INFLUENCE OF SHOT PEENING ON SURFACE CHARACTERISTICS OF HIGH-SPEED STEELS

High-speed steels are generally used for the cutting of other hard materials. These are hard materials, and can be used at high temperatures. Therefore, some of them are used for warm metal forming such as forging. However, in the tools used in hot working, an excellent hot hardness and long-life fatigue are strongly required. In the present study, the influence of shot peening on the surface characteristics of high-speed steels was investigated. Shot peening imparts compressive residual stresses on the metal surface, thus improving the fatigue life of the machine parts. In the experiment, the shot peening treatment was performed using an air-type shot peening machine. The shots made of cemented carbide were used. The workpieces were two types, W-type and Mo-type alloys. Surface roughness, compressive residual stress, and hardness of the peened work-pieces were measured. It was found that shot peening using the hard shot media was effective in improving the surface characteristics of high-speed steels.