Activities of JSSR (Japan Society for Spring Research) and Recent Research on Materials and Design for Industrial Springs

摘要

The result of the artificial pit spring fatigue test indicated that, at the same pit depth, greater hardness causes the fatigue life to shorten. This result conforms to the corrosion fatigue test result given in the previous study of the relation between hardness and corrosion fatigue. When the pit depth is too shallow. Though, greater hardness causes the fatigue life to lengthen. This result is justified by the fact that, when the surface roughness of material decreases (i.e. Smoothed), the stress concentration decreases with the increased fatigue strength.