Microstructural analysis and the influence of shot peening on stress corrosion cracking resistance of duplex stainless steel welded joints

摘要

This paper aims to study the weldment of duplex stainless steel (DSS) AISI 2205. Tungsten inert gas (TIG) welding is performed with controlled welding parameters. The effect of cooling rate on microstructural changes is analyzed by varying the heat input during welding. The results show that high heat input and excessive nickel content in the filler wire, leads to excessive formation of austenite phases in the fusion zone. Lower heat input nucleates lesser amount of austenite phases and also very low heat input causes lack of fusion in the weld joints. Microstructural variations due to welding are assessed by conducting the micro hardness test, impact toughness test and tensile test. To study the effect of shot peening, the samples are prepared from the DSS welded plate. The chloride induced stress corrosion cracking (SCC) test is conducted and the result shows a noticeable improvement in the corrosion resistance of the weld zone due to shot peening. The findings of this study can be used in marine applications.