Research and modeling on correlation among microstructure,yield strength and process of bainite/martensite steel  

作　　者：Jia-jia Qiu Min Zhang Gu-hui Gao Zhun-li Tan Bing-zhe Bai 

机构地区：[1]School of Mechanical,Electronic and Control Engineering,Materials Science and Engineering Research Center,Beijing Jiaotong University,Beijing 100044,China [2]Key Laboratory of Advanced Materials of Ministry of Education,School of Materials Science and Engineering,Tsinghua University,Beijing 100084,China

出　　处：《Journal of Iron and Steel Research International》2020年第7期834-841,共8页

基　　金：The research is supported by the National Key Research and Development Program of China(2017YFB0304504);Fund of Key Laboratory of Advanced Materials of Ministry of Education(No.XJCL201908);National Key Basic Research Program of China(2015CB654804).

摘　　要：The contributions of different strengthening mechanisms to yield strength of bainite/martensite multiphase rail steel with different finish cooling temperatures in the controlled cooling process were quantitatively investigated.Dislocation density and substructure size of the rail steel were measured by scanning electron microscopy,electron backscatter diffraction and X-ray diffraction.The results show that the dislocation density increases with the decrease in block width in rail steel.Based on the correlation among dislocation density,block width and yield strength,a physical model was proposed to predict the yield strength of rail steel.The variation of block width and dislocation density in different positions of rail head microstructure was integrated with temperature field simulation.Dislocation density and block width reveal significant correlations with the finish cooling temperature.

关 键 词：Bainite/martensite rail steel Temperature field simulation Controlled cooling process Yield strength Dislocation density 

分 类 号：TG142[一般工业技术—材料科学与工程]