1Cr18Mn8Ni5N不锈钢熔焊接头组织和性能研究

Study on Microstructure and Properties of 1Cr18Mn8Ni5N Stainless Steel Welding Joints

采用光学显微镜、扫描电镜、电化学工作站等研究了1Cr18Mn8Ni5N不锈钢熔焊接头的显微组织、力学性能和耐腐蚀性能。结果表明:等离子弧焊(plasma arc welding,PAW)和TIG焊接头的焊缝区和熔合区组织均由铁素体和奥氏体组成。焊缝的铁素体呈骨架状和板条状,熔合区的铁素体为蠕虫状。热影响区组织为粗大的奥氏体。两种焊接接头均具有良好的力学性能,其中PAW接头比TIG接头具有更高的强度、塑性,其拉伸断口有大量细小的韧窝而呈现出更好的韧性。但PAW焊缝因含有较多的铁素体,其显微硬度略低于TIG焊。在3.5%Na Cl溶液中,PAW焊缝的耐腐蚀能力低于TIG焊缝。

The microstructure, mechanical properties and corrosion resistance of 1Crl8Mn8Ni5N stainless steel fusion welded joints were studied by using optical microscope, scanning electron microscope and electrochemical workstation. The results show that the microstructures of weld zone and fusion zone in PAW and TIG welded joints are composed of ferrite and austenite. The ferrite in the welds shows skeleton and lath shape, and the ferrite in fusion zone is wormlike. The microstructure of heat affected zone is coarse austenite. The two welded joints have good mechanical properties, and the PAW joints have higher strength and ductility than the TIG welded joints, and the PAW welded joints also have better toughness because of a large number of small dimples in fracture. However, the microhardness of PAW weld is lower than that of TIG joint due to massive ferrite in the weld. The corrosion resistance of PAW joint in 3.5% NaCl solution is lower than that of TIG weld.