硅含量对氩弧焊熔敷金属冲击韧度的影响

通过示波冲击、断口扫描及显微组织观察等试验,研究了小于0.5%的硅含量对低含氧量手工氩弧焊熔敷金属冲击韧度的影响。结果表明,随着硅含量的增加,熔敷金属冲击韧度下降;低硅含量时,熔敷金属显微组织以针状铁素体为主,高硅含量时,则以块状铁素体为主;低硅氩弧焊熔敷金属低温冲击断裂形貌以准解理为主,裂纹扩展功高于断裂形貌主要为解理的高硅含量熔敷金属;低氧氩弧焊熔敷金属中,硅含量、显微组织、断裂形貌与冲击韧度之间存在着对应关系。

Effect of Silicon Content on Impact Toughness of Argon Arc Welding Deposit

The effects of Si content(<0.5%)on impact toughness of argon arc welding deposit were studied by the instrumented impact test,SEM and mircostructure examination.The results show that the impact toughness of deposit decreases with the increase of Si content.The microstructure of deposit is mainly acicular ferrite when Si content is low,and block ferrite when Si content is high.The fracture surface of specimens with low Si content is mainly quasi-cleavage,and its crack propagation energy is better than the specimens with high Si content.The Si content,microstructure,fracture surface and impact tougness of the deposit with low oxygen content have correlationship.