钢铁钒钛

Experimental Research on Vanadium Extraction by Calcified Roasting and Acid Leaching

Fu Zibi

2014, 35(1): 1-6. doi: 10.7513/j.issn.1004-7638.2014.01.001

Abstract(146) PDF(14)

Abstract:
To solve problems arising during calcified roasting and acid leaching processes in vanadium extraction industrial test,the influence of key process parameters on extraction of vanadium was studied by taking vanadium slag from Pangang as raw materials.The research focused on the influence of Cao/V₂O₅ ratio,roasted materials' particle sizes,metallic iron content in roasted materials and final pH value of leaching slurry on vanadium leaching rate and the influence of oxidizability of roasting atmosphere on the optimum roasting temperature,and the influence of P concentration of leaching liquid on precipitation of vanadium.The results show that a higher vanadium leaching rate can be obtained with CaO/V₂O₅ ratio of 0.54~0.70,the roasted materials' particle sizes of -0.096 mm,metallic iron content in roasted materials equal to or less than 2% and the final pH value of leaching slurry not higher than 4.1.With 15% of oxygen in inlet gas(the corresponding oxygen content in exhaust gas is about 12.5%),the optimum roasting temperature is 850~870℃,and the corresponding vanadium leaching rate is 88.29%~88.66%.When the acid leaching liquid contains 32 g/L of TV,P concentration should be controlled below 0.06 g/L.

Experiments on Reduction of Molten Titanium Slag by Pulverized Coal Injection

Zhang Feng, Liu Kaiqi, Wang Shouzeng, Qi Zhaodong, Gu Jing

2014, 35(1): 7-10. doi: 10.7513/j.issn.1004-7638.2014.01.002

Abstract(39) PDF(0)

Abstract:
The grade of titanium slag may not meet the requirement in some short processes of titanium slag smelting.In order to solve the problem,a simulating experimental device of electric furnace was built under laboratory conditions to melt titanium slag,and pulverized coal was injected to the molten slag to improve its grade.The effect of coal injection amount and reaction time on titanium slag's grade was also investigated.Results show that the grade of titanium slag rises with the increase of the coal injection amount,and as the coal is injected,the grade of titanium slag rises before it falls.To be more specific, the grade of titanium slag rises from 70% to 82% after 7 kg of pulverized coal has been injected into 50 kg of molten slag at 1 600℃ for 20 minutes and reacted for another 20 minutes.This conclusion will provide a new way to improve the grade of titanium slag which is smelted by short processes.

Experimental Study on Direct Leaching of Black Shale- hosted Vanadium-bearing Clay Mineral Concentrates by H₂SO₄

Ji Chengqing, Shen Mingwei, Zhu Changluo, Hui Bo, Yang Changyan, Cai Wang

2014, 35(1): 11-15. doi: 10.7513/j.issn.1004-7638.2014.01.003

Abstract(49) PDF(0)

Abstract:
Vanadium-bearing clay mineral is one of typical vanadium resources which are difficult to utilize.The feasibility of direct leaching of black shale-hosted vanadium-bearing clay mineral concentrates by H₂SO₄-CaF₂-NaClO₃ system was studied.Furthermore,the influencing factors of leaching were investigated.The results show that H-SO₄-F acid solution system with high concentration can effectively destroy the mineral structures of mica,clay minerals and limonite.Vanadium leaching rate reaches 90.0% or above with 85% of concentrates' sizes smaller than -74 μm,reaction temperature at 80℃,liquid to solid ratio(volume/mass,mL/g) of 2.5 to 4.0:1、H₂SO₄ (98%) addition amount higher than 54%, stirring speed of 400 r/min,NaClO₃ addition amount of 1.25%,CaF₂ addition amount of 12%,and leaching time of 11 h.under the conditions,vanadium leaching rate is higher than that of the traditional roasting method.sulfuric acid and fluoride ions can be effectively recovered by diffusion dialyzer.

