摘要
作为第三代汽车钢的一种,淬火-碳配分-回火(Q-P-T)工艺制备的高强度钢显微组织由先形成马氏体、新鲜马氏体和残余奥氏体构成.本文利用激光共聚焦显微镜,观察了一次淬火时马氏体和未转变奥氏体分布的不均匀形成过程.在此基础上,进一步表征了在不均匀的基体中,Q-P-T工艺获得的马氏体具有多尺度的分布特征;同时,二次淬火获得的新鲜马氏体具有:1)更细的板条尺寸;2)在一个块状区域内具有相同的取向,可视为一个"packet";3)更高的力学性能.研究结果客观地展示了Q-P-T制备高强度钢的微观组织演化本质,为进一步改进Q-P-T工艺、提高性能提供了准确的理论依据.
The advanced high strength steels（AHSS） for auto manufacturing have been developed to the 3rd generation. The typical one is steel treated by Q-P-T process, which consists of the prior martensite, fresh martensite and retained austenite. In this paper, the non-uniform distributive formation of martensite and untransformed austenite during the one-step quenching treatment was observed by laser scanning confocal microscope. For the Q-P-T process, the non-uniform distributions of untransformed austenite, prior martensite and segmented austenitic grains are the main reasons to form the multi-scale martenite. Moreover, the fresh martensite possesses three highlights, such as microstructure of finer laths, same orientation in a blocky area considered as a ＂packet＂ and higher mechanical properties. The research result of this paper reveals the microstructure evolution of Q-P-T treated steel, and provides the accurate theoretical basis for improving the Q-P-T process and the mechanical properties.
出处
《中国科学：技术科学》
EI
CSCD
北大核心
2015年第7期714-720,共7页
Scientia Sinica(Technologica)
基金
国家重点基础研究发展计划(批准号:2010CB630803)
国家自然科学基金(批准号:51101036
51201093
11472072)
辽宁省自然科学基金(批准号:2014028001)资助项目
关键词
Q-P-T工艺
马氏体相变
激光共聚焦
残余奥氏体
力学性能
Q-P-T process
martensite tranformation
laser scanning confocal microscope
retained austenite
mechanical properties
