Laser surface melting: A suitable technique to repair damaged surfaces made in 14 Ni (200 grade) maraging steel

Abstract A high power solid Nd-YAG laser, operating in continuous mode, was used to re-melt the surface of a maraging steel, 14 Ni (200 grade), in different heat treatment conditions. Processing parameters were optimized for the employment of this technique as a repairing procedure of damaged surfaces to increase the useful life of tools made in maraging steels. Different zones can be found in laser-heated material. In addition, the absence of austenite reversion, consistent with the low nickel content of this steel, was found with the exception of a few very small pools of austenite found in a narrow layer in the heat-affected zone of samples corresponding to one of the studied heat treatment conditions of steel. Laser surface melting (LSM) combined with aging heat treatment causes a significant rise in the hardness (from 325 to more than 520 HV 0.1 ) and in the wear resistance of the surface layer (with a decrease in the volume of lost material from 0.52 mm 3 in the steel in the laser surface melted condition to 0.28 mm 3 in the steel in laser surface melted and finally peak age hardening condition).