Effect of laser surface remelting of 304 stainless steel

To study the effect of laser surface remelting (LSR) on the organization and properties of a 304 stainless steel surface layer, the microscopic morphology, hardness, roughness, adhesion, and corrosion resistance of the remelted layer (RL) are examined by changing the laser scanning speed (LSS). The experimental results show that the LSR technique hardens the 304 stainless steel substrate surface with a substrate hardness of 185 HV, and the maximum hardness after remelting is 248.9 HV. With an increase in the LSS, the surface roughness gradually decreases, while the bonding force first increases and then decreases, with the maximum bonding force being 26.1 N. At the LSS of 20 mm/s, the phase distribution in the RL is more uniform. The maximum self-corrosion potential of the RL reaches -0.718V, and the self-corrosion current density is 3.872 A/cm$^2$. The surface properties of 304 stainless steel are improved by using LSR.