Yao Qianqian, Zhang Liyuan

2017, 38(2): 53-58. doi: 10.7513/j.issn.1004-7638.2017.02.009

Abstract(10) PDF(1)

Abstract:
β-Li₂ TiO₃ was synthesized as precursor of the lithium-ion adsorbent via solid-phase reaction using Ti-rich material as titanium source,which was prepared by purification of melt-separated titanium slag.H₂ TiO₃ lithium-ion adsorbent was finally obtained after extracting Li⁺ from the precursor Li₂ TiO₃ via acid treatment.The synthesis temperature of precursor Li₂ TiO₃ was investigated and the adsorption properties of the adsorbent were studied using adsorption kinetics model and Langmuir adsorption isotherm equation.Precursor β-Li₂ TiO₃ with good crystallization was obtained at 750 °C.In LiOH solution with 2 g/L of Li⁺ concentration, Li⁺ adsorption capacity of the adsorbent reached 28.51 mg/g.Li⁺ adsorption capacity increased with increase in alkalinity and Li⁺ concentration of the solution.The theoretical maximum adsorption capacity calculated by Langmuir equation was 45.6 mg/g for the obtained adsorbent.

Preparation and Photocatalytic Property of Nitrogen-doped Nano-TiO₂

Wang Quanzhong, Liu Hua, Liu Yali, Guo Da, Chen Yahong, Yang Zhiguang

2017, 38(2): 59-63. doi: 10.7513/j.issn.1004-7638.2017.02.010

Abstract(11) PDF(1)

Abstract:
The nitrogen-doped nano-TiO₂ （N-doped nano-TiO₂） was prepared by sol-gel method with urea as nitrogen source and tetrabutyl titanate as titanium source. The crystal structure and morphology of the samples were characterized by FT-IR,XRD,UV-Vis and SEM,respectively. The photocatalytic activity of the obtained N-doped nano-TiO₂ was investigated through degradation of the methyl orange. The results show that the N-doped nano-TiO₂ has the anatase structure and a uniform particle size distribution with excellent dispersibility,and the degradation rate to methyl orange can be reached to 97% showing a superb photocatalytic performance.

Effect of Multilayer Graphene and Fe₂O₃ Nanoparticles on Wear Behavior of TC11 Alloy

Wen Guohong, Zhou Yin, Huang Kezhi, Zhang Bo, Cao Zhen, Wang Shuqi

2017, 38(2): 64-69. doi: 10.7513/j.issn.1004-7638.2017.02.011

Abstract(15) PDF(1)

Abstract:
The effect of multilayer graphene and Fe₂O₃ nanoparticles on the wear behavior of TC11 alloy was investigated by adding the mechanical mixtures of multilayer graphene and Fe₂O₃ nanoparticles to the friction interface of the alloy.As a comparison,the wear tests with no additive and adding pure multilayer graphene or Fe₂O₃ nanoparticles were performed. The phases,morphologies and compositions of the worn surfaces were systematically analyzed by XRD,SEM and EDS. The formation process of the friction-layer and the function mechanism of the nano-materials were explored.The results show that the wear resistance of TC11 alloy was not improved when single multilayer graphene or Fe₂O₃ was selected as additives,which was ascribed to the unstable existence of the formed friction-layers.However,with the additive of mechanical mixtures of multilayer graphene and Fe₂O₃ nanoparticles,a double friction-layer simultaneously with excellent lubricant and load-carrying capacity was formed on the worn surface,which can effectively avoid metal-metal contact and protect the substrate,finally reducing the wear loss for TC11 alloy.

Analysis of the Aluminum Ion Deposition in the Inorganic Coating Process for Titanium Dioxide

Du Jianqiao, Zhong Benhe

2017, 38(2): 70-74. doi: 10.7513/j.issn.1004-7638.2017.02.012

Abstract(13) PDF(2)

Abstract:
In order to reveal the behaviors of aluminum ion deposition in inorganic coating process for titanium white,the spectrophotometric method was used to confirm the pH range of deposition for different aluminum salts,and the number of particles and particle size were monitored by the online particle detector in the precipitation process of aluminum ion.Furthermore,the precipitates obtained at different acidity conditions were analyzed by FT-IR,SEM and XRD to determine their characteristics. This research can provide a reference for inorganic coating of titanium dioxide.

