Abstract
Using a two-disc machine scuffing conditions were investigated with a 0.45% carbon steel quenched which had high surface hardness and low ability to form oxide film compared with an annealed or a refined carbon steel reported in the previous papers. The following results were obtained. (1) It was confirmed that there were three critical surface temperatures with respect to incipient scuffing. In order to prevent scuffing at each critical temperature the film parameter must be kept above a certain value according to the operating condition represented by the product of the load and the sliding speed. (2) When the film parameter became below unity, the formation of oxide film effective in decreasing the coefficient of friction and enhancing the scuffing resistance was promoted unless scuffing took place. (3) The rotational ratio of a high speed disc to the mating low speed disc, integral or hunting, also affected EHL film formation and scuffing resistance.
