Effect of activator on mechanical properties and intercrystalline corrosion resistance of austenitic stainless steel weld

摘要

5 mm thick austenitic stainless steel was welded using an A-TIG welding process with in-house developed activators. The microstructure, mechanical properties, and intergranular corrosion resistance of the weld joint were characterized. The microstructure of conventional TIG and A-TIG welds were all austenite with a small amount of delta-ferrite. The included angle between the fusion line and rolling direction of the conventional TIG and A-TIG welds were nearly 0 degrees and 90 degrees, respectively. The microstructure of the A-TIG weld had more and finer delta-ferrite under conditions of less heat input. Compared with the conventional TIG weld, the tensile strength of the A-TIG weld was enhanced approximately 10%, and the elongation was increased by 30%. The microhardness of the conventional TIG weld was found to be 280HV, and the microhardness of the A-TIG weld was 210HV. The corrosion rates of substrate, conventional TIG and A-TIG welds were measured and found to be 0.056 mm/h, 0.110 mm/h and 0.065 mm/h respectively. The chromic carbide content in the conventional TIG weld was higher than that of the A-TIG weld. (C) 2016 Elsevier B.V. All rights reserved.