Laser Hardening and Pack Boriding of EN 8D Steel

This work is composed of two different techniques, laser hardening using HPDL and conventional pack boriding of EN 8D steel to improve the mechanical properties. The α-Fe phase observed in the XRD pattern of untreated EN 8D transformed to martensite and cementite phases due to the effect of laser irradiation, which is evidenced from the microstructure analysis. The martensite phase in the laser hardened sample results in improved hardness with maximum of about 825 HV0.2. In case of pack boriding, the sample was packed with boriding agent and sealed in a stainless steel container at 950°C for 6 hours. XRD pattern reveals the Fe2B peaks, which confirms the formation of borided layer at the sample surface. The hardness value in the tooth like borided layer is increased from 261 HV to 1193 HV due to this Fe2B phase.