Experimental Study on Recovery of Vanadium from Low-grade Vanadium Slag Containing High Calcium Content

Li Kunlin, Ren Shaolong, Cheng Feng

2014, 35(1): 16-20. doi: 10.7513/j.issn.1004-7638.2014.01.004

Abstract(70) PDF(5)

Abstract:
A laboratory test was carried out to prepare V₂O₅ from low-grade vanadium slag containing high calcium content by salt roasting-water leaching processes.By using the methods of single roasting and mixed roasting with ordinary vanadium slag,the technologies and relevant parameters were obtained for V₂O₅ preparation from the above-mentioned vanadium slag.The results show that the method of mixed roasting with ordinary vanadium slag is better than single roasting.The best results can be achieved in mixed roasting with the soaking time of 2.5 hours,the mass ratio of soda to salt of 100:15,the mass ratio of ordinary vanadium slag to low-grade vanadium slag of high calcium to tailings of 50:30:20,and the temperature of 800℃.Under the conditions,the leaching ratio reaches 85% or above.The V₂O₅ finished products prepared from leaching solution after dephosphorization,vanadium precipitation and roasting meet the standards of YB/T 5304 -2011.

Effect of Formation Rate of Silicon Gel on Compact Silicon Coating of Titanium Pigment

Liu Shu, Zhou Dali, Kuang Linna, Lü Bo, Du Jianqiao, Lei Xinyi

2014, 35(1): 21-26,31. doi: 10.7513/j.issn.1004-7638.2014.01.005

Abstract(57) PDF(2)

Abstract:
A study on mechanism of compact silicon coating of titanium pigment was carried out.Through thermodynamic analysis of silicic acid aqueous solution system,the advantage existing zones of H₅SiO₄⁺, H₄SiO₄,H₃SiO₄^- and H₂SiO₄^2- produced by hydrolysis of silica gel were drawn.With the addition of silicate concentration,the advantage existences tend to move to higher pH.It can be concluded from the experiment of gel formation and thermodynamic analysis that the gel formation rate is determined by the concentration of both H₄SiO₄ and other silicate ions.When the distrabution coefficient of H₄SiO₄ and H₃SiO₄^- are equal,the product of their concentration is the largest at certain total concentration of silicate ions.With the increase of silicate ions' total concentration,the gel formation rate speeds up.If the rate is out of control,flocculent silicate would form,which affects the coating compactness.With the temperature of 80℃ and silicate ion' concentration of 0.2 mol/L,0.3 mol/L and 0.4 mol/L,the pH value of the system should be greater than 9,9.5 and 10 respectively.

Research on the Influence of Dispersants on Coating of TiO₂

Cheng Xiaozhe

2014, 35(1): 27-31. doi: 10.7513/j.issn.1004-7638.2014.01.006

Abstract(92) PDF(10)

Abstract:
With a pH value of 9.0 to 10.0,Zeta potential of rutile titanium dioxide slurry reaches the maximum value,and the titanium dioxide has the best dispersion property in water.In this paper,the changes of viscosity in the coating process were studied as sodium silicate,sodium hexametaphosphate, sodium pyrophosphate,or ammonium dihydrogen were used as dispersants respectively.The results show that the slurry has lowest viscosity by taking sodium silicate or sodium hexametaphosphate as dispersant, and when sodium silicate is added at an amount of 0.15% all at once,the slurry's viscosity is the lowest in coating process.Moreover,BET and SEM-EDS analyses on surface compositions of coated titanium dioxide indicate that with lower slurry viscosity during the coating process,coating agents will deposit more evenly and compactly on the surface of TiO₂.

Preparation of La³⁺-doped TiO₂ and Its Photocatalytic Performance

Li Minjiao, Zhang Shulin, Lu Yan, Yu Hong, Zhu Wei

2014, 35(1): 32-35. doi: 10.7513/j.issn.1004-7638.2014.01.007

Abstract(52) PDF(2)

Abstract:
La³⁺-doped TiO₂ with different molar ratios of La/Ti(1/100,2/100,3/100,4/100 and 5/100) were prepared by a facile Sol-Gel method.The photocatalysts prepared were characterized by Brunauer-Emmet-Teller(BET) method,X-ray diffraction(XRD),UV-Vis diffuse reflectance spectra and surface photovoltage spectra(SPS).The results showed that TiO₂ doped with 4%(the molar ratio of La/Ti) of La³⁺ had the highest photoinduced charge separation rate.The decolorizing performances of TiO₂ and La³⁺-doped TiO₂ was evaluated respectively by using aqueous methyl orange solution as simulative azo dye,and it could be concluded that the TiO₂ doped with 4% of La³⁺ has the best photocatalytic performance.

