激光冲击处理对X70管线钢焊接接头力学性能的影响

摘要

利用激光冲击波对X70管线钢焊接接头进行了表面强化处理,分析了激光冲击强化处理后焊接接头组织结构,用显微硬度计测试了焊接接头显微硬度,通过X射线应力仪测定了残余应力沿焊接接头表面的分布规律,并对管线钢焊接接头激光冲击强化的微观机理进行了分析。结果表明：激光冲击波可以在焊接接头表面形成塑性变形层,显微硬度明显提高;材料组织均匀性得到了明显改善;消除了焊接接头表面残余拉应力,形成了残余压应力场。%The surface of weld joint of X70 steel pipeline was processed with Laser Shock Processing（LSP）.The structure of the weld joint after LSP was analyzed,and its micro-hardness was measured with micro-hardness tester,the distribution of the surface residual stress of the weld joint was measured with X-Ray Diffraction（XRD） method.The micro strengthening mechanism of the weld joint of X70 steel pipeline by LSP was analyzed.Results show that a plastic-deforming layer is formed on the surface of weld joint by laser shock wave,and the micro-hardness of weld joint obviously increases.The uniformity of material structure is significantly improved.The tensile residual stress on the surface of weld joint is eliminated,and a compressive residual stress field is formed.