316L stainless steel is one of the types of austenitic stainless steels that have very good corrosion resistance due to the presence of alloying elements such as chromium, nickel and molybdenum and the formation of a passive layer on their surface. This feature, together with high weldability, has made them a suitable option for various industrial applications such as oil, gas, petrochemical and medical. In this study, the Nd:YAG pulsed laser welding process was used to join two pieces of 316L stainless steel, and the effect of pulse time on the quality and hardness of the weld and corrosion resistance in a sulfuric acid environment was investigated. The results of corrosion analyses in this study showed that reducing the pulse time in the laser welding process has a significant effect on reducing the corrosion rate of the weld metal due to formation of equiaxed grains in the weld zone. When the pulse time is reduced from 8 ms to 4 ms, the heat input increases from 100 to 124 J/mm and solidification rate R and thermal gradient G and the G/R and G×R ratios decrease, which causes the grains to form more equiaxed and uniformly in the weld zone. This type of structure, due to the regular and dense arrangement of the grains, provides better mechanical properties and greater resistance to corrosive agents such as acids and salts. It causes the corrosion current to decrease from 520 nA/( cm^2 ) to 90 nA/( cm^2 ).