冷作模具钢SDC55的Q-P-T性能和微观组织研究

来源期刊：上海金属2011年第4期

论文作者：陈卓 邓黎辉 熬影 汪宏斌 吴晓春

文章页码：10 - 14

关键词：冷作模具钢； Q-P-T处理； 微观组织； 残余奥氏体

Key words：Cold Work Die Steel； Quenching-Partitioning-Tempering(Q-P-T) Process； Microstructure； Retained Austenite

摘    要：主要研究和探索了对新型冷作模具钢SDC55处理的Q-P-T工艺及其微观组织,测试了不同Q-P-T工艺下SDC55试样的硬度、冲击韧性以及残余奥氏体的含量和稳定性,用TEM观察Q-P-T处理后试样的微观组织。实验结果表明,SDC55的优化工艺为930℃奥氏体化,290℃PT温度时间2 min,最后经过180℃一次2 h回火。与常规的淬、回火工艺(930℃奥氏体化淬火,180℃回火两次,每次2 h)相比较,经过Q-P-T处理之后,SDC55的韧性从123 J提高到131 J,硬度保持不变,均为60 HRC。对微观组织和残余奥氏体分析发现,经Q-P-T处理后SDC55的残余奥氏体稳定性得到提高,从而使材料的冲击韧性提高。

Abstract: The microstructure and properties of a newly developed cold working die steel SDC55 treated by Quenching-Partitioning-Tempering(Q-P-T) process was studied.The hardness and toughness of the samples after treatment was studied,as well as the content and stability of austenite.The microstructure of SDC55 processed by Q-P-T was characterized by transmission electron micrograph(TEM) and X-ray diffraction(XRD) respectively.It is shown that,the parameters of Q-P-T suited for SDC55 were austenization at 930 ℃,PT treatment at 290 ℃ for 2 min,then tempering at 180 ℃ once for 2 h.Compared with the normal quenching and tempering treatment,the toughness of SDC55 after Q-P-T treatment increased from 123 J to 131 J,and the hardness remained 60 HRC.The microstructure analysis showed that the stability of austenite increased after processed by Q-P-T,which was the key reason why the toughness of SDC55 increased.