Abstract
Low cycle fatigue behaviors in Nb-bearing high strength, low alloy (HSLA) steel have been studied at plastic strain amplitudes Δε{lunate}p/2 ranging from 1 × 10-5 to 1 × 10-2 in air and in ultrahigh vacuum (UHV). Microcracks are initiated along slip lines both in air and in UHV, and grain boundaries act as effective barriers to the propagation of microcracks. Coffin-Manson relations are reasonably satisfied for the microcrack initiation life Ni and the fatigue life Nf both in air and in UHV. The accumulated total cyclic plastic strain energy Wi required for fatigue crack initiation and the accumulated total cyclic plastic strain energy Wf required for fatigue failure are expressed mathematically in the form of K(Δε{lunate}p/2)N. The computed values of Wi and Wf are in good agreement with the values determined experimentally. The vacuum environment enhances Ni, Nf, Wi and Wf. The environmental effect becomes greater as the plastic strain amplitude decreases.
Original language | English (US) |
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Pages (from-to) | 121-128 |
Number of pages | 8 |
Journal | Materials Science and Engineering A |
Volume | 186 |
Issue number | 1-2 |
DOIs | |
State | Published - Oct 15 1994 |
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering