氮气保护不锈钢激光焊接接头组织及力学性能  

Microstructure and Mechanical Property of Joints in Laser Welding of Stainless Steels with Nitrogen Shielding Gas

作　　者：李竹洁 吕俊霞[1] 邹江林[1] 张建超[1] 吴世凯[1] 

机构地区：[1]北京工业大学激光工程研究院,北京100124

出　　处：《中国激光》2016年第12期85-92,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(51505010)

摘　　要：采用不同比例的氮气/氩气混合保护气,对2mm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 COz 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 7-austenite with combination of a small amount of ^-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.

关 键 词：激光技术 激光焊接 氮气保护 奥氏体不锈钢 显微组织 缺口拉伸 耐蚀性能 

分 类 号：TG456.7[金属学及工艺—焊接]