ER70S-6焊丝拉拔断裂原因

Reasons for drawing fracture of ER70S-6 welding wire

某ER70S-6气体保护焊丝发生拉拔断裂现象,采用宏观观察、化学成分分析、金相检验、扫描电镜分析等方法对ER70S-6拉拔断裂焊丝进行分析。结果表明:在冷拉过程中,拉丝工艺参数设置不完善导致在拉丝过程中温度达到相变温度,组织中形成过渡态贝氏体,材料在变形过程中发生加工硬化现象,使得材料整体脆性大大增加;材料心部存在一定程度的偏析,首先萌生多断裂触发点,在连续拉拔过程中,材料发生断裂现象。

The drawing fracture phenomenon of ER70S-6 gas shielded welding wire was analyzed by means of macroscopic observation,chemical composition analysis,metallographic examination and scanning electron microscope analysis.The results show that during the cold drawing process,the imperfect setting of the drawing process parameters led to the temperature reaching the phase transition temperature during the drawing process,and the transition bainite was formed in the structure.The work hardening of the material occured during the deformation process,which greatly increased the overall brittleness of the material.There was a certain degree of segregation in the core of the material.First,multiple fracture trigger points were initiated.During the continuous drawing process,the material cracked.