座式点焊机机械特性对高强钢点焊工艺的影响

Effect of mechanical characteristics of pedestal spot welding machines on the joining of high-strength steel

为了研究座式点焊机机械特性对焊接工艺性能的影响,测试了4种不同型号气动加载点焊机摩擦力、低合金高强钢B340LA的可焊电流范围、2台焊机点焊过程中的压力和位移变化曲线。结果表明,不同的点焊机有不同的摩擦力范围,而且差异显著。分析认为这种差异是导致不同焊机点焊工艺性能差异的主要原因之一,加载系统摩擦力小的焊机可焊电流范围大;点焊接头的剪切强度由焊点熔核直径决定,熔核直径相等焊点的剪切强度基本相等,每一种焊机都可在一定焊接电流范围内得到符合规范要求的熔核直径。

Pedestal spot welding machines are widely used in sheet welding. In order to study the effect of the mechanical properties of pedestal spot welding machines, we tested the friction of four different spot welding machines and the welding current ranges for high strength low alloy steel B340LA. The pressure and displacement signals of 2 spot welding machines during welding were also recorded. The results show that different spot welding machines differ greatly in the range of friction, which is one of the main reasons for the difference in spot welding performance. A welding machine with smaller friction can enlarge the welding lobe. The results also show that the weld shear tension strength is determined by the nugget diameter of the welding spot. Welding spots with equal nugget diameters will have similar shear tension strengths. Each welding machine is able to produce welding spots of required nugget diameter within a certain welding current range.