To study the metallurgical and mechanical properties of SMAW dissimilar weld joints between AISI 1020 carbon steel and AISI 410 martensitic stainless steel using three distinct fillers

This study investigates the metallurgical and mechanical properties of dissimilar weld joints between AISI 1020 carbon steel and AISI 410 martensitic stainless steel, fabricated using three distinct filler metals: austenitic AWS 309L and AWS 316L, and martensitic AWS 410. The weldments were comprehensively evaluated through tensile testing, Charpy V-notch impact testing, microhardness profiling, and microstructural analysis to determine the optimal consumable for this application. The results demonstrated the superior performance of the AWS 309L filler, which yielded the highest ultimate tensile strength (410.5 MPa) and greatest impact toughness (24.2 J). This enhanced performance was attributed to the formation of a desirable duplex microstructure of austenite and distributed delta ferrite in the fusion zone. Conversely, the weldment made with the matching AWS 410 filler, despite exhibiting the highest hardness (peak 532 HV), showed low impact toughness (18.7 J) and moderate tensile strength (371.3 MPa), indicating a brittle, untempered martensitic structure susceptible to failure. The AWS 316L filler produced the lowest mechanical properties overall. The findings conclude that AWS 309L is the most suitable filler metal, producing a robust and damage-tolerant joint, whereas the AWS 410 filler is inappropriate for this application in the as-welded condition due to its inherent brittleness.