激光螺旋点焊和电阻点焊DC06镀锌钢接头组织和性能  

Microstructure and properties of laser spiral spot welding and resistance spot welding DC06 galvanized steel joints

作　　者：周斌 陈捷狮 张杨[1,2] 张文帅[1,2] 杨尚磊 陆皓 ZHOU Bin;CHEN Jieshi;ZHANG Yang;ZHANG Wenshuai;YANG Shanglei;LU Hao(Shanghai University of Engineering Science,Shanghai 201602;Shanghai Collaborative Innovation Center of Laser Advanced Manufacturing Technology,Shanghai,201620;Shanghai Jiao Tong University,Shanghai,200240)

机构地区：[1]上海工程技术大学,上海201602 [2]上海市激光先进制造技术协同创新中心,上海201620 [3]上海交通大学,上海200240

出　　处：《焊接学报》2023年第6期41-49,I0005,I0006,共11页Transactions of The China Welding Institution

基　　金：国家自然科学基金(51805316);上海市科委专业技术服务平台(21DZ2294200);上海市科委地方高校能力建设项目(20030500900).

摘　　要：对比研究了激光螺旋点焊和电阻点焊工艺对DC06镀锌钢接头成形、微观组织和力学性能(显微硬度和剪切性能)的影响规律.结果表明,两种工艺均能获得成形良好的焊接接头,激光螺旋焊接头微观组织主要为铁素体(F)和少量渗碳体(Fe3C);电阻点焊接头微观组织主要为贝氏体(B)和铁素体(F).由于内外散热不均匀,激光螺旋点焊熔核区中心形成不同硬度的等轴晶,周围为具有明显取向的柱状晶,硬度值为130~160 HV10;电阻点焊熔核区冷速相近,无明显硬度梯度,硬度在190 HV10左右.激光螺旋点焊拉剪承载载荷为10.14 kN,比电阻点焊的8.82 kN提升了13.02%.接头失效形式分析发现:激光螺旋点焊和电阻点焊的失效形式分别为撕出型和拔出型,激光螺旋点焊由于热影响区组织塑性较好,接头受到拉剪作用时更易产生大角度转动而吸收更多的能量,具有更好的力学表现.最后,还对搭接间隙和锌镀层对激光螺旋点焊接头力学性能的影响进行讨论.The law of laser spiral spot welding and resistance spot welding process on DC06 galvanized steel joints forming,microstructure,and mechanical properties(microhardness and shear properties)was comparative studyed.The results show that both processes can obtain well-formed welded joints,the microstructure of the laser spiral welded head is mainly ferrite(F)and a small amount of carburized body(Fe3C);the microstructure of the resistance spot welded head is mainly bainite(B)and ferrite(F).Due to uneven heat dissipation inside and outside,the laser spiral spot welding nucleus formed in the center of the equiaxed crystals of low hardness,surrounded by columnar crystals with obvious orientation,hardness values of 130−160 HV;resistance spot welding nucleus area cold rate is similar,no obvious hardness gradient,hardness in about 190 HV.The laser spiral spot welding tensile shear load is 10.14 kN,which is 13.02%higher than the resistance spot welding 8.82 kN.The failure form of the joint was analyzed and found that the failure forms of laser spiral spot welding and resistance spot welding were tear-out types and pull-out type respectively.Finally,the effect of lap gap and zinc coating on the mechanical properties of laser spiral joint welds is also discussed.

关 键 词：镀锌钢板 激光螺旋点焊 电阻点焊 力学性能 可靠性 

分 类 号：TG456.7[金属学及工艺—焊接] TG47