Comparative Study of the Mechanical Property of AISI630 Stainless Steel Gas Tungsten Arc Welds with Different Filler Wires under Room and Cryogenic Temperature

This study investigates the microstructural evolution and tensile properties of AISI630 gas tungsten arc welded joints using similar composition and nickel-based alloy filler wire. The tensile properties of different samples were evaluated at both room temperature and cryogenic temperature (− 196 °C). After welding, the AISI630 + ER630 weld consists of lamellar martensite, while the AISI630 + SNi2061, AISI630 + SNi4060 and AISI630 + SNi6276 welds consist of a nickel-based face-centered cubic phase. The heat-affected zone of the solution-treated AISI630 gas tungsten arc welded joint consists of a δ-ferrite expansion zone, retransformed martensite zone and ε-Cu precipitate zone. The AISI630 + ER630 joint exhibits a ductile-to-brittle transition phenomenon when the tensile conditions switch from room temperature to − 196 °C. The AISI630 + SNi2061 and AISI630 + SNi6276 exhibit ductile fracturing processes both at room and cryogenic temperatures. The mechanical properties of the AISI630 + SNi4060 joint were deteriorated by solidification cracking.