Purpose: The present work aims to investigate the influence of CO2 laser spot welding
(LSW) parameters on welding profile and mechanical properties of lap joint of AISI 321 thin
sheet metals, and analyze the welding profile numerically by finite element (FE) method.
Design/methodology/approach: The weld carried out using 150 W CO2 continues
wave laser system. The impact of exposure time and laser power on the welding profile
was investigated using an optical microscope. Microhardness and tensile strength tests
were used to evaluate the mechanical properties of the joint. Ansys software was utilized to
simulate the welding profile numerically.
Findings: The results revealed that 2 s exposure time and 50 W power have led to uniform
welding profile and highest shear force (340 N), lower hardness gradient across the heat
affected zone (HAZ) and fusion zone (FZ). Finite element (FE) analysis of the welding profile
showed good agreement with experimental analysis.
Research limitations/implications: The selection of laser spot welding parameters for
thin sheet metal was critical due to the probability of metal vaporisation with extra heat input
during welding.
Practical implications: Laser welding of AISI 321 steel is used in multiple industrial
sectors such as power plants, petroleum refinement stations, pharmaceutical industry, and
households. Thus, selecting the best welding parameters ensures high-quality joint.
Originality/value: The use of CO2 laser in continuous wave (CW) mode instead of pulse
mode for spot welding of thin sheet metal of AISI 321 austenitic stainless steel consider a
real challenge because of the difficulty of control the heat input via proper selection of the
welding parameters in order to not burn the processed target. Besides, the maintenance is
easier and operation cost is lower in continuous CO2 than pulse mode.