On the Work-hardening Mechanism of TWIP Steels Strengthened by Nanometre-sized Vanadium Carbides

Liang Z Y, Huang M X, Yen H W, Scott C P

2014, 35(1): 36-40. doi: 10.7513/j.issn.1004-7638.2014.01.008

Abstract(85) PDF(1)

Abstract:
Experiments reveal that while dispersed nanometer-sized vanadium carbides can greatly increase the yield strength of twinning induced plasticity(TWIP) steels,they may cause some reduction of the overall work-hardening rate.A modified physically based model is adopted in the present work to capture the effect of nanometer-sized vanadium carbides on the work-hardening rate of a laboratory FeMnC austenitic TWIP grade.It is found that the introduction of the dispersed nanometer-sized carbides leads to a faster dislocation accumulation rate but reduces the rate of twin formation with strain during plastic deformation.Compared to a reference alloy without precipitates the work-hardening rate is higher at small strains but decreases faster than the reference thus presenting a lower work-hardening rate at high strains.

Thermodynamic Analysis on Precipitation Behavior of Titanium-containing Precipitated Phases of Titanium-alloyed High Boron Steel

Yang Hao, Liu Ying, Li Jun, Zhang Hui, Ma Yu

2014, 35(1): 41-47. doi: 10.7513/j.issn.1004-7638.2014.01.009

Abstract(97) PDF(0)

Abstract:
The precipitation behavior of the titanium-containing precipitated phases of titanium-alloyed high boron steel in liquid phase and during solidification has been studied by thermodynamic calculation and experiments.Solidification microstructures of the high boron steel were researched by means of optical microscope(OM),scanning electron microscope(SEM),X-ray diffractometer(XRD).The results show that the solidification microstructures of cast alloy without alloying with Ti consist of boride,ferrite, and pearlite,and boride successively distributes along grain boundary in reticular form,while the microstructures of titanium-alloyed cast alloy consist of second-phase TiC,boride and matrix.Thermodynamic calculation results show that the titanium-containing precipitated phases cannot precipitate in the liquid phase; TiC can precipitate at 1691K when the solidification volume fraction reaches 29% during its solidification,and the precipitation sequence of the precipitated phases is TiC > TiB₂> TiB.

Effect of Titanium Content on Microstructures and Mechanical Properties of Fe-C-B-Ti Alloy

Zhang Hui, Liu Ying, Li Jun, Yang Hao, Ma Yu

2014, 35(1): 48-53. doi: 10.7513/j.issn.1004-7638.2014.01.010

Abstract(56) PDF(0)

Abstract:
The microstructure,hardness and impact toughness of as-cast or quenched Fe-C-B-Ti alloy containing 0.67%~1.82% of Ti were studied.The results show that the microstructures of the as-cast Fe-C-B-Ti alloys containing 0.67% of Ti consist of martensite,pearlite and reticular eutectic boride with high hardness and impact toughness.With the increase of titanium content,the martensite of the as-cast Fe-C-B-Ti alloy gradually disappears,and ferrite appears,which results in gradual decrease of hardness and impact toughness.After heat treatment,the reticular eutectic borides of the alloys are broken,and grow coarser noticeably with the increase of temperature.As the quenching temperature arises,the hardness and impact toughness of the Fe-C-B-Ti alloy increase,and achieve maximum value at 1 050℃ while they decrease over 1 050℃.

Strengthening Mechanism of the Ti-microalloyed Container Plate Q345R

Zhou Jialin, Lai Chunming, Pan Chenggang, Pi Xinyu, Hu Tangguo

2014, 35(1): 54-58. doi: 10.7513/j.issn.1004-7638.2014.01.011

Abstract(31) PDF(0)

Abstract:
An experiment research on the Ti-microalloyed container plate Q345R was conducted to test its mechanical properties,microstructures and precipitates.The results show that the tested steel has good strength,ductility,and low-temperature impact toughness.The misconstrues of the steel are composed of ferrite and pearlite with the grain size of grade 12 or so.The precipitate is mainly TiN with sizes of 50~100 nm,and the precipitation begins at 1 343℃ which is below the solidus temperature(TS).Calculations show that TiC can not be formed due to low titanium content.Refined crystalline strengthening and solid solution strengthening contribute most to the strength properties.

