22MnB5钢焊点的力学试验

对淬火后22MnB5钢点焊结构进行了试验分析。通过拉伸试验结合应变片测得超高强钢的弹性模量、泊松比和焊点周边的力学特性及硬度与金相的观察分析，通过光学显微镜分析焊点处的断口样貌，得到了点焊结构破坏的原因，初步确定超高强钢点焊结构由塑性环、焊核、母材三部分组成。焊点处的力学变化是复杂的，远力端首先破坏失效，并且显示出了受力方向，塑性环是硬度最小部位，拉伸作用后连接部分产生负弯矩，该变矩作用能使焊核产生很小的转动角度。

Mechanics Experiments for 22MnB5 Steel Solder-joints

For quenching steel of 22MnB5 spot welding structure was analyzed in test. Ultra-high strength steel elastic modulus，Poisson's ratio， the mechanics properties of solder joints surrounding and hardness，metallographic observation analysis were obtained through tensile test with the strain gauge measurements. The reasons for damage of the structure by spot welding were obtained by the optical microscope analyses of solder joints of fracture appearance, and the super-high strength steel solder structure consisted of the plastic ring， resistance spot welding and the base three parts preliminarily. The mechanics changes of solder joints are complex，far end forced may first damage failure， and shows the stress direction of the plastic ring is of smallest hardness，the connecting part produces negative bending moment after stretching，this bending may make the welding produces a small rotation angle.