摘要
使用不同直径的球面和平面电极进行铝合金试板的电阻点焊,对焊点进行外观检查、剥离试验、宏观金相等试验,研究电极端面形状、直径大小、表面状态对铝合金电阻点焊接头的影响。研究表明:电极的端面形态通过影响电极和母材的受力、电极-母材接触电阻、电流受流情况,从而影响电流热效应产生的热量,最终影响点焊接头质量。球面电极由于其球面特征,受力和受流情况优于平面电极,抗变形能力强,可连续点焊160点以上。电极直径影响电流受流情况和受力,较小的直径导致热量和受力集中,形成板间喷溅和熔核孔洞缺陷;较大的直径导致电流密度和压强小,无法形成熔核。粗糙表面增大了电极-母材接触电阻,产生热量过大,使母材表面过度烧损,形成缺陷。
Resistance spot welding of aluminum alloy test plates is carried out with spherical and planar electrodes of different diameters.Visual inspection,peeling test,and macroscopic metallographic test are performed on the welding points to investigate the influence of electrode tip shape,diameter,and surface condition on the resistance spot welding joints of aluminum alloy.Studies show that the morphology of electrode tip affects the stress between the electrode and the base material,contact resistance between the electrode and the base material,current flow and current collection,thereby influencing the heat resulted from the current heating effect and ultimately affecting the quality of spot-welding joints.Spherical electrodes,due to their spherical characteristics,have better stress and current collection conditions than planar electrodes,the former also has a strong deformation resistance,and can continuously weld more than 160 points.The electrode diameter affects the current flow and collection and the stress,a small diameter could lead to heat and force concentration,resulting in defects like interplate splashing and porous nugget;A large diameter results in lower current density and pressure,making it impossible to form a nugget.The rough surface increases the contact resistance between the electrode and the base material,generating excessive heat and causing excessive burning of the base material surface.
作者
裘彭军
赵峰宽
刘诚桓
QIU Pengjun;ZHAO Fengkuan;LIU Chenghuan(CRRC Qishuyan Institute Co.,Ltd.,Changzhou,Jiangsu 213011,China)
出处
《轨道交通材料》
2024年第5期25-27,32,共4页
Materials for Rail Transportation System
关键词
铝合金电阻点焊
球状电极
熔核直径
接触电阻
aluminum alloy resistance spot welding
sphere pole
nuclear diameter
contact resistance
