Abstract
Object of the study: Durability in practice was investigated on various steels, which had been subjected to the nitriding treatment. Experiments were conducted to examine fatigue strength and wear resistance of the said steels. However, it was observed that the characteristics of residual stresses remained on the nitrided zone had remarkable effects on the durability. In these experiments, the residual stresses were measured with X-ray by applying the method of sin2φ to obtain the relation between the durability and the stresses.
Content of the study:
(i) As the results of fatigue tests, the highest durability of the various steels was observed at a nitrided hardness a little lower than the maximum.
(ii) Dry and lubricated sliding friction tests were conducted to examine wear resistance. The results showed that the highest wear resistance of the various steels was observed at the maximum nitrided hardness by selecting the conditions of nitriding treatment.
(iii) As the results of measuring the stresses with X-ray, it was observed that compressive stresses remained on the nitrided surface of the steels. Moreover, it was also confirmed that these stresses were very stable and had good effects on both of fatigue strength and wear resistance.
