残余奥氏体对新型高碳Q-P-T钢疲劳性能的影响
Effect of retained austenite on the fatigue performance of novel high carbon quenching-partitioning-tempering steel
秦盛伟 1朱志民 1马海洋 1王广瑞 1周洋1
作者信息
- 1. School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,China
- 折叠
摘要
本文研究了残余奥氏体对Fe-0.65C-1.5Mn-1.5Si-0.6Cr-0.05Nb(wt%)淬火-配分-回火(Q-P-T)钢疲劳性能的影响.通过X射线衍射、扫描电子显微镜和透射电子显微镜表征了马氏体和残余奥氏体中微观结构的演变,包括不同循环周次下的体积分数和平均位错密度.与传统的淬火&回火(Q&T)钢相比,Q-P-T工艺使碳从过饱和马氏体配分到相邻的残余奥氏体中,从而保留更多的残余奥氏体.经Q-P-T处理后,钢的抗拉强度略有下降,但其伸长率与强塑积分别提高了287%和234%.与Q&T钢的疲劳极限为550 MPa相比,Q-P-T钢的疲劳极限达到了650 MPa,提高了100 MPa(18.2%).高碳Q-P-T钢具有更高疲劳性能的机理主要源于两个方面:一是疲劳试验中存在残余奥氏体吸收位错效应(DARA效应),显著增强了马氏体基体的变形能力;另一方面是残余奥氏体相变产生的高硬度小尺寸马氏体的疲劳止裂效应.本工作证实了高碳Q-P-T钢在循环拉压载荷下存在DARA效应,进一步将该效应的应用范围从静载荷推广至循环变载荷.
Abstract
The effect of retained austenite on the fatigue property of a novel Fe-0.65C-1.5Mn-1.5Si-0.6Cr-0.05Nb(wt.%)quenching-partitioning-tempering(Q-P-T)steel was investigated.X-ray diffraction,scanning electron microscopy,and transmission electron microscopy were performed to characterize the evolution of microstructure including retained austenite fraction and average dislocation densities in both martensite and retained austenite.Compared with traditional quenching and tempering(Q&T)steel,Q-P-T steel contains much more retained austenite by partitioning of carbon from supersaturated martensite to retained austenite.After Q-P-T,the tensile strength decreases slightly,while the elongation and the product of strength and elongation(PSE)improved 287%and 234%,respectively.The fatigue limit of Q-P-T steel(650 MPa)is increased by 100 MPa(18.2%)compared with Q&T steel(550 MPa).The mechanism of high fatigue performance for high-carbon Q-P-T steel is mainly stemmed from two aspects:one is the dislocation absorption of the retained austenite(DARA)effect existing in the fatigue test,which significantly enhances the deformation ability of martensite matrix;the other is the deformation-induced martensitic transformation effect which can effectively arrest crack to against fatigue.This work verifies the existence of DARA effect in high carbon Q-P-T steel under cyclic tension and compression loading and makes the third-generation advanced high-strength steels extend to the field of cyclic variable loads from static loads.
关键词
淬火-配分-回火工艺/残余奥氏体吸收位错效应/残余奥氏体/疲劳行为Key words
Q-P-T process/DARA effect/retained austenite/fatigue behavior引用本文复制引用
基金项目
National Natural Science Foundation of China(52001281)
Key Scientific and Technological Research Projects in Henan Province,China(192102210012)
Natural Science Foundation of Henan Province,China(202300410431)
出版年
2023
NETL
NSTL
维普
万方数据