Welded joints of dissimilar metals are often required in nuclear and chemical industries. Among the various types of material combinations, welded joint of austenitic stainless steel and martensitic stainless steel is one good option. Due to differences in mechanical, metallurgical and corrosion properties between the two dissimilar materials, selections of suitable welding parameters, filler materials, shielding gas mixture etc. are extremely important in order to avoid drastic thermal gradient, hence significant welding distortions. In the present work, defect free TIG welding of dissimilar materials AISI 304 and AISI 420 has been made successfully. Quality of the welded joint has been judged through tensile test, microstructural investigation, micro-hardness measurement, SEM fractography and XRD analysis. Corrosion behaviour of the welded joint at different concentrations of NaCl has been measured through potentio-dynamic polarization. Weldment shows passivity at different solutions.

中文翻译：

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TIG焊接奥氏体不锈钢AISI 304和马氏体不锈钢AISI 420的腐蚀行为

核工业和化学工业通常需要使用异种金属的焊接接头。在各种类型的材料组合中，奥氏体不锈钢和马氏体不锈钢的焊接接头是一种很好的选择。由于两种不同材料之间在机械，冶金和腐蚀性能方面的差异，选择合适的焊接参数，填充材料，保护气体混合物等对于避免剧烈的热梯度，从而显着的焊接变形至关重要。在当前的工作中，已经成功地完成了异种材料AISI 304和AISI 420的无缺陷TIG焊接。焊接接头的质量已通过拉伸试验，显微组织研究，显微硬度测量，SEM断层扫描和XRD分析进行了判断。通过电位-动力极化测量了焊接接头在不同浓度的氯化钠中的腐蚀行为。焊件在不同溶液中显示出钝性。