摘要
采用高温激光共聚焦显微镜(HT-CLSM)原位动态观察的方法,通过对动态视场下马氏体浮凸和贝氏体浮凸的鉴别,研究了含铜钢奥氏体连续冷却过程中的组织转变规律和相变点测定方法。结果表明,冷却速度由5℃/s升至20℃/s,试样的组织逐渐由贝氏体变为板条马氏体。HT-CLSM动态观察过程中,贝氏体形成速度慢,生长过程中伴有"互锁"现象,产生的浮凸较浅;随着冷速的升高,产生的马氏体浮凸有爆发性和阶段性趋势,多为成束状平行分布,且马氏体浮凸较深。当冷却速率为20℃/s时,动态观察下以成束马氏体形成为判据,测得Ms点为447.6℃,室温下组织为板条马氏体,显微硬度达到301 HV10,与其他方法测定结果相近。
By using in-situ dynamic microstructure observation with high temperature confocal laser scanning microscope(HT-CLSM), and through identification of martensite relief and bainite relief under the dynamic view field, the microstructure transformation law and phase transformation point determination method of Cu-bearing steel austenite during continuous cooling were studied. The results show that as the cooling rate increases from 5 ℃/s to 20 ℃/s, the microstructure of the specimen gradually changes from bainite to lath martensite. During the dynamic observation process of HT-CLSM, the bainite formation rate is slow, and the growth process is accompanied by the “interlocking” phenomenon, resulting in shallow relief. As the cooling rate increases, the martensite relief produced has an explosive and staged trend, mostly in bundles and parallel distribution, and the martensite relief is deeper. When the cooling rate reaches to 20 ℃/s, by using the formation of bundled martensite under dynamic observation as the criterion, the Ms point is measured as 447.6 ℃. The microstructure is lath martensite at room temperature, meanwhile the microhardness is as high as 301 HV10, which is similar to the measurement result of other methods.
作者
吕金峄
张义伟
罗小兵
袁晓敏
Lü Jinyi;Zhang Yiwei;Luo Xiaobing;Yuan Xiaomin(School of Materials Science and Engineering,Anhui University of Technology,Maanshan Anhui 243002,China;Research Institute of Structural Steels,Central Iron and Steel Research Institute,Beijing 100081,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2022年第1期19-24,共6页
Heat Treatment of Metals
基金
安徽省高校自然科学研究项目(KJ2016A807)。
关键词
高温激光共聚焦显微镜(HT-CLSM)
含Cu钢
连续冷却
相变点
high temperature confocal laser scanning microscope(HT-CLSM)
Cu-bearing steel
continuous cooling
phase transition point
