Fatigue strength of ultra-fine grained steels

MIRCO DANIEL CHAPETTI; H MIYATA; TAGAWA, T; MIYATA, T

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

Elsevier Ltd.

Año: 2004 vol. A381 p. 331 - 336

0921-5093

Fatigue strength of two ultra-fine grained steels (grain sizes 0.8 mm and 1 mm) was investigated. A coarse grained (grain size 12.5 mm) SM490 steel with a similar chemical composition was also analysed for comparison purpose. An important improvement on smooth fatigue strength was observed in ultra-fine grained steels and results obey the Hall-Petch relation usually observed between smooth fatigue limit and grain size. High fatigue notch sensitivity was observed and no improvement in fatigue limit of sharp notches is expected