転がり疲れに及ぼす粗さ組合せとなじみの影響 : Hυ≒450のSCM440焼入れ焼戻し材の場合

抄録

Using hardened and tempered SCM440 alloy steel rollers with a hardness of about 450Hυ, the authors examined the effect of roughness combination of mating two surfaces on the occurrence of pitting under nearly pure rolling or rolling with sliding conditions. The present results showed a similar manner to the previous results obtained using thefmal refined S45C carbon steel rollers of about 320Hυ, but the roughness effects appeared more distinctly owing to the higher hardness and a decline in the running-in ability of the material. Namely, it was shown clearly that pitting is apt to occur on the smoother surface but is restrained on the mating rougher surface when two rollers with a large difference in the roughness are combined. Consequently the pitting life became very short when the faster side roller was rough and the slower side roller was smooth, while the life was extremely long when the roughness combination was reversed in rolling with sliding conditions. And it was supposed that such a distinctive feature in the occurrence of pitting is attributed to the difference in the plastic deformation due to the asperity interactions in the process of running-in.