Production of High-strength Aseismatic Rebar HRB500E Multi-microalloyed with VN or VN + Mo

Wang Hongli, Li Yizhang, Zhao Rulong, Fan Yi, Li Ronghua

2014, 35(1): 59-63. doi: 10.7513/j.issn.1004-7638.2014.01.012

Abstract(86) PDF(5)

Abstract:
In order to increase the strength and yield strength-to-tensile strength ratio of the aseismatic rebar,high-strength aseismatic rebar HRB500E was produced by employing different microalloying way and cooling process after rolling according to practical production conditions of bar and wire rod units in Pangang Group Chengdu Steel & Vanadium Co.,Ltd.When Ø 6~12 mm HRB500E was produced by high speed wire mill,the steel was micro-alloyed by VN and Stelmor wind cooling process was adopted.After 0.08%~0.11% of V was added to the steel,V to N ratio was close to 4:1.When Ø 14~40 mm HRB500E was produced by bar mill,the steel was micro-alloyed by VN + Mo,and natural cooling was adopted.0.06%~0.12% V and 0.03%~0.05% Mo were added to the steel,and V to N ratio was close to 4:1 after the addtion.The results show that the rebar HRB500E so produced is of high strength and good anti-seismic properties,and satisfies the national standards and client requirements.

Treatment of Reduced Wastewater after Vanadium Precipitation with Lean Slag from Ferrovanadium Smelting

Zhuang Lijun, Wang Liang, Zhao Hua, Teng Xiaohui, Ma Jinhong

2014, 35(1): 64-68. doi: 10.7513/j.issn.1004-7638.2014.01.013

Abstract(61) PDF(0)

Abstract:
In order to recycle lean slag from ferrovanadium(FeV50) smelting and treat wastewater from vanadium precipitation,lean slag with particle sizes smaller than 5 mm instead of lime powder was used after weathering and screening to neutralize the reduced wastewater with pH value of 7.0~8.5.The results indicate that 1 kg of chromium consumes 9.2 kg of lean slag ash,1.4 times of the amount of lime powder consumed.The total chromium,total vanadium,and suspended solids in the treated wastewater are less than 1.5 mg/L,1 mg/L,and 70 mg/L respectively,and its pH value is from 6 to 9,which means the treated wastewater satisfies the standard of GB26452 -2011.In a plant with an annual output of 2 000 tons of FeV50,more than 3 000 tons of waste slag generating in FeV50 smelting can be reduced each year.

Simulation Study on the Dry Centrifugal Granulation Process of Blast Furnace Slag

Chang Qingming, Cheng Yongkai, Li Xianwang, Ni Hongwei, Zhu Wenyuan, Zhang Hua, Xiong Jingchao

2014, 35(1): 69-73,78. doi: 10.7513/j.issn.1004-7638.2014.01.014

Abstract(111) PDF(11)

Abstract:
In this study,a physical and mathematical model was established to simulate the dry centrifugal granulation (DCG) process of blast furnace slag,and the process was verified by small scale experiments.The influences of various factors,including molten slag temperature(or viscosity),surface tension and rotary speed of the flat plate-type disc,on DCG process were analyzed and optimum parameters were obtained.The results show that the granulation can be greatly improved by increasing the rotary speed.In addition,by boosting the temperature(or reducing the viscosity) or decreasing surface tension of the molten slag,the granulation effects can also be promoted.

Influence of CaF₂ and MgO Addition on the Melting and Dripping Property of Blast Furnace’s Vanadium and Titanium-bearing Burden

Cui Shiqiang, Lü Qing

2014, 35(1): 74-78. doi: 10.7513/j.issn.1004-7638.2014.01.015

Abstract(52) PDF(1)

Abstract:
In order to tackle problems found in blast furnace (BF) smelting of vanadium-bearing titaniferous magnetite,experiments were carried out.Operation conditions of the BF cohesive zone were simulated in a high-temperature MoSi₂ furnace to study the influence of the addition of CaF₂ and MgO to vanadium and titanium-bearing BF burden on burden permeability,thickness of the cohesive zone,the temperature for sudden increase of pressure differential and the cohesive and molten zones etc.The results show that the addition of CaF₂ has no noticeable influence on the initial softening temperature,but narrows the softening temperature range,which means the formation of first slag zone is too earlier.As a result,the thickness of the cohesive zone,the maximum pressure differential and the general characteristic values are elevated.The addition of MgO raises the initial softening temperature,and narrows the softening temperature range as well,which indicates it addition lowers the cohesive zone,and makes it thinner.

