异种钢电阻塞焊飞溅缺陷的产生机理

Mechanism of spatter defects in resistance plug welding of dissimilar steel

文中采用电阻塞焊对等厚的异种钢板进行焊接,利用正交试验和极差法优化分析了影响飞溅缺陷的关键焊接参数,然后对接头进行冲击试验,从熔池形成、焊接时序、电阻分布规律、电极力、热量变化等方面研究了飞溅缺陷的产生机理.结果表明,发生飞溅的接头冲击吸收能量大大降低;电阻塞焊的接触电阻变化过程包括填充物受热、压平及熔核形核三个阶段,随着焊接过程的进行及填充物形状的变化,接触电阻呈增大—减小—再增大的趋势;在压平阶段填充物受热结束时瞬时热量突增是造成焊点外侧边缘飞溅的主要原因;在压平过程中两种钢接触面间隙太大是造成结合面飞溅的主要原因.

Resistance plug welding was used to weld dissimilar steels.Orthogonal test was used to optimize welding parameters and range method was used to analyze the key factors affecting spatter defects.Then impulse tests were carried out on all resistance plug welded joints.The formation of molten pool,the law of resistance distribution and the electrode were studied.The mechanism of spatter of resistance plug welding was studied in the aspects of pressure and heat change.The results showed that spatter has a great influence on the impact absorbing power of the resistance plug welding joint.The impact absorbing power of the spattered blocking welded joint is greatly reduced.The process of resistance plug welding includes filler heating,filler voltage leveling and nugget.In the three stages of nucleation,the contact resistance increases,decreases and increases again with the welding process and the change of filler shape;at the end of the flattening stage,the instantaneous heat surge is the main reason for the splash on the outer edge of the solder joint;and during the flattening process,the large gap between the two kinds of steel contact surface is the main reason for the splash on the joint surface.