本文对30CrMnSiA钢制薄壁件采用微束等离子弧焊时减小冷裂纹和变形的原因,从零件表面的溫度场、焊缝和热影响区的大小、晶粒长大情况、硬度分布、焊后组织状态、焊接时产生的塑性变形量和焊后残余应力的分布以及接头的机械性能(σ_b、δ、弯曲角和拉伸疲劳寿命)等几个方面,与气焊、氢原子焊、氩弧焊做了对比。对微束等离子弧焊规范的影响也做了讨论。 In this paper, the reason of reducing the cold crack and the deformation of 30CrMnSiA thin-walled steel by micro-beam plasma arc welding is studied. From the temperature field of the part surface, the size of the weld and heat affected zone, the grain growth, the hardness distribution, And the mechanical state (σ b, δ, bending angle and tensile fatigue life) of the joint after welding, such as gas welding, hydrogen atom welding, argon arc welding Welding contrast. The effect of micro-plasma arc welding specifications is also discussed.