Abstract
The shot peening process is a widely used surface treatment method for improving fatigue strength and anti-wear characteristics. The surface of the material receives a so-called peening effect where strong local deformation forms a work-hardened layer or causes compressive residual stress. In the present study, the effect of peening time on surface hardness of spring steel was investigated. The optimum conditions were evaluated in an experiment using the conventional shot peening machine with shots of an average size. The projective method of the shot media was of the centrifugal peening type. The shot media of 1.0 mm diameter was high-carbon cast steel, and the workpiece used was the commercially spring steel JIS-SUP10. It was found from the present experiment that the optimum peening time for the conventional shot peening was about 90 s.
