Improvement in corrosion resistance of AISI 316L stainless steel weld cladding using GTA remelting technique

Abstract

The present work was focused on studying the influence of gas tungsten arc (GTA) remelting on metallurgical and intergranular corrosion behavior of AISI 316L stainless steel (SS) cladding fabricated using gas metal arc welding (GMAW) process. The microstructure of the clads was examined using optical microscopy. Vickers microhardness testing method was used to measure the microhardness of the clad in the as-deposited (using GMAW process) and GTA-remelted conditions. Intergranular corrosion (IGC) behavior of the clads was evaluated using the double loop electrochemical potentiokinetic reactivation (DLEPR) technique. The results showed that when AISI 316L SS clad was subjected to GTA remelting, there was a noticeable modification of its microstructure, as a consequence of which, an increase in microhardness was observed in the GTA-remelted clad. Furthermore, DLEPR tests showed that the GTA-remelted clad layer possessed a relatively lower degree of sensitization (DOS), and thus higher corrosion resistance compared to the GMA-deposited clad layer. In general, this work shows that GTA remelting can prove to be a cost-effective alternative for improving the surface properties of austenitic SS cladded components used for critical applications.