不同Mn含量低碳钢过冷奥氏体形变过程中的铁素体相变  

FERRITE TRANSFORMATION DURING DEFORMATION OF UNDERCOOLED AUSTENITE IN LOW CARBON STEELS WITH DIFFERENT Mn CONTENTS

作　　者：周荣锋[1] 杨王玥[1] 孙祖庆[2] 

机构地区：[1]北京科技大学材料科学与工程学院 [2]北京科技大学新金属材料国家重点实验室,北京100083

出　　处：《金属学报》2004年第1期1-7,共7页Acta Metallurgica Sinica

基　　金：国家重点基础研究发展规划资助项目 G1998061506

摘　　要：通过热模拟压缩实验,对C,Si含量基本相同、Mn含量不同的低碳钢过冷奥氏体在形变温度760℃,形变速率1/s条件下单向压缩变形过程中的组织演变进行研究,分析了Mn对低碳钢过冷奥氏体变形特征、转变动力学特征以及形变强化相变铁素体晶粒细化的影响。结果表明,Mn延迟低碳钢形变强化相变的进行,Mn含量提高,完成相变所需总应变相应提高,形变强化铁素体转变动力学可分三个阶段,随Mn含量增加,各阶段所需时间延长,应变提高,通过形变强化相变,Mn含量(质量分数,％)为0.48,0.84和1.29三种钢可获得平均晶粒截径分别为3.57±1.60,2.00±1.05和2.29±1.02μm的微细等轴铁素体晶粒以及第二组织弥散分布的复相组织。The microstructure evolution during deformation of undercooled austenite in three low carbon steels with much close contents of Si and C but different contents of Mn has been investigated by means of hot compression simulation experiment at 760 degreesC and strain rate of 1 s(-1). The effects of the content of Mn on the deformed behavior of undercooled austentie, the kinetics characteristics of deformation enhanced ferrite transformation and the ferrite grain size have been studied. It was found that the addition of Mn delays the transformation during deformation of undercooled austenite and higher true strain for the transformation is needed with increasing Mn content. Transformation kinetics can be divided into three stages, longer time and higher true strain are needed for each stages with increasing Mn content in the steels. Deformation enhanced transformation induces forming ultra-fine equiaxed ferrite grains with sizes of 3.57 +/- 1.60,2.00 +/- 1.05 and 2.29 +/- 1.02mum in steels with 0.48, 0.84 and 1.29 Mn respectively, and homogeneously distributed minor second phases.

关 键 词：低碳钢 形变强化相变 晶粒细化  Mn含量 转变动力学 

分 类 号：TG111.2[金属学及工艺—物理冶金] TG142.31[金属学及工艺—金属学]