WEAR RESISTANCE IMPROVEMENT OF 41CR4 STEEL ALLOY BY LASER SURFACE HARDENING

Abstract

In this paper an overview is given about laser surface modification process, which is developed especially with the aim of wear resistance improvement. Pulsed Laser was applied to 41Cr4 steel alloy specimens using a Nd: glass laser. Laser processing parameters examined in the present study included power density (3*10^5 to 9.5*10^5 W/cm²). The power density and interaction distance was chosen such that the maximum temperature approaches the melting temperature. The importance of sufficiently high temperatures has already been recognized to reduce the wear rate at the highest power density. The 41Cr4 steel alloy samples were examined using optical microscopic inspection, microhardness test to determine the metallurgical phases and pin-on disc machine was used to estimate wear resistance. It was found in this study the microstructure were relatively dependent of laser power density. However, the laser power density had a significant effect on structural and mechanical properties especially wear resistance in a given power density level.