摘要
对Ti-V-Mo复合微合金钢进行热模拟实验,先将其加热至1250℃,保温180s后冷却至890℃,保温一定时间并进行压缩变形随后冷却至不同的终冷温度,最后水冷至室温。采用光学显微镜(OM)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和维氏硬度计等手段对其表征,研究了终冷温度对其析出相、组织和硬度的影响。结果表明,终冷温度为590℃时实验钢的组织为粒状贝氏体,终冷温度为630~690℃时其组织为多边形铁素体,终冷温度为730℃时其组织为铁素体和马氏体。随着终冷温度的提高,钢中铁素体的平均晶粒尺寸由2.7μm增大到5.6μm,(Ti,V,Mo)C析出相的平均尺寸由3.45nm增大到4.71nm。随着终冷温度由590℃提高到730℃其硬度升高后保持平稳再极快地降低。终冷温度为630~660℃时其硬度最高为485HV,因为铁素体的细晶强化和(Ti,V,Mo)C的沉淀强化趋于饱和。实验钢中铁素体晶粒尺寸改变引起的细晶强化和(Ti,V,Mo)C的析出引起的沉淀强化,是其硬度变化的主要原因。
A Ti-V-Mo composite microalloyed experimental steel was subjected to series heating-de-formation treatment via Gleeble-3800 thermal simulation tester,i.e.firstly it was heated to 1250℃and kept for 180 s,then cooled down to 890℃and kept for a certain period of time;Subsequently,compres-sion and deformation treatments were carried out;Afterwards,it was cooled to different(final cooling)temperatures and finally water-quenched.The effect of final cooling temperature on the precipitates,mi-crostructure transformation,and hardness of the steel was systematically studied using optical micros-copy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and Vickers hardness tester.The precipitation behavior of carbides(Ti,V,Mo)C and its influence on the variation of microstructure and hardness of the steels quenched at different final cooling temperatures were clari-fied.The results indicated that the microstructure of the test steels consist of granular bainite at 590℃,polygonal ferrite at temperatures ranging from 630℃to 690℃and a mixture of ferrite and martensite at 730℃.With the increasing final cooling temperature,the average grain size of ferrite increased from 2.7μm to 5.6μm,and the average size of(Ti,V,Mo)C precipitates increased from 3.45 nm to 4.71 nm.With the increasing final cooling temperature from 590°C to 730°C,the hardness increased first,then remain sta-ble and then decreased rapidly.For the isothermal final cooling temperature within the range 630~660℃,the hardness was up to 485HV,which was due to the saturation of the fine grain strengthening of ferrite and the precipitation strengthening of(Ti,V,Mo)C.The fine grain strengthening caused by ferrite grain re-finement and the precipitation strengthening caused by the precipitation of(Ti,V,Mo)C were dominant factors of hardness change at different final cooling temperatures.
作者
韩杨燚
张腾昊
张可
赵时雨
汪创伟
余强
李景辉
孙新军
HAN Yangyi;ZHANG Tenghao;ZHANG Ke;ZHAO Shiyu;WANG Chuangwei;YU Qiang;LI Jinghui;SUN Xinjun(School of Metallurgical Engineering,Anhui University of Technology,Ma'anshan 243032,China;Institute for Tructural Steels,Central Iron and Steel Research Institute Co.,Ltd.,Beijing 100081,China;Long Products Business Division,Ma'anshan Iron and Steel Co.,Ltd.,Ma'anshan 243003,China;Pangang Group Research Institute Co.,Ltd.,Panzhihua 617000,China;Hunan Hualing Lianyuan Iron and Steel Co.,Ltd.,Technical Center,Loudi 4ll101,China)
出处
《材料研究学报》
北大核心
2025年第7期533-541,共9页
Chinese Journal of Materials Research
基金
国家自然科学基金(52474340)
安徽省高等学校科学研究项目(2023AH051090)。
关键词
金属材料
终冷温度
Ti-V-Mo复合微合金钢
组织
析出相
硬度
metallic materials
final cooling temperature
Ti-V-Mo complex microalloyed steel
micro-structure
precipitation
hardness
