【摘要】 为了解随焊冲击碾压法机理,用数值计算方法对冲击碾压轮引起薄壁结构焊缝金属塑性流变行为和应变场变化进行了分析。前轮对处于脆性温度区间的焊缝金属施加一个横向挤压塑性应变,减小甚至抵消致裂的拉伸应变,防止了焊接热裂纹的产生。后轮将焊缝金属的纵、横向压缩塑性变形充分碾展,减小了工件的残余变形和应力。实验结果证明随焊冲击碾压法能将平板薄壁试件纵向挠曲和横向收缩变形控制在常规焊接状态的1/10和1/5,残余应力值也明显降低;焊缝表面没有热裂纹,平整光滑。更多还原

【Abstract】 The plastic flow and the variation of the strain field in welds caused by impact rollers were analyzed numerically to study the effect of weld with trailing impact rolling (WTIR). The front impact roller causes transverse plastic compression strain in the weld which is in the brittle temperature range, which counteracts the tensile strain which leads to hot cracking. The rear impact roller stretches the weld longitudinally with transverse compressive plastic deformation of the weld, thus reducing the residual deformation and stresses in the bead. The experimental results show that the weld surface with WTIR is flat and smooth with no hot cracking in the weld. The longitudinal deflection deformation with WTIR is reduced by 90% while the transversal contraction deformation is reduced by 80% relative to an ordinary weld. The residual stresses in the weld are also greatly reduced.更多还原