钛微合金化热轧TRIP钢的连续冷却相变研究  

Transformation of Ti-microalloyed TRIP Steel During Continuous Cooling

作　　者：衣海龙[1] 徐薇[1] 龙雷周 刘振宇[1] 

机构地区：[1]东北大学轧制技术及连轧自动化国家重点实验室,沈阳110819

出　　处：《材料工程》2015年第3期7-11,共5页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目(51104046);中央高校基本科研业务费资助项目(N120407001;N120807001)

摘　　要：用Formastor-FII相变仪研究了钛微合金化TRIP在不同开冷温度下的连续冷却相变,建立了实验钢的连续冷却转变曲线,分析了铁素体、贝氏体及马氏体的相变规律。结果表明,随着冷却速率的增加,实验钢依次经过铁素体、贝氏体及马氏体相区,在较宽的冷却速率范围内,均可获得贝氏体及马氏体组织,其Ms点为450℃左右;随着开冷温度的降低或冷却速率的提高,实验钢的铁素体及贝氏体开始转变温度降低,抑制了铁素体及贝氏体相变;随着冷却速率的增加,实验钢的显微组织由铁素体+粒状贝氏体逐步转变为板条贝氏体+板条马氏体及板条马氏体组织;当冷却速率较低时,铁素体由晶内铁素体和晶界铁素体组成,晶内铁素体形核质点为复杂的氧化物及硫化物。The transformation behavior of a Ti-bearing microalloyed steel during continuous cooling at different start cooling temperatures was investigated by means of Formastor-FII phase transformation testing instrument. The continuous cooling transformation （CCT） curves were established, and the transformation behaviors of ferrite, bainite and martensite were analyzed. The results show that the ferrite, bainite and martensite are obtained successively with the increasing of cooling rate, and the bainite and martensite can be obtained in a wide range of cooling rate, and the martensite transforma- tion start temperature （Ms） is about 450~C. The ferrite and bainite transformation start temperature decreases with the decreasing of start cooling temperature or increasing of cooling rate, so the ferrite and bainite phase transformation is inhibited. The microstructure of the steel transforms from ferrite plus granular bainite, lath bainite plus lath martensite and then to lath martensite successively with the increasing of cooling rate; when the cooling rate is low, the ferrite is composed intragranular fer- rite and grain boundary ferrite, and the intragranular ferrite nucleat on complex oxide and sulfide.

关 键 词：热轧TRIP钢 连续冷却转变曲线 晶内铁素体 贝氏体 

分 类 号：TG115.213[金属学及工艺—物理冶金]