采用窄间隙全固态光纤激光填充热丝焊接方法取代了以往的窄间隙非熔化极气体保护焊(TIG)填充热丝焊接方法,焊接板厚为20mm、材质为SUS304奥氏体不锈钢。初步确定适合于窄间隙激光填充热丝焊接的坡口形式和焊接工艺参数;通过试验,研究分析焊缝金属组织中气孔和结晶裂纹产生的原因;调整工艺参数,在优化后的最佳工艺参数下,获得了热影响区域小、表面成形性好、无焊接缺陷的焊接接头;焊缝金属为细小的奥氏体柱状晶,与母材形成良好的连接;焊接变形小,满足了焊接变形要求;焊缝金属的显微硬度略高于母材,拉伸性能和弯曲性能均满足试验要求,获得了力学性能良好的焊接接头。 A narrow-gap all-solid-state fiber laser filled hot wire welding method is adopted instead of the conventional narrow gap non-melting gas shield (TIG) filled hot wire welding method. The welding plate thickness is 20mm and the material is SUS304 austenitic stainless steel. The groove form and welding process parameters suitable for laser welding of narrow gap laser are preliminarily determined. The causes of the pores and crystal cracks in the weld metal structure are analyzed and analyzed through experiments. The optimum process parameters , The welded joint with small heat affected zone, good surface formability and no welding defects was obtained. The weld metal was fine austenite columnar crystal, which formed a good connection with the base metal. The welding deformation was small and satisfied the welding deformation requirements The microhardness of the weld metal is slightly higher than that of the base metal, the tensile properties and the bending properties meet the test requirements, and the welded joints with good mechanical properties are obtained.