Corrosion and mechanical behaviour of TIG-welded AISI 304L stainless steel

Abstract

This study is an investigation into the effect of filler metal in Tungsten Inert Gases (TIG) welding of 304L austenitic stainless steel with 4 mm of thickness. Base materials were welded using double-sided single-pass TIG welding method, both with and without filler metal. There was a rigorous analysis for the welding properties, including microstructure, penetration, mechanical properties and corrosion behaviour. The microstructure investigation shows that ?-ferrite was formed in the austenite matrix in the welding metal for both joints. Penetration investigation indicates very high welding quality of both joints without obvious defect, such as cracks, lack of fusion, incomplete penetration and strips of defects. The tensile tests result for joints without filler metals have higher ultimate tensile strength, and they have greater elongation values. However, the yield strength is equal. After the salt spray tests, no corrosion was observed on the welding zones. Moreover, there is no loss of weight for all joints. As a result, it is possible for 4 mm thick AISI 304L stainless steels to be welded by double-sided single-pass TIG welding method, both with and without filler metal. © 2017 Scibulcom Ltd. All rights reserved.