钨极惰性气体保护焊过程中建筑钢冷裂纹形成机理研究

Study on Formation Mechanism of Cold Crack for Building Steel in Tungsten Inert Gas Welding Process

以中碳调质钢30CrMnSi作为研究对象,利用扫描电子显微镜观察分析冷裂纹的断口形貌,并利用断口形貌分析研究焊缝出现冷裂纹的原因。结果表明,30CrMnSi中碳调质钢焊缝引弧位置和中间端的裂纹断口形貌都是混合型的断口,近表面部分的热裂纹和微裂纹是潜在的冷裂纹裂纹源。

Taking medium carbon quenched and tempered steel 30CrMnSi as research subject, the fracture morphology of cold crack was observed using scanning electron microscopy; and the reasons of cold cracking in weld joint were analyzed by fracture morphology analysis. The results show that the crack fracture morphology of medium carbon quenched and tempered steel 30CrMnSi in weld arc position and middle position are mixed fracture, the thermal crack and micro crack are the potential cold crack source.