微粒子ショットピーニングがオーステンパ処理球状黒鉛鋳鉄の面圧強さに及ぼす影響

抄録

For Austempered Ductile Iron (ADI) gears, a shot-peening is utilized to improve the bending fatigue strength. However, under some shot-peening conditions, the increase of surface roughness by shot-peening may deteriorate the surface durability of ADI gear. The authors in this paper investigate the influence of the fine particle shot-peening on surface durability of ADI (austempering temperature 375°C) roller using a disk machine with rolling and sliding. The results are summarized as follows : (i) After the fine particle shot-peening, the hardness and compressive residual stress near the surface are risen. Furthermore, the surface roughness is smaller than that after the conventional shot-peening. (ii) The surface durability of ADI roller with the fine particle shot-peening is superior to that of ADI roller with the conventional shot-peening. Consequently, if a shot-peening is applied to improve the bending fatigue strength of ADI gear, the fine particle shot-peening is available to prevent the deterioration of the surface durability.