车厢结构用冷轧马氏体钢电阻点焊工艺性能研究  

Research on Process Performance of Resistance Spot Welding of Cold Rolled Martensitic Steel with Different Strength

作　　者：王鹏博 张永强 惠亚军 王泽阳 伊日贵 王晓雄 张郢[2] WANG Pengbo;ZHANG Yongqiang;HUI Yajun;WANG Zeyang;YI Rigui;WANG Xiaoxiong;ZHANG Ying(Research Institute of Technology of Shougang Group,Beijing 100043,China;Shougang Jingtang Iron and Steel Co.,Ltd.,Tangshan 063200,China)

机构地区：[1]首钢集团有限公司技术研究院,北京100043 [2]首钢京唐钢铁联合有限责任公司,河北唐山063200

出　　处：《电焊机》2024年第5期117-123,共7页Electric Welding Machine

摘　　要：为评估和对比1.2 mm厚的SCR1000和SCR1200冷轧马氏体钢的电阻点焊工艺性能,采用OBARA DB-220型点焊机进行电阻点焊试验,对比了两个钢种的焊接电流窗口、焊点破坏模式、力学性能、金相组织、疲劳性能。研究结果表明:随着钢材强度的提升,整体焊接电流窗口逐渐向左侧偏移,SCR1200达到最小焊核直径、焊接飞溅的焊接电流均小于SCR1000;SCR1200上限电流焊点剪切力比SCR1000提升了8.9%,而SCR1000的焊点韧性较好,其断口韧窝更细小和密集;相对熔核区和母材区,SCR1000、SCR1200的点焊接头的热影响区出现了明显的软化区,但SCR1200的软化区硬度略高。在相同载荷下,SCR1200的疲劳寿命高于SCR1000,点焊接头的疲劳强度随着钢板强度的增加而提高。To evaluate and compare the resistance spot welding process performance of 1.2 mm thick SCR1000 and SCR1200 cold-rolled martensitic steels,resistance spot welding experiments were conducted using the OBARA DB-220 type spot welder.The study compared the welding current window,joint failure mode,mechanical properties,microstruc‐ture,and fatigue performance of the two steel grades.The results indicate that as the steel strength increases,the overall welding current window gradually shifts to the left,with SCR1200 achieving a smaller minimum weld core diameter and a lower welding current for spatter compared to SCR1000;the shear force of the upper limit current weld point for SCR1200 is 8.9%higher than that for SCR1000.Relative to the molten core area and base metal area,the heat-affected zone of the spot-welded joints for both SCR1000 and SCR1200 exhibited a noticeable softening zone,but with SCR1200 having a slightly higher softening zone hardness.Under the same load,the fatigue life of SCR1200 is higher than that of SCR1000,and the fatigue strength of the spot-welded joints increases with the increase in steel plate strength;the weld point toughness of SCR1000 is better,with finer and more compact dimples at the fracture surface.

关 键 词：马氏体钢 电阻点焊 电流窗口 力学性能 疲劳性能 

分 类 号：TG457.11[金属学及工艺—焊接]