Q&P980超高强钢电阻点焊接头的组织性能分析  

Microsturcture and Mechanical Properties of Resistance Spot Welded Joint of Q&P980 Ultra High Strength Steel

作　　者：贾坤宁[1] 杨海峰 王华 JIA Kunning;YANG Haifeng;WANG Hua(School of Mechanical and Electrical Engineering,Changchun Institute of Technology,Changchun 130012,China;Shandong Provincial Key Laboratory of Special Welding Technology,Harbin Institute of Technology at Weihai,Weihai 264209,China)

机构地区：[1]长春工程学院机电学院,吉林长春130012 [2]哈尔滨工业大学(威海)山东省特种焊接重点实验室,山东威海264209

出　　处：《热加工工艺》2024年第7期67-70,共4页Hot Working Technology

基　　金：吉林省教育厅“十三五”科学技术项目(JJKH20200613KJ)

摘　　要：以1 mm厚的Q&P980钢板为对象,研究了其电阻点焊接头的成形、微观组织及力学性能。结果表明:当焊接电流为12.5 kA,焊接时间为10 cyc,电极压力为0.3 MPa时,点焊试件表面成形良好,无外部飞溅,仅存在轻微的内部飞溅。熔核区微观组织为粗大的板条状马氏体,粗晶、细晶热影响区组织主要为板条状马氏体及少量铁素体,板条状马氏体尺寸小于熔合区,这些区域的硬度均大于母材区的;双相热影响区因存在少量回火马氏体,出现了轻微的软化。焊接件的拉剪失效形式为纽扣断裂,断口可分为启断区、扩展区、瞬断区,启断区发生混合断裂,扩展区和瞬断区发生韧性断裂。Taking the 1mm thick Q&P980 steel plate as the object,the appearance,microstructure and mechanical properties of the resistance spot welded joint were investigated.The results show that when the welding current is 12.5 kA,welding time is 10 cyc,the electrode pressure is 0.3 MPa,the appearance of the spot welded specimen is good without external splash,and it only has slight internal spatter.The microstructure of the fusion zone is coarse lath martensite,and the microstructure of the coarse grain and fine grain heat affected zones is lath martensite,a small quantity of ferrite,and the lath martensite size is smaller than that of the fusion zone.The microhardness of the above zones is obviously higher than that of the base metal.The intercritical heat affected zone has a small amount of tempered martensite,which results in slight softening.The tensile fracture mode of the welded specimen is button fracture,the fracture is divided to crack initiation zone,crack extension zone and transient crack zone.Mixed fracture occurs in the crack initiation area,and ductile fracture occurs in crack extension zone and transient crack zone.

关 键 词：Q&P980钢 电阻点焊 焊点成形 微观组织 力学性能 

分 类 号：TG453.9[金属学及工艺—焊接]