Microstructure and mechanical properties of similar and dissimilar metal gas tungsten constricted arc welds: Maraging steel to 13-8 Mo stainless steel

Abstract

Maraging steel (250) and 13-8 Mo stainless steel plates were joined by gas tungsten constricted arc welding (GTCAW) process in similar and dissimilar metal combinations using 13-8 Mo stainless steel filler wire. The similar and dissimilar metal welds made in solutionized condition were subjected to standard post weld hardening treatments direct ageing at 485 °C, soaking for 3½ hours followed by air cooling (ageing treatment of maraging steel) and direct ageing at 510 °C, soaking for 4 h followed by air cooling (ageing treatment of 13-8 Mo stainless steel). The joint characterization studies include microstructure examination, microhardness survey across the weldments and transverse weld tensile test. Similar and dissimilar metal weldments responded to both the post weld ageing treatment. After post weld aging, increase in yield strength, UTS and slight reduction in % elongation of similar and dissimilar metal were observed. The observed tensile properties were correlated with microstructure and hardness distribution across the welds. Keywords: Maraging steel (250), 13-8 Mo stainless steel, Mechanical properties, Microstructure