Effect of shot peening parameters on the surface integrity of 316L material

Abstract

Shot Peening (SP) is one of the frontier surface enhancement technology, it aids in assuring satisfactory fatigue life and reliability of in the marine and automotive components. To keep pace with the competitive globalisation market, it is benedictory to the SP industries in the improvement in applying statistical experimental technique in the investigations instead of using usual scientific method. In this paper, full factorial 2k Design of Experiment (DOE) technique was used to analyse surface roughness, microhardness and fatigue performance, on the specimens made of low carbon steel 316L material, using air blast type SP machine. This investigation examines the interaction effects of influencing parameters such as pressure, shot size, standoff distance and the exposure time at their two different levels. After going through confirmation test the analysis reveals the right combination of the parameters for better process control. In the aspect of surface integrity, the distribution of the microhardness beneath the surface in the direction of the peening is carried out. With the aid of contour plot fatigue life was analysed with respect to the surface hardness and roughness. Analysis of Variance (ANOVA) was also carried out to find out the significant peening parameters. This technique, which is having more commercial usage, will reduce the most effective domains such as cost and time, in the industries.