転がり疲れに及ぼす粗さ組合せとなじみの影響 : グリットブラストされた鋼製ローラの場合

抄録

Combining a grit-blasted steel roller and a ground steel roller with different hardnesses, 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. As the results, combined effects of surface roughness and hardness related to the severity of asperity contacts and the running-in ability were recognized. When there is a large difference in the hardness between two surfaces, the roughness of the harder surface plays a dominant role. Pitting hardly occurred in the combination of a grit-blasted rough surface and a very smooth hardened surface. In the case of almost the same hardness combination, the results showed similarities to the previous results obtained using cylin-drically ground steel rollers, but the roughness effects appeared more distinctly, owing to the surface topography peculiar to grit blasting (surface with many protrusions and dents), and a decline in the running-in ability. Namely, it was shown that pitting is apt to occur on the smoother surfaces 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 wad reversed in rolling with sliding conditions.