Load Carrying Capacities of the Stainless Steel Gears with Multiple Coating Layr in Ultra-high Vacuum

采用四球机、双辊机和动力循环齿轮机研究了表面热扩散镀锡的不锈钢（SUS440C）球、滚子和齿轮在润滑脂润滑条件下的摩擦磨损特性。此外，齿轮试验在约10^<-4>Pa下进行。实验结果表明：在四球实验中，扩散层厚度约为6mum的球的抗癫痫能力是未处理球的2-4倍。处理和未处理球的临界表面温度平均值均为：未添加MoS_2的润滑脂为176C，添加3%的润滑脂为176℃，添加10%的润滑脂为191℃，添加30%的润滑脂为263℃。随着二硫化钼添加剂浓度的增加，油脂的临界扣押温度逐渐升高。在双辊试验中，有扩散层的辊的抗癫痫能力明显大于无扩散层的辊。随着二硫化钼添加剂浓度的增加，润滑脂的抗癫痫性降低。此外，处理后的轧辊的临界表面温度高于400℃。在滚子接触条件一致的情况下，临界表面温度的变化相对小于pV值的变化。在干摩擦条件下的齿轮试验中，处理后的齿轮在表面磨损破坏初期的运行时间明显长于未处理的齿轮。

The frictional and wear characteristics of the balls, the rollers and the gears of stainless steeel (SUS440C) of which the surface layr was thermally diffused after being Sn-plated were investigated by a four-ball machine, a two-roller machine and a power-circulating gear machine under grease lubrication.Further, the gear tests were carried out in the degree of about 10^<-4>Pa. From the tests, the following results were obtained :In the four-ball tests, the seizure resistance of the ball of which the diffused layr was approximately 6mum thick was 2-4 times larger than that of the untreated ball. With respect to the mean value of the critical surface temperature at seizure on both treated and untreated balls, it was 176C for the case of grease without MoS_2 additive, 176ﾟC with 3% additive, 191ﾟC with 10% additive, and 263ﾟC with 30% additive. The critical temperature at seizure was increasintg with increasing concentration of MoS_2 additive on grease.In the two-roller tests, the seizure resistance of the roller with the diffused layr was significantly larger than that without diffused layr. The seizure resistance was decreased with increasing concentration of MoS_2 additive on grease. Further, the critical surface temperature at seizure for the case of the treated roller was higher than 400ﾟC.The variation in the critical surface temperature was comparatively smaller than that in the pV value against the conformity of contacting condition on the rollers.In the gear tests under dry friction, the running time of the treated gears at the incipient stage of destructive surface failure by wear were significantly longer than that of the untreared gear.