WELDABILITY OF AUSTENITIC HEAT-RESISTING STEELS

Abstract

Austenitic heat-resisting steels are used in a wide range of industries. Their use is motivated not only by their excellent mechanical properties but also due to their excellent resistance to corrosion and the ability to withstand high temperatures. These steels are prone to defects and challenges during welding because of their high content of Cr, Ni, Al, and other alloying elements. The main problem is the high heat energy input, which causes differences in structure between the welded joint and the surrounding area. The relatively high heat input and cooling in the heat-affected zone (HAZ) causes carbide formation and, as a result, coarse-grain formation, which is undesirable for obtaining favorable mechanical properties. This study investigates the weldability of two heat-resistant austenitic steels (EN X12CrNi23-13 and EN X8CrNi25-21) using the gas tungsten arc welding (GTAW) technique. Both materials are separately analyzed, and the results are discussed in terms of potential welding techniques and technological plan improvements to achieve high quality welds without pre-heating or any other additional post-welding heat treatment, which is important for the industry because it can reduce production time and cost.