采用不同比例的氮气/氩气混合保护气，对2 mm厚的SUS301L奥氏体不锈钢进行了CO₂激光焊接试验，研究了不同比例氮气保护条件下焊缝的显微组织、综合力学性能和表面耐腐蚀性能。试验结果表明,在不同比例氮气保护条件下，均可得到微观组织形貌无明显差异的焊接接头，焊缝的氮含量基本与母材一致，焊缝中的相均由γ奥氏体和少量δ铁素体组成；接头抗拉强度、弯曲性能及显微硬度与母材相当；纯氩气保护下焊缝的耐腐蚀性能最好。随着保护气中氮含量的增加，焊缝表面的耐腐蚀性能逐渐降低，但腐蚀速率呈减缓趋势。

With different proportions of nitrogen-argon hybrid shielding gas, the experiment of CO₂ laser welding of 2 mm thick SUS301L austenite stainless steel is conducted. The microstructure, comprehensive mechanical, and surface corrosion-resistance properties under different proportions of nitrogen shielding gases are investigated. Experimental results indicated that, under different proportions of nitrogen shielding gases, the micro-morphologies of weld joints have no obvious difference, the nitrogen contents are the same as that of steel substrate, and the phase components are all γ-austenite with combination of a small amount of δ-ferrite; the tensile strength, bend strength, and micro-hardness of weld joints are comparable with that of steel substrate; the weld joint under the shielding of Ar gas possesses the best corrosion resistance property; with the increment of nitrogen content in shielding gas, corrosion resistance of weld joint surface gradually decreases, but the corrosion rate shows a lowering trend.