The influence of post weld Heat Treatment on Mechanical and Corrosion Properties of martensitic Stainless Steel after TIG

In this study, corrosion and mechanical properties of AISI 420 martensitic stainless steel after welding and heat treatment were studied. Heat treatment cycle in order to optimize the mechanical and corrosion properties of the steel after welding was investigated. After TIG welding and heat treatment of tempering, hardness and tensile, and impact mechanical tests and corrosion polarization tests were performed on the samples. Also to study the microstructure and identify the type of the happened corrosion, by optical microscopy and transmission electron microscopy (SEM), the samples were examined. By The results of mechanical tests and corrosion, heat treatment conditions to achieve optimum mechanical properties and good corrosion properties was determined after welding. In conclusion, the cycle of heat treatment of tempering at a temperature of 300˚C and 1 hour, is an appropriate cycle in order to achieve Suitable corrosion and mechanical properties for welded 420 stainless steel.