Laser Melt Processing of H13 Tool Steel

H13 has been widely used in hot and cold work tooling applications and the thermal processing of H13 has important industrial significance particularly where longer tool life is important. This paper presents some results of the CO2 laser assisted processing of H13 tool steel. A block of preheated H13 tool steel was laser processed at six different parameters. Laser power (P) and Scan speed (V) were chosen as the primary variables. The processed region was characterized for geometry, micro hardness and microstructure. The block temperature was monitored using an alumel-chromel thermocouple. Optical observations indicated that the aspect ratios of the processed zone increased with power. Microhardness observations indicate that higher cooling rate parameters had higher hardness values. Finer dendrites were visible at higher power values. These observations were corroborated by magnitude of thermal change predictions made using the Rosenthal equation