Laser Welding and Post-weld Aging Treatment of a Fe-Cr-Ni-Mo-Ti-Cu stainless Maraging Steel
M. Yu, F-Y. Meng and J. An
The effect of welding speed and the response to post-weld aging treatment of Fe-Cr-Ni-Mo–Ti-Cu stainless maraging steel laser weldments have been investigated. Laser welding was carried out at a welding speed range of 1.0 to 3.0 m/min, and then post-weld aging was performed at a temperature range of 420 to 580°C. The welding speed ranging from 2.0 m/min to 3.0 m/min was suitable for laser welding of the studied maraging steel sheet. Hardness survey across the aged weldments revealed that hardness peaks in different zones after aging treatments occurred at different temperatures: 420°C for parent metal zone (PMZ), 460°C for the heat affected zone (HAZ) and 500°C for fusion zone (FZ). Hardness became higher in HAZ and FZ than in PMZ above 420°C and so the tensile failure location occurred in PMZ above aging temperature of 420°C. Among the applied aging treatments, aging at 460°C achieved the highest tensile strength of laser weldments.
Keywords: CO2 laser, laser welding, stainless steel, maraging steel, post-weld treatment, microstructure, hardness, tensile properties