Dissimilar Welding of Inconel Alloys With Austenitic Stainless-Steel: A Review

Abstract

In this review paper, dissimilar welding between Inconel and austenitic stainless steel along with its application has been outlined for high-temperature applications. The mechanical and microstructural behavior of this dissimilar joint has been summarized thoroughly in this article. Dissimilar welding of Inconel alloys and stainless steel (SS) has massive demand in high temperature and high corrosive applications industries. Austenitic stainless steel contains 16–26% of Cr and 6–12% of Ni elements showing FCC structures have good weldability and high corrosion resistance. Austenitic stainless steel such as 304, 316 L, 304H, etc., containing austenite microstructure used in high-temperature applications like power plants, heat exchangers, heating elements, aircraft, and others. In addition, Ni-based Inconel alloys show high-temperature strength and corrosion resistance and are frequently used in high-temperature applications. Ni-based Inconel 718 alloy possesses excellent strength, corrosion resistance and creep resistance at high temperatures are frequently used in combustion chambers, power plants, and turbine blades applications. Inconel alloyed by elements Ti, Al and Nb attain strength by forming phases such as ɣ/-Ni3(-Ti, Al), ɣ//-Ni3Nb, and carbides such as MC and M23C6, nitrides, laves phase. The GTA dissimilar welding between expensive Inconel and cheaper stainless steel is successfully used in nuclear power plants. The dissimilarity in melting point, chemical composition, thermal, mechanical, and other properties between these materials make welding challengeable. This review paper focused on problems related to dissimilar welding like forming unmixed zone, elemental segregation, formation of laves phase, sensitization, microfissuring, and solidification cracking.