SLD-MAGIC冷作模具钢的热处理微畸变特性及其机理  

Heat treatment microdistortion characteristics and mechanism of SLD-MAGIC cold working die steel

作　　者：吴红庆 毛宏 邓志鹏[1,2] 宁辉 吴晓春 Wu Hongqing;Mao Hong;Deng Zhipeng;Ning Hui;Wu Xiaochun(School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China;State Key Laboratory of Advanced Special Steel,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学材料科学与工程学院,上海200444 [2]上海大学省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444

出　　处：《金属热处理》2024年第3期128-135,共8页Heat Treatment of Metals

基　　金：国家重点研发计划(2016YFB0300403);模具钢选材和用材技术的标准化研究(SKLASS 2021-11)。

摘　　要：采用真空热处理炉测试了SLD-MAGIC和DC53冷作模具钢样块在1030℃淬火、及210℃回火和520℃回火3种热处理条件下尺寸的畸变率,并结合X射线衍射仪(XRD)、扫描电镜(SEM)、高精度差分膨胀仪、JMatPro软件等手段对微观结构、马氏体的特征参数、残留奥氏体含量、回火碳化物含量等进行分析。结果表明,SLD-MAGIC钢和DC53钢样块经上述3种热处理后体积膨胀,尺寸畸变率范围在0.02%~0.12%之间,DC53钢在同等热处理条件下平均尺寸畸变率约为SLD-MAGIC钢的1.9~2.2倍;SLD-MAGIC钢25~700℃以上的平均热膨胀系数比DC53钢的低0.15×10^(-6)℃^(-1);SLD-MAGIC钢的马氏体碳含量和晶格常数分别为1.34%、2.8894×10^(-10)m,都比DC53钢小;并且热处理后的残留奥氏体含量和回火碳化物含量都比DC53钢少,因此SLD-MAGIC钢比DC53钢的尺寸膨胀效应更小,SLD-MAGIC钢具有热处理微畸变特性。Vacuum heat treatment furnace was used to test the dimensional distortion rate of SLD-MAGIC and DC53 cold working die steel specimens under three heat treatment conditions of quenching at 1030℃,tempering at 210℃and tempering at 520℃,and combined with X-ray diffractometer(XRD),scanning electron microscope(SEM),high-precision differential dilatometer,JMatPro software to analyze the microstructure,characteristic parameters of martensite,the content of retained austenite and the content of secondary carbides.The results show that the volumes of the SLD-MAGIC and DC53 steel specimens expand after the three heat treatments,and their dimensional distortion rates range from 0.02%to 0.12%.The average dimensional distortion rate of the DC53 steel is about 1.9 to 2.2 times that of the SLD-MAGIC steel under the same heat treatment conditions.The average thermal expansion coefficient of the SLD-MAGIC steel from 25℃to 700℃ is 0.15×10^(-6)℃^(-1)lower than that of the DC53 steel,the carbon content and lattice constant of the martensite of the SLD-MAGIC steel are 1.34%and 2.8894×10^(-10)m,respectively,which are smaller than that of the DC53 steel.The content of retained austenite and the content of secondary carbide of SLD-MAGIC steel after heat treatment are less than that of the DC53 steel.Therefore,the size expansion effect of the SLD-MAGIC steel is smaller than that of the DC53 steel,and the SLD-MAGIC steel has the characteristic of heat treatment microdistortion.

关 键 词：SLD-MAGIC冷作模具钢 热处理微畸变 马氏体 残留奥氏体 回火碳化物 

分 类 号：TG142.45[一般工业技术—材料科学与工程]