Continuous wave diode pumped Nd:YAG laser was applied to weld AISI 316L Stainless
steel. Butt joint sheets of 1.5 mm thickness and 30 mm width were joined together in a single
pass without using filler material. Design of experiment is applied to investigate the effects of
laser power and welding speed on penetration depth and mechanical properties (tensile
strength and microhardness). The depth of penetration is directly proportional to the laser
power and inversely proportional with the welding speed. Maximum penetration depth was
753 μm. The tensile strength is directly proportional with the laser power. Maximum tensile
strength is 632 MPa. Ductile fracture is revealed by SEM analysis. The average value of
microhardness of the weld is 275 HV while the average of the base metal reached 225 HV,
this is because of the presence of different phases in weld metal from base metal.