Effects of Heat Treatment Systems on Properties of Titanium Alloy Tube by Hydraulic Bulging

Wang Junzhou

2017, 38(2): 75-80. doi: 10.7513/j.issn.1004-7638.2017.02.013

Abstract(10) PDF(1)

Abstract:
Ti-Al-V-In new-typed titanium alloy thin-walled tube samples by hydraulic bulging were heat treated with different heat treatment systems,and the mechanical properties and corrosion resistance of the tubes were tested and analyzed. The results show that compared with common annealing,both isothermal annealing and ultrasonic vibration isothermal annealing could improve the mechanical properties and corrosion resistance of the tube,while the improvement effect of ultrasonic vibration isothermal annealing is more significant with the tensile strength,yield strength and elongation respectively increased by 22%,32% and 18%,the corrosion potential shifted positively by 146 mV and the corrosion current density decreased by 71%.The optimized heat treatment system is ultrasonic vibration isothermal annealing,with the high temperature,low temperature and ultrasonic vibration frequency optimized at 820 ℃,540 ℃ and 35 Hz,respectively.

Influence of Alkalinity on the Properties of Blast Furnace Slag Conditioning Agent

Sun Chaijiao, Zhang Yuzhu, Li Jie, Li Junguo, Hong Lukuo

2017, 38(2): 81-86. doi: 10.7513/j.issn.1004-7638.2017.02.014

Abstract(10) PDF(1)

Abstract:
According to the adjustment of molten blast furnace slag for preparation of mineral wool,the influence of iron tailings,basicity contents on the viscosity and melting temperature of the slag system has been investigated.Based on the basic composition of slag cotton,a certain amount of modifier was added into the molten blast furnace slag for adjusting chemical composition and then heated up and mixed. The result shows that when the blast furnace slag is adjusted with chemical reagent,the viscosity of the slag can transfer to the short-slag characteristics and the melting temperature increases with the increasing of basicity,which do not benefit for fluidity increasing of the slag.Basicity has not significant influence on the surface tension of blast furnace slag.The right basicity for preparation of slag cotton is 1.0.

Effect of Recycling Waste Water on Producing Clean Vanadium Oxide Using Dilute Sulfuric Acid Leaching Method

Wang Jin

2017, 38(2): 87-92. doi: 10.7513/j.issn.1004-7638.2017.02.015

Abstract(9) PDF(1)

Abstract:
To solve problems that recycling wastewater pH、SS、Mn²⁺、NH₄⁺ concentration change greatly to cause vanadium precipitation and low yield of vanadium during calcified roasting clinker leaching with sulfuric acid and ammonium salt precipitation of vanadium process in clean production,the effect of recycling wastewater pH、SS、Mn²⁺、NH₄⁺ concentration on immersion ratio of vanadium was studied using the method of sulfuric acid leaching by taking wastewater and roasting clinker as raw material. Meanwhile,compare the wastewater with deionized water to leaching-filtering-washing effect were studied. The results show that with the increase of wastewater pH,acid leaching residue of vanadium content decreases,vanadium leaching rate increases and with increasing recycling wastewater SS、Mn²⁺、NH₄⁺ concentration,acid leaching residue of vanadium content increased,vanadium leaching rate decreased sharply. Recycling wastewater and deionized water to leaching-filtering-washing effect is similar to that of acid leaching residue of vanadium content can be reduced to 1.2%,vanadium leaching rate can be achieved 85% when recycling wastewater of pH = 6.5~7.5,Mn²⁺≤3 g/L,SS≤30 g/L,NH₄⁺≤25 g/L. The experimental results provide the technical control requirements and data reference for the wastewater treatment and recycling of the industrial waste water in the process of producing clean vanadium from the calcified roasting clinker sulfuric acid leaching and ammonium salt precipitation vanadium.

Study on Preparation of Mullite from Low Grade Coal Gangue

Yang Qiang, Song Shaolei, Bu Naijing, Zhen Qiang

2017, 38(2): 93-97. doi: 10.7513/j.issn.1004-7638.2017.02.016

Abstract(19) PDF(1)

Abstract:
Using the coal gangue after acid leaching and alumina oxide as raw material,the effect of synthetic on mullite phase was researched under different experimental conditions.When the heating temperature is 1 200 ℃ a rod like mullite crystal appears,.With the temperature exceeding 1 500 ℃,significant amount of mullite is obtained and its amount further increases while temperature reaching up to 1 600 ℃.By changing the holding time under highest heating temperature,the degree of mullitization firstly increases and then decreases.With the coal gangue dosage increasing,corundum phase peak enhances,which indicates that the increase of coal gangue dosage has negative role in synthesizing mullite. By changing the rate of silicon and aluminum from 3 ∶ 2 to 1 ∶ 1,the degree of mullitization gradually enhances.When the ratio of silicon and aluminum is 1 ∶ 1,corundum phase peak disappears,which indicates that low-grade coal gangue with lower alumina-silica ratio is beneficial for the synthesis of mullite.

