Multivariable Statistical Analysis of the Pulsed Laser Welding of UNS S32750 Super Duplex Stainless Steel (SDSS)
S. Saravanan, N. Sivagurumanikandan and K. Raghukandan
This study attempts to develop statistical model for predicting the tensile strength of Nd:YAG laser butt welded UNS S32750 super duplex stainless steel (SDSS) joints. Experimental design based on the central composite face centred design is attempted by varying the process parameters viz. laser power, welding speed and pulse frequency. Weld microstructure exhibit a smooth interface free from defects. Tensile strengths of the resulting welds are determined, as per relevant standard, for each experimental condition. The determined strengths are utilized to develop predictive models by employing response surface methodology (RSM). Analysis of variance determines the factors viz. welding speed and laser power are more influential in dictating the tensile strengths of the weld joints. In addition, the percentage error between the experimental and the predicted models is less than 2%.
Keywords: Nd:YAG laser, super duplex stainless steel (SDSS), laser welding, tensile strength, microstructure, statistical model, analysis of variance (ANOVA), response surface methodology (RSM)