Effects of Laser Welding Parameters on Polarization Resistance Of AISI 321 Austenitic Stainless Steel

Abstract

Laser welding is one of the important welding methods with extensive applications in aerospace and automotive industries due to high quality and welding speed. On the other hand, the polarization resistance of welded parts is one of the quality criteria affected by welding parameters. In welded parts, the polarization resistance will be decreased due to some changes in the microstructure and residual stresses. In this study, the effects of different welding parameters on the polarization resistance of AISI 321 were investigated. At first, response surface methodology was used for design of experiments and three input parameters of laser voltage, pulsed laser frequency and the speed of table motion were defined. Nd: YAG laser was used to weld AISI 321 at different conditions. Then, the corrosion test samples were prepared and the polarization resistance of the samples were measured based on open circuit potential and electrochemical impedance spectroscopy. The effects of welding parameters were determined through experimental results obtained during the study. By increasing welding speed and decreasing laser voltage and laser frequency, the polarization resistance decreased. The obtained results could be used in optimization and adjustment of laser welding conditions to prevent the polarization resistance loss of AISI 321.