D6A+20钢自动焊焊缝射线检测及裂纹成因分析

X-ray test of D6A+20 steel weld by automatic welding and analysis on mechanism of crack initiation

关键词:  异种金属  自动焊  焊缝  射线检测  焊接裂纹

Key words:  dissimilar metal  automatic welding  weld  X-ray test  welding crack

摘要:

针对D6A+20钢异种金属机器人自动焊焊缝质量的射线检测问题,从焊接结构入手,合理安排射线检测工艺,在缺陷评定中排除焊缝成形干扰,实现了该椭圆多层焊缝的高质量检测和缺陷的准确定性。并分析了焊缝中裂纹产生在焊接性能良好的20钢根部的机理,其原因是D6A与20钢的厚度和抗拉强度差异太大,导致在焊接应力和拉伸应力的作用下,在20钢焊缝根部区域沿熔合线方向产生焊接裂纹。根据分析结果,改进焊接工艺后,裂纹得到了有效的控制。

Abstract:

To evaluate the welding quality of the dissimilar metals of D6A and 20 steels by robot automatic welding with X-ray test,the testing processes were arranged reasonably according to the welding structure,and high quality testing on the elliptic multil-layer welds and accurate characteration of flaws were achieved by elimating disturbance of weld appearance.The formation mechanism of cracks at the root of 20 steel with good weldability was analyzed.It can be attributed to great difference of thickness and tensile strength between the two kinds of steels,which leads to the cracks along bond line at the root of 20 steel by welding stress and tensile stress.According to the analyzed results,welding procedure was improved and cracks were restrained effectively.