Damage to Metallic Materials- Study project on techniques and early detection of SCC in stainless steels Type 304L Control of initiation and propagation of SCC cracks

Abstract

This thesis proposes to establish an empirical study between the microstructure and the electrochemical and mechanical behavior of welded joints in austenitic stainless steels AISI304L as well as the early detection of SCCs and the control of the initiation and propagation of SCC cracks. This work is a continuation of research carried out in the field of improving the resistance of pipelines to corrosion. It aims to identify the welding parameters of 304l steel by electric arc (TIG) on the corrosion of welded joints in particular in the HAZ. To do this, welded samples were taken with different parameters on which mechanical and electrochemical tests were carried out to demonstrate the behavior of this zone in a corrosive environment similar to seawater (30 g / l). Using an experimental design based on the FED method, we estimated the contribution of the experimental factors (welding parameters) :( Number of passes, argon gas flow rate and the welding current) as well as the microstructure through the welded joint on corrosion behavior. The comparative study between welding joints due to their corrosion resistance shows better resistance to stress corrosion of AISI 304L.