Optimization of Process Parameters of Shot Peening for AISI 4340 Steel

Abstract

Surface modification is one of the important requirements of various components used in industrial applications. Shot peening is one of the surface modification techniques which is being widely used in automotive industry to enhance fatigue life and surface characterises of mechanical parts. In this thesis, the development of experimental set up for shot peening has been undertaken to investigate the effect of prominent process parameter on surface characterises of a given target surface. The major objective of this work is to investigate the effect of three prominent process parameters, namely Air pressure, Temperature of target surface and Stand-off distance on surface characteristics of AISI 4340 steel. The work material has been chosen keeping in view its applications in local industry related to automotive components. The performance of peening process has been measured in terms of surface hardness, surface roughness and residual stresses. An experimental design approach Response Surface Method (RSM) has been used for the design and analysis of experimental data. The effect of process parameters on performance characteristics has been depicted with the help of ANOVA. Optimal set of process parameters has been obtained on the basis of desirability approach. The optimised combination for best performance came as (Air pressure – 4.83 bars, Temperature of target surface – 30°C and stand-off distance-178 mm).