热处理工艺对3种不同Cr系冷作模具钢热处理变形的影响  

Effect of heat treatment process on heat treatment deformation of three different Cr series cold working die steels

作　　者：毛宏 吴红庆 涂宇杰 吴晓春 MAO Hong;WU Hong-qing;TU Yu-jie;WU Xiao-chun(School of Materials Science and Engineering,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,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：《材料热处理学报》2024年第8期154-163,共10页Transactions of Materials and Heat Treatment

基　　金：省部共建高品质特殊钢冶金与制备国家重点实验室自主课题(SKLASS 2022-Z12)。

摘　　要：精冲模在服役过程中受较大的循环载荷导致的变形会增加其维修成本并缩短模具寿命。综合考量精密模具在热处理过程中产生的形变因素,相变引起的体积膨胀更受关注。设计出了一种新型“井”字型变形模块,研究了D2、DC53和7Cr5Mo2V 3种冷作模具钢在不同真空热处理工艺下相变引起的尺寸变化规律。结果表明:在1030℃淬火后,DC53钢的最大形变率约为0.65%;在210℃低温回火和520℃高温回火后,7Cr5Mo2V钢的最大形变率分别约为1.04%和1.81%。影响模具热处理变形的因素是残留奥氏体含量、二次碳化物析出的量和马氏体特征参数等。经210℃低温回火后,7Cr5Mo2V、D2和DC53钢的残留奥氏体体积分数分别为14.44%、13.21%和11.43%;520℃高温回火后,残留奥氏体体积分数均显著减少,分别为6.04%、3.39%和2.53%。The deformation caused by large cyclic loads during the service process of precision stamping molds will increase their maintenance costs and shorten their lifespan.Taking into account the deformation factors generated during the heat treatment of precision molds,the volume expansion caused by phase transformation is of greater concern.A new type of"well"shaped deformation module was designed,and the size changes caused by phase transformation of D2,DC53 and 7Cr5Mo2V three cold working die steels under different vacuum heat treatment processes were studied.The results show that after quenching at 1030℃,the maximum deformation rate of the DC53 steel is about 0.65%.After low-temperature tempering at 210℃and high-temperature tempering at 520℃,the maximum deformation rates of the 7Cr5Mo2V steel are about 1.04%and 1.81%,respectively.The factors that affect the deformation of the mold during heat treatment are the retained austenite content,the amount of secondary carbide precipitation and the characteristic parameters of martensite.After low-temperature tempering at 210℃,the volume fractions of the retained austenite in the 7Cr5Mo2V,D2 and DC53 steels are 14.44%,13.21%and 11.43%,respectively.After high-temperature tempering at 520℃,the volume fractions of the retained austenite significantly decrease,which are 6.04%,3.39%and 2.53%,respectively.

关 键 词：冷作模具钢 “井”字型模块 热处理变形 残留奥氏体 

分 类 号：TG142.3[一般工业技术—材料科学与工程]