Study on the Formation of Ti（C,N） in Low TiO₂ Content Blast Furnace Slag

Zhao Yongbin, Zhang Jianliang, Ning Xiaojun, Wei Mengfang, Mao Rui

2014, 35(1): 79-84. doi: 10.7513/j.issn.1004-7638.2014.01.016

Abstract(88) PDF(3)

Abstract:
During smelting of iron ore containing low TiO₂ content in blast furnace(BF),Ti(C,N) easily forms,which has a great influence on the performance of the slag and hot metal.Therefore,the study on its formation is of great significance for BF smelting.In this paper,the formation of Ti(C,N) in low TiO₂ content slag and its influencing factors are studied with the software FactSage,and the relationship between temperatures and[Ti] in hot metal is verified under laboratory conditions.The results show that in BF smelting of low TiO₂ content mineral,Ti(C,N) comes into being at 1 666 K,and reaches its maximum value at 1 783 K.The temperature,ratio of slag to hot metal,and TiO₂ content in the slag have greatest impact on the formation of Ti(C,N),while the content of Al₂O₃ and MgO,and dual basicity of slag contribute much less to its formation.The titanium content in hot metal is mainly affected by the temperature and Ti(C,N) reaction equilibrium,and has no obvious relationship with TiO₂ content in the slag.

Study on Mineralogical Constituents of Slag Film of Casting Powder for Continuous Casting of Plates

Liu Lina, Han Xiuli, Liu Lei, Li Zhimin, Feng Runming, Xuan Zongyu

2014, 35(1): 85-89. doi: 10.7513/j.issn.1004-7638.2014.01.017

Abstract(25) PDF(0)

Abstract:
The mineral compositions,crystallization rates,thicknesses,layered structures of slag film of casting powder for continuous casting of Q235B steel plates were analyzed by optical microscope and Xray diffractometer.The result shows that the mineral compositions of slag film consist of akermanite,cuspidine,wollastonite and glass phase.When longitudinal cracks are found on strand surface during casting,the crystalline phases of the slag film are mainly melilite and cuspidine with a crystallization rate of 50%~55%,and the film exists in a glassy layer-crystallizing layer-glassy layer structure.When sticking-type breakouts are found on strand,the slag film is dominated by crystallizing layer consisting of cuspidine and wollastonite.The crystalline phases of slag film under normal circumstances consists of melilite with crystallization rate of 90%.In order to avoid longitudinal cracks on medium carbon steel's strand surface and sticking-type breakout of strand,it it suggested that the crystallization rate be improved and the content of wollastonite be reduced.

Optimization of Six-strand Tundish’s Flow Control Devices and Analysis on Erosion of the Tundish’s Refractory Materials

Zhang Caijun, Chen Huidi, Gao Aimin

2014, 35(1): 90-94. doi: 10.7513/j.issn.1004-7638.2014.01.018

Abstract(45) PDF(2)

Abstract:
By taking a six-strand tundish in a certain company as the research subject,the temperature field and flow field,and erosion of refractory materials of tundish were systematically analyzed by combination of numerical simulation and physical simulation.The calculation results show that changing the flow control devices in the tundish can effectively improve the flow of liquid steel,decrease temperature differential among all the tundish outlets,prolong the residence time of molten steel in the tundish,and reduce the erosion intensity of liquid steel on the refractory materials of the tundish,and thus extend the service life of tundish.

Laboratory Study on the Effect of Ultrasonic and Electric Impulse Discharging on Solidification Structures of Liquid Steel

Quan Shuli, Guo Zhaoqiao, Tao Linong

2014, 35(1): 95-100. doi: 10.7513/j.issn.1004-7638.2014.01.019

Abstract(34) PDF(0)

Abstract:
Ultrasonic sent from self -designed ultrasonic device was used to influence solidification structures of steel C45 in experiments,and electric impulse generated from pulsed magnetic field device was employed to influence spring steel 60Si2CrVA before casting and 40 s after casting respectively.The results show that the mechanical properties of steel C45 are noticeably improved after ultrasonic treatment.For spring steel 60Si2CrVA influenced with pulsed magnetic field of 5 Hz/200 V before casting,isometric crystal ratio of the cast ingot is greatly increased to 74% from 49% when untreated by the magnetic field, and isometric crystal sizes are significantly reduced to 0.4 mm from 1 mm.For spring steel 60Si2CrVA influenced 40 s after casting,isometric crystal ratio is increased,and isometric crystal sizes are reduced with the increase of influence time.

