采用钨极惰性气体保护焊工艺对2205双相不锈钢管进行焊接，研究了全程采用ER2209焊丝、根焊采用ER2594焊丝所得的焊接接头的化学成分、显微组织、力学性能和耐腐蚀性的差异。结果表明：与全程采用ER2209焊丝的焊接接头相比，根焊ER2594焊丝的焊接接头及其热影响区的铬含量提高了6%~10%，奥氏体相含量增多，两相组织分布更均匀，力学性能和耐应力腐蚀性能良好，腐蚀速率降低约95%，且根焊的耐腐蚀性比母材更优。因此，采用ER2594焊丝进行根焊，可有效地解决2205双相不锈钢焊缝耐腐蚀性较母材差的问题。

The 2205 duplex stainless steel pipe was welded by inert gas tungsten arc welding. The differences of chemical composition, microstructure, mechanical properties and corrosion resistance between the whole welding joint by ER2209 wire and the root welding joint by ER2594 wire were studied. The results show that compared with the whole welded joint by ER2209 welding wire, the chromium content in welded joint and heat affected zone of the root welding ER2594 welding wire was increased by 6%~10%, the austenite phase content was increased, the distribution of two-phase structure was more uniform, the mechanical properties and stress corrosion resistance were good, and the corrosion rate was reduced by about 95%, and the corrosion resistance of the root welding was better than the base metal. Therefore, using ER2594 wire for root welding could effectively solve the problem that the corrosion resistance of 2205 duplex stainless steel weld was worse than that of the base metal.