Experimental design approach to the process parameter optimization for laser welding of martensitic stainless steels in a constrained overlap configuration

This paper presents an experimental design approach to process parameter optimization for the laser welding of martensitic AISI 416 and AISI 440FSe stainless steels in a constrained overlap configuration in which outer shell was 055 mm thick. To determine the optimal laser-welding parameters, a set of mathematical models were developed relating welding parameters to each of the weld characteristics These were validated both statistically and experimentally. The quality criteria set for the weld to determine optimal parameters were the minimization of weld width and the maximization of weld penetration depth, resistance length and shearing force. Laser power and welding speed in the range 855-930W and 4.50-4.65 m/min, respectively, with a fiber diameter of 300 pm were identified as the optimal set of process parameters However, the laser power and welding speed can be reduced to 800-840W and increased to 4.75-5.37 m/min, respectively, to obtain stronger and better welds.