Experimental Design Approach to the Process Parameter Optimization for the Laser Lap Welding of Stainless Steel
J. Liu, H. Zhang and Y. Shi
This paper presents an experimental design approach to process parameter optimization for the laser lap welding of SUS301L austenitic stainless steels using Nd:YAG laser in order to reduce the welding deformations of the back of the welding seams while ensuring mechanical properties of welding joints. 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 maximization of resistance width and linear shearing strength. Laser power and welding speed in the range 3.61 to 3.69 kW and 7.59 to 7.88 m/min, respectively, with irradiation angles of 65 to 70º were identified as the optimal set of process parameters. However, the laser power and welding speed can be reduced to 3.50 to 3.51 kW and increased to 7.87 to 7.98 m/min, respectively, to obtain minimum distortion and better welds..
Keywords: Laser welding, stainless steel, lap welding, full factorial design (FFD), optimization, linear shearing strength, distortion