焊后热处理对4Cr5MoSiV模具钢修补焊接头组织和性能的影响  

Effect of post weld heat treatment on microstructure and properties of repair welded joints of 4Cr5MoSiV die steel

作　　者：徐和林 王江华 Xu Helin;Wang Jianghua(Southwest Jiaotong University Hope College,Chengdu Sichuan 610400,China;School of Mechanical Engineering,Sichuan University,Chengdu Sichuan 610065,China)

机构地区：[1]西南交通大学希望学院,四川成都610400 [2]四川大学机械工程学院,四川成都610065

出　　处：《金属热处理》2025年第3期64-68,共5页Heat Treatment of Metals

基　　金：四川省重点研发计划(2023YFG0166);国家自然科学基金青年基金(61603238)。

摘　　要：采用TIG焊对4Cr5MoSiV模具钢进行修补焊,并对其进行淬火和调质的焊后热处理,利用扫描电镜、显微硬度计和拉伸试验机对3种状态(焊态、淬火态和调质态)接头的组织、硬度和拉伸性能进行观察和测量。结果表明,焊态下焊缝组织主要为粗大的马氏体、奥氏体与析出碳化物。淬火处理后的焊缝组织主要为马氏体。调质处理后的焊缝组织主要为回火马氏体和少量的析出碳化物。焊态试件的焊缝区硬度平均值约648.7 HV0.1;淬火态试件的焊缝区硬度有所上升,平均值约670.1 HV0.1;调质态试件的焊缝区硬度值下降,约为481.7 HV0.1,与母材区硬度接近,且硬度均匀。接头经焊后热处理后抗拉强度和伸长率均得到显著提升,其中调质态接头抗拉强度和伸长率达到1270 MPa和11.3%,比焊态分别提升了29%和30%。Repair welding was performed on 4Cr5MoSiV die steel by using TIG welding,followed by post weld heat treatment of quenching and quenching and tempering.The microstructure,hardness,and tensile properties of the joints in three states(welded,quenched and quenched and tempered)were observed and measured by means of scanning electron microscope,microhardness tester,and tensile testing machine.The results indicate that the weld seam microstructure in as-welded state is mainly composed of coarse martensite,austenite,and precipitated carbides.After quenching the weld seam microstructure is mainly martensite,while its microstructure in the quenched and tempered state is mainly tempered martensite and a small amount of precipitated carbides.The average hardness of the weld zone in the as-welded specimens is about 648.7 HV0.1.The hardness of the weld zone in the quenched specimens increases,with an average value of about 670.1 HV0.1,and the hardness is uniform.The hardness value of the weld zone in the quenched and tempered specimens decreases to about 481.7 HV0.1,which is close to that of the base metal zone,and the hardness is also uniform.After post weld heat treatment,both the tensile strength and elongation of the joints are significantly improved.Among them,the tensile strength and elongation of the quenched and tempered joint reach 1270 MPa and 11.3%,which are 29%and 30%higher than those of the as-welded joint,respectively.

关 键 词：4Cr5MoSiV模具钢 修补焊 焊后热处理 组织 力学性能 

分 类 号：TG156.1[金属学及工艺—热处理]