Laser Surface Hardening of ASTM A516 Medium Carbon Steel using Nd: YAG Laser

Abstract

In order to improve the tribological properties and also to increase the service life of components
laser surface hardening (LSH) is an effective technique. In recent years LSH has been
able to compete with traditional surface treatment processes particularly in terms of cost.
For localised hardening of materials Nd: YAG lasers and CO2 lasers are most widely used.
The present study reports the hardening characteristic of ASTM A516 medium carbon steel in
a LSH process using continuous wave Nd: YAG laser. Uniform beam technique is used for
laser hardening. The micro-structural features occurring in laser hardened A516 are discussed
with the use of optical microscope. The effect of process parameters on the depth and
hardness of laser treated surface are investigated. In optimum process parameters maximum
hardness (214 HV) in the laser surface treated area is achieved. The effect of LSH on wear
resistance is described. Wear resistance of laser surface hardened sample evaluated by using
reciprocating type equipment shows marginal improvement as compared to base metal.