Fatigue Strength of Steels Coated with Aluminum

• Published in: Journal of the Metal Finishing Society of Japan Vol. 23; no. 9; pp. 514 - 520
• Main Authors: SAGA, Takuro, TOBE, Shogo, MIYAGAWA, Ohmi
• Format: Journal Article
• Language: Japanese
• Published: The Surface Finishing Society of Japan 1972
• ISSN: 0026-0614; 1884-3395
• DOI: 10.4139/sfj1950.23.514

Fatigue tests under rotary bending were performed on specimens of 0.15 and 0.48% carbon steels and high chromium steels coated with aluminum. The effects of surface roughness of specimens before coating, slight notch, and annealing after coating on the fatigue strength were studied. The results obtained were as follows: (1) In the steels coated with aluminum by hot dipping, which have alloy layer thicker than about 80μ, the fatigue strength of rough finished (before coating) specimens (Hmax was about 30μ) was nearly equal to that of fine finished (before coating) specimens (Hmax was less than 1μ). (2) The fatigue strength of notched specimens generally increased by coating with aluminum by hot dipping. The increasing rate of the fatigue strength due to the coating increased with the decrease in the notch sensitivity index of base alloy: η=(β-1)/(α-1). The decrease in fatigue strength could be inhibited by annealing in austenitic region for a short time (less than 30min.) and the subsequent furnace cooling.