OPTIMIZING THE LASER PARAMETERS TO ATTAIN THE MAXIMUM HARDNESS IN COBALT BASED (STELLITE - 6) HARDFACED SURFACES

Abstract

Laser Hardfacing are naited mainly to improve the service life of engineering components either rebuilding or
fabricating in such a way to produce a composite wall section to wear, erosion, corrosion, etc. The main characteristics of
CO2 laser hardfaced surfaces are good metallurgical bonding, low heat input and less dilution. In this paper, a provare has
been made to optimize the process parameters of laser hardfaced surfaces such as Laser Power(P), Travel Speed(T),
Defocusing Distance(D) and Powder feed rate(F).The optimization of laser hardfaced surfaces have good product
development, value annexation, revive and restoration. The laser hardfacing is carried out by CO2laser by coaxial - powder
feeding method. Inthis hardfacing process AISI 304 stainless steel is used as the base metal and the cobalt basedStellite 6
powder is used as hardfaced material. The influence of theprocessing variables on hardness is bespeaked for optimized
condition. The experiments were conducted based ona four factor and five level central composite rotatable design. The
mathematical model wasdeveloped using Response Surface Methodology(RSM) technique to predict the hardness. The
interaction effects of input processparameters of laser hardfacing were discussed. The optimized process parameter for laser
hardfacing and the influenced parameterwere identified.