热镀锌TRIP钢点焊焊接裂纹分析  

Hot dip galvanized TRIP steel spot welding crack analysis

作　　者：贾松青[1] 张永强[1] 刘兴全[1] 王威[1] 

机构地区：[1]首钢技术研究院,北京100043

出　　处：《电焊机》2015年第8期145-149,共5页Electric Welding Machine

摘　　要：热镀锌TRIP钢具有强度高和韧性好的优点,是汽车轻量化的理想材料,广泛应用于汽车制造领域。针对1.2 mm厚的热镀锌钢板TRIP590+Z和TRIP690+Z进行电阻点焊焊接裂纹分析,目标是研究裂纹形成的原因,对焊接质量的影响。试验对比两个钢种的可焊电流窗口和焊接接头金相组织;通过扫描电镜对裂纹进行杂质元素分析,对两个钢种的焊接接头进行抗剪试验、硬度试验,并对比焊接接头的力学性能。试验结果表明,基板强度高的材料减薄情况要优于基板强度低的材料,边缘间隙是主要的应力集中点,是裂纹产生的开裂源。Hot dip galvanized TRIP steel,with high strength and good toughness,as the ideal material of car light weight,were widely used in the field of automobile manufacturing. This paper used resistance point welding of 1.2 mm TRIP590＋Z and TRIP690＋Z hotdip galvanized strips to study the causes of crack formation on resistance spot welding process. The test compared the welding current rang and microstructure. SEM was used to analyze the impurity elements. Shear test,microhardness test were done to compare the mechanical properties of welding and the affecting factors of welding process. Through the analysis,the more thickness of zinc layer,the smaller the welding current rang. The welding current of big thickness was about 23% smaller than that of small thickness. The big thickness of Zinc layer could also cause the electrode wear serious,and the cap life in endurance test came down from 1000 points to 800 points. Material thinning of high strength was superior than that of low strength material,the point of stress concentration was the edge of the nugget,and it was the source of crack.

关 键 词：热镀锌钢 点焊 冷裂纹 

分 类 号：TG453.9[金属学及工艺—焊接]