Research on Temperature Field of energy-saving ladle with Adding lid by Thermal Coupling Numerical Simulation

Luo Jiazhi, Huang Chengyong, Qiu Long, Li Yingjie, Zhao Guoguang, Fan Bailin, Lian Kaifa, Xin Wenping

2017, 38(2): 98-103. doi: 10.7513/j.issn.1004-7638.2017.02.017

Abstract(11) PDF(1)

Abstract:
The temperature field of a 100 t ladle during static process was calculated by using Fluent software,and he temperature drop curves of with and without adding lid were obtained.Influence of lid on the temperature field of ladle was analyzed.The static time was set at 10 min and 60 min respectively,and the influence of static time on the temperature field of ladle had been analyzed.The results show that temperature drop of ladle in the first 10 min period is relatively significant,and with increasing static time,ladle temperature decreases slowly. Ladle adding lid technology can achieved remarkably energy saving effect.Average temperature loss of the converter tapping steel was reduced by 15 ℃,and cost reduction could be reduced by at least RMB 0.8 per ton steel.

Comparative Research on Micro-mechanical Properties of Vanadium-titanium Sinter and Ordinary Sinter

Deng Ming, Wang Wei, Xu Runsheng, Lin Wenkang, Zhang Zhiqiang, Huang Yun

2017, 38(2): 104-111. doi: 10.7513/j.issn.1004-7638.2017.02.018

Abstract(15) PDF(1)

Abstract:
In this paper Vivtorinox indentation had been used to detect micro-hardness of the common minerals in vanadium-titanium sinter and ordinary sinter,and the micro hardness of different minerals had been compared as well as indentation crack initiation and propagation had been analyzed. Micro-hardness measurement shows that the common minerals in two kinds of sinter with their hardness at descent order are: perovskite,titanium hematite,calcium ferrite,mixed corrosion structure,titanium magnetite,silicate;hematite,mixed corrosion structure,calcium ferrite,magnetite,silicate.Above all,the micro hardness of vanadium-titanium sinter is higher than that of ordinary sinter,but some mineral in vanadium-titanium sinter appears many indentation cracks and longer propagation.The fracture toughness of perovskite and titanium hematite is lower,and readily for cracking. For sinter ore,the micro hardness can be increased and the quality of sintered ore can been improved by reducing the plate hematite and developing the calcium ferrite and the mixed corrosion structure.

Study on Texture of Sinter with Different Basicity

Liu Lina, Han Xiuli, Liu Lei

2017, 38(2): 112-115. doi: 10.7513/j.issn.1004-7638.2017.02.019

Abstract(16) PDF(3)

Abstract:
The texture of sinter with different basicity had been investigated by means of polarization microscope.The result shows that the metal phase of the sinter with hematite ore and magnetite ore is magnetite and hematite,but the hydrotitanite appears in the sinter with vanadium titano-magnetite ore,the binder phase of the sinter with different sintering raw material is calcium ferrite,dicalcium silicate and glassy.With the basicity of sinter increasing,the content of the metal phase is increased and the binder phase is reduced,the texture is uniform gradually with different sinter,the texture of sinter with hematite ore and magnetite ore is porphyric to erosion interleaving structure,and the sinter with vanadium titano-magnetite ore is magnetite and metaperovskite distribution together to resorption texture.

Experimental Research on Optimization of Sintering Mixture with Low-grade Complex Ore from Xinjiang

Ding Yuchuan, Zhu Zizong, Zhou Zhiqiang, Xiong Hao, Yang Zhenxing

2017, 38(2): 116-120. doi: 10.7513/j.issn.1004-7638.2017.02.020

Abstract(7) PDF(1)

Abstract:
In order to utilize the lean ore resources rationally and optimize mixture,experimental schemes of sinter mixture were designed and carried out under different basicity,different carbon content as well as different fuel particle size by the sintering cup.The results show that the sinter strength decreased by 5%,low temperature reduction disintegration index （RDI） is the lowest and the natural degradation index of the sinter was higher when sinter basicity is between 1.65 and 1.75.The sinter strength increases when sinter basicity varies from 1.75 to 2.0.Meanwhile,the sinter strength and RDI_+3.15 has been improved with the carbon content increasing.The sinter strength and RDI_+3.15 also went bad with the fuel particle size getting smaller.

