Assessment of Fatigue Strength in Small-Specimen of AISI 3140 Steel

The fatigue strength on small-specimen of mild steel material subjected to rotating bending load has been investigated. Specimen materials were used AISI 3140 steel. The tests were carried out the specimen diameter of 2 and 1 mm at laboratory air. The results obtained can be summarized that fatigue strength of diameter 2 mm was higher than that of diameter 8 and 1 mm for AISI 3140 steel material. Assessment of fatigue strength in small-specimen of carbon steel material has been done based on experimental and the cross-sectional analysis. Fatigue strength of AISI 3140 steel was lower than that of SS400 and S45C steels. The size effect concentration were determined the ratio of fatigue strength small-specimen to the normative specimen. The cross-sectional A was decrease with increasing coefficient of cross-section size. These results were significant impact of the size effect on fatigue strength on metal materials.