热处理工艺对M390/304闪光对焊焊接接头微观组织及力学性能的影响  

Effect of Heat Treatment Process on Microstructure and Mechanical Properties of M390/304 Flash Butt Welding Welded Joints

作　　者：董浩[1,2] 乔丽学 曹睿 王彩芹[1,2] 车洪艳[1,2] 王铁军 闫英杰[3] DONG Hao;QIAO Lixue;CAO Rui;WANG Caiqin;CHE Hongyan;WANG Tiejun;YAN Yingjie(Advanced Technology&Materials Co.,Ltd.,China Iron&Steel Research Institute Group,Beijing 100081,China;Hebei Technology Innovation Center of Hot Isostatic Pressing,Zhuozhou 072750,Hebei,China;The State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]中国钢研科技集团有限公司,安泰科技股份有限公司,北京100081 [2]河北省热等静压技术创新中心,河北涿州072750 [3]兰州理工大学材料科学与工程学院,有色金属先进加工与再利用省部共建国家重点实验室,兰州730050

出　　处：《材料导报》2023年第24期192-197,共6页Materials Reports

基　　金：国家自然科学基金(52175325,51961024,52071170)。

摘　　要：本工作基于提高M390高碳马氏体不锈钢与304奥氏体不锈钢焊接接头的力学性能并且使M390/304焊接接头达到高端刀具的硬度要求,对闪光对焊的M390/304焊接接头进行不同热处理工艺研究。实验采用拉伸、维氏显微硬度测试及扫描电镜(SEM)表征不同热处理工艺的焊接接头的力学性能及微观组织演变,并通过线扫描研究了不同热处理工艺下焊接接头的元素扩散,揭示了不同热处理工艺下焊接接头的断裂机理。研究结果表明,1150℃空冷热处理工艺为M390/304闪光对焊焊接接头的最佳热处理工艺,对应的抗拉强度和延伸率分别为494 MPa和15.7%,分别比焊态提高了2.7%和182%。延伸率显著提高是由于在1150℃空冷工艺下焊接接头的元素扩散程度较大,焊缝中化学成分的均匀性得到提高。不同热处理工艺下焊接接头的断裂类型均为脆性断裂,但断裂位置并不相同。断裂位置的变化是由于不同热处理工艺下C、Cr、Ni等元素的扩散程度不同,焊缝中碳化物的尺寸和形貌也不同,导致焊缝中第二相强化作用不同。In order to improve the mechanical properties of M390 high carbon martensitic stainless steel and 304 austenitic stainless steel welded joints,especially the hardness of welded joints to meet the requirements of advanced knives production,different heat treatment processes of welded joints were performed for M390 high carbon martensitic stainless steel and 304 austenitic stainless steel joints obtained by flash butt welding.Tensile,Vickers microhardness tests and scanning electron microscopy(SEM)were used to characterize the mechanical properties and microstructure evolution of welded joints with different heat treatment processes,line scanning was used to investigate element diffusion in various heat treatment processes and the fracture mechanism of welder joints under different heat treatment processes was investigated.The research results show that the 1150℃air cooling heat treatment process can be used as the best heat treatment process for M390/304 welded joints,the tensile strength and elongation of the corresponding welded joints reach 494 MPa and 15.7%,which increase by 2.7%and 182%compared to as-welded,respectively.The greater degree of element diffusion in welded joint under 1150℃air cooling process,as well as the improved uniformity of chemical composition in weld metal,account for the significant increase in elongation.The fracture types are all brittle fractures under different heat treatment processes,but the fracture locations are not the same.The change in fracture location is caused by different diffusion degrees of C,Cr,Ni elements during different heat treatment processes,as well as differences in the size and morphology of carbides in weld metal,which result in different strengthening effects of the second phase in weld metal.

关 键 词：M390/304焊接接头 闪光对焊 淬火工艺 微观组织 力学性能 

分 类 号：TG156[金属学及工艺—热处理]