Carburization Experiment of Vanadium-containing Hot Metal and Choicee of Carburant

Ma Deng, Wu Wei, Liu Zhibin, Zhao Bin, Wang Jie, Liu Xiaoliang

2017, 38(2): 121-127. doi: 10.7513/j.issn.1004-7638.2017.02.021

Abstract(10) PDF(2)

Abstract:
Firstly,thermodynamic analysis of carbon dissolution had been made.It proved that carburization process was provided with good thermodynamic condition,however,carburization process was restrained by oxidation of carbon.Based on these research results,carburization experiment of laboratory level had been conducted.Five kind of carburant are employed in the experiments at temperature of 1 500 ℃.The rank of carburization efficiency for five carburizers is obtained as follows: low nitrogen carburant,graphite,anthracite,carbon granule and coke.It is concluded that the difference of carburization amount is mainly related with contents of both sulfur and ash in the carburizers.Carburization amount decreases with the increase of sulfur content or ash content in the carburizer.The magnitude of rate constant of the carburization reaction is calculated to be 10^-4s^-1.Anthracite is the most suitable carburizer among the five carbonaceous materials.Addition of 13.2 kg anthracite brings 0.5% increase of carbon content in practical production.

Development of 160 MPa Low Yield Point Steel Plate Used For Earthquake Resistant

Chen Zhenye, Sun Li, Liu Hongqiang, Sun Xiaoran, Li Shuangjiang

2017, 38(2): 128-131,135. doi: 10.7513/j.issn.1004-7638.2017.02.022

Abstract(14) PDF(1)

Abstract:
The 160 MPa low-yield strength steel plate with 40 mm and 80 mm thicknesses for building aseismicity was developed through reasonable composition design and rolling technology.The LY160 steel could meet the requirements of GB/T28905—2012.The microstructure of the LY160 steel plate （40 mm） consists of ferrite andvery small amount of bainite.The grain sizes range from ASTM No.7 to 7.5.Yield strength is from 157 MPa to 168 MPa and tensile strength is from 291 MPa to 304 MPa.The impact energyat 0 ℃ ranges between 289 J and 311 J.The microstructure of the LY160 steel plate with 80 mm in thicknessis 100% ferrite.The grain sizes ranges from ASTM No.5 to 5.5.In addition,the yield strength is from 150 MPto 163 MPa,The tensile strength is from 280 MPa to 285 MPa.The impact energy at 0 ℃ ranges between 73 J and 92 J.The new developed LY 160 steel plate combines high low-cycle fatigue property and excellent weldability.

Analysis of Inclusions in the Surface Layer of IF Steel Slab

Liu Zengxun, Hu Shuo, Li Meng, Xiao Pengcheng

2017, 38(2): 132-135. doi: 10.7513/j.issn.1004-7638.2017.02.023

Abstract(7) PDF(1)

Abstract:
For the variation of inclusions in the surface layer of IF slab,the size,quantity,distribution,composition and source of inclusions were investigated by means of total oxygen and nitrogen content analysis,optical microscopy,scanning electronic microscopy （SEM） and energy dispersive X-ray spectroscopy （EDS）.The results show that the amount of inclusions at the position of 3~4 mm from the inner arc surface is the highest,reaching 9.2 per mm² at 3 mm inner the surface and 8.8 per mm² at 4 mm inner the surface,while the quantity of inclusions ranges from 5.1 to 6.8 per mm² in other positions.The distribution of inclusion in the width direction is random.The majority of surface layer inclusions are Al₂O₃-TiO_x and Al₂O₃ whose size are mainly less than 20 μm,which accounts for 84% of the total amount of inclusions.

Study on Non-metallic Inclusions of Sour Service Pipeline Steel

Deng Xuyan, Hu Chujiang, Duan Baomei, Li Lingxia

2017, 38(2): 136-142. doi: 10.7513/j.issn.1004-7638.2017.02.024

Abstract(21) PDF(1)

Abstract:
The number,size,chemical composition and morphology of inclusions in the sour service pipeline steel samples taken from individual steelmaking process stages and billet were analyzed using SEM and bulk sample electrolysis. The results indicate the area fraction of micro inclusions in the liquid steel decreases by 34.7% in the LF process; the area fraction of micro inclusions in the liquid steel of tundish increases by 6.1% compared with VD end.The dominant inclusion type is Al₂O₃ at LF start; The composite inclusions containing mainly CaO、MgO、Al₂O₃ form due to the steel/slag reaction in the LF and VD process.The amount-of-substance ratio of CaO to Al₂O₃ in the inclusions is close to 12 ∶ 7 after calcium treatment,desulphurization reaction between inclusions and liquid steel occurs and forms composite inclusions containing CaS.There are much more micro and macro inclusions in the billet at casting start stage compared with stable casting stage; T[O] content in the billet is less than 15×10^-6,and the macro inclusion content in the billet is less than 0.2 mg/kg in the stable casting stage; the macro inclusions in the billet are mainly from filler sand of ladle,mold powder.