Experiments of Converter Dephosphorization with Single and Double Slag Processes

Zhou Chaogang, Li Jing, Wu He, Cai Kesen, Wu Guoping, Cao Yuliang

2014, 35(1): 101-106. doi: 10.7513/j.issn.1004-7638.2014.01.020

Abstract(50) PDF(0)

Abstract:
Based on industrial tests in Nan Steel,experiments were carried out to study the effect of single and double slag processes on dephosphorization of molten steel,the effect of different operating system on phosphorus content in molten steel,the effect of adding amount of auxiliary materials on phosphorus content in molten steel at the end point of smelting,and the effect of retained slag process on preliminary slag and phosphorus content in molten steel at the end point of smelting.The experimental results show that compared with the single slag process,the double slag process show better performance on dephosphorization in the preliminary stage,and it can fully meet the requirements of low phosphorus steel at the end point of smelting.In addition,the optimum smelting temperature,alkalinity,and FeO percentage etc.for low phosphorus steel smelting were determined in field tests.It can be concluded that it is better to smelt the steel which has strict requirements on phosphorus content with the double slag process.

Study on Desilication of Nb-bearing Hot Metal

Li Nan, Zhao Zengwu, Lu Husheng, Xu Zhangyin, Li Baowei

2014, 35(1): 107-111. doi: 10.7513/j.issn.1004-7638.2014.01.021

Abstract(33) PDF(0)

Abstract:
In order to extract niobium from Nb-bearing hot metal and obtain high-quality niobium slag,it is desired to reduce the silicon content in molten iron.Baotou Nb-bearing hot metal was smelted in 100 kW medium-frequency induction furnace by oxygen bottom blowing to study the selective oxidation of silicon and niobium during desilication.After reaction,the oxidization rates of silicon and niobium are 75.8% and 21.4% respectively with the molten iron temperature of 1 350℃ and slag basicity of 1.5, and the oxidization rates of silicon and niobium are 94.0% and 5.9% respectively with the molten iron temperature of 1 350℃ and slag basicity of 4.6.The study results show that high basicity slag restrains the removal of Mn,resulting in lower grade of niobium slag obtained by extracting Nb in the subsequent process.With the reaction temperature of 1 350℃ and slag basicity w_(CaO)/w_(SiO₂) of 1.5,the desilication limit of 0.15% is appropriate.

Study on Continuous Annealing Process of Low Carbon Steel on a Continuous Annealing /Hot-dip Galvanizing Dual-purpose Line

Zheng Zhiwang, Wang Minli

2014, 35(1): 112-118. doi: 10.7513/j.issn.1004-7638.2014.01.022

Abstract(53) PDF(0)

Abstract:
The annealing cycle of the continuous annealing/hot-dip galvanizing dual-purpose line is different from that of the typical continuous annealing line which has no slow cooling section in addition to short annealing cycle and low cooling rate after annealing.The industrially-produced full-hard low carbon steel coils under high coiling temperature during hot rolling were used to investigate the effect of annealing temperature and time as well as over-aging treatment on the microstructures and mechanical properties of typical low carbon steels according to the characteristics of the dual purpose line.The results show that ferrite grains of both the low carbon steel and the extra-low carbon steel are fine with a grain size number of 10.5 even when the annealing temperature reaches 810℃.After over-aging treatment for 240 s at 400℃,the strength of the low carbon steel is lowered by about 10 MPa and its elongation is increased with a maximum of 4.5% while the strength of the extra-low carbon steel is lowered by about 10 MPa only at an annealing temperature of 810℃ or above,namely,the effect of over-aging treatment is limited.Steel sheets with excellent mechanical properties have been produced by optimizing the continuous annealing process and on-line skin-passing process as well as micro-alloying with baron on a continuous annealing/hot-dip galvanizing dual-purpose line.

Research on Reducing the Thickness of Decarburized Layer of High-speed Rail

Yang Zongqiao, Zhao Zengwu, Li Yongzhi, Qin Liqiang

2014, 35(1): 119-122. doi: 10.7513/j.issn.1004-7638.2014.01.023

Abstract(47) PDF(0)

Abstract:
Based on field tests carried out during the manufacturing of high-speed steel rail in Baotou Rail and Beam Plant,effects of heating time and heating temperature on the thickness of decarburized layer of high-speed U71Mn rail are studied.Results show that in normal production,the thickness of the decarburized layer can be effectively decreased with tapping temperature of billets at 1 080~1 100℃ and uniform billet temperature.In the case of rolling delay for 15~30 min,by controlling the temperature of soaking zone and the temperature of sectionⅠof heating zone lower than 1 200℃ and 1 230℃ respectively,the production requirements can be satisfied and the thickness of the decarburized layer reduced.

2014, 35(1): 123-124.

Abstract(44) PDF(0)

Abstract:

2014 Vol. 35, No. 1