Analysis and Research on The Segregation of A-type Inclusion in Rail Steel

Li Hongguang, Chen Tianming, Chen Liang, Guo Dianrong

2017, 38(2): 143-149. doi: 10.7513/j.issn.1004-7638.2017.02.025

Abstract(20) PDF(1)

Abstract:
Through measuring type-A non-metallic inclusion of sample taken from different depths and location in the steel rail,we found out that that the result is contingent.In this paper taking U75V steel rail as researching object,the separation of MnS in rail steel had been predicted by Factsage software and thermodynamic calculation,,and verified by combining the solidification characteristic of molten steel in the casting process with results of produce statistics and actual testing.It is found out that MnS separates from the nearly full solidified liquid steel,and mainly caused by segregation of S and Mn while molten steel solidifying.Based on the control of decreasing the content of [O]%、[N]%,decreasing the content of [S]% and try to make modification for MnS with Ca or Ti and improve the quality of billets,can help to prevent MnS segregation and deformation while subjecting to rolling.

Small Range Control of Pearlite Microstructure and Properties of 65Mn Hot Rolled Narrow Strip

Wang Yuehua, Song Jinying, Wei Yingli, Zheng Xiaoping, Tian Yaqiang, Liu Zhixing, Sun Xueyu

2017, 38(2): 150-155. doi: 10.7513/j.issn.1004-7638.2017.02.026

Abstract(12) PDF(1)

Abstract:
The pearlite microstructure and mechanical properties of 65 Mn hot rolled narrow strip was tested by OM、SEM、tensile testing machine and Rockwell hardness tester under different finishing temperature,cooling rate after finish rolling and cooling rate after coiling for formulation of small range quality control process parameters.The results show that with the increase of finishing temperature,the reduction of the cooling rate after finish rolling and increase of the cooling rate after coiling,the pearlite colony and pearlite interlaminar spacing increase,lamellar thicken and tensile strength and hardness gradually decrease.When finishing temperature is greater than 960 ℃,the cooling rate after finish rolling is less than 5.58 ℃/s and the cooling rate after coiling is less than 0.1 ℃/s,the resulting tensile strength is less than 900 MPa.

Genesis and Control of Surface Sliver Defects of IF Steel Cold Rolled Sheets

Deng Jianjun, Wang Rui, Hao Yang, Chen Xiao

2017, 38(2): 156-160. doi: 10.7513/j.issn.1004-7638.2017.02.027

Abstract(16) PDF(1)

Abstract:
Sliver defect is one of the most common defects in IF steel cold rolled sheet.In this paper,the genesis of cold rolled IF steel sheet sliver defects in Handan Iron Steel Group have been studied,and some methods of reducing sliver defects have been proposed. SEM-EDS result indicates that there are a large amount of small-sized Al₂O₃ particles in the sliver defects.According to SLIME results of slabs at different casting stages,there are high amount of large-sized Al₂O₃ inclusions in ladle changing and SEN changing slabs,which originate from the drop off of clogs in entry nozzle. Therefore,it can be concluded that the clogs in entry nozzle drop off into mould and develops as a large-size Al₂O₃ inclusion in the slabs,which causes surface sliver defects during cold rolling process.

Reasons and Improvement of Wrinkling on Strip Surface

Li Meng, Chai Siyu, Xiao Pengcheng, Zhu Liguang, Liu Zengxun

2017, 38(2): 161-166. doi: 10.7513/j.issn.1004-7638.2017.02.028

Abstract(12) PDF(1)

Abstract:
In order to identify the reason forwrinkling defects at Q195 cold rolled galvanized steel strip,the large size and micro-size inclusions of samples taken from the various process steps of steelmaking had been characterized by utilizing large sample electrolysis,metallographic microscope,scanning electron microscope （SEM）. The results showed that the cold rolling defects are mainly due to the volume of ladle slag and ladle refractories caused by spalling was confirmed. By improving the process parameters and modify the ladle liner,wrinkling defects of cold rolled products were eliminated.

2017, 38(2): 167-168.

Abstract(16) PDF(1)

Abstract:

2017 Vol. 38, No. 2