Rotating bending fatigue tests were carried out for Inconel 718 at room temperature to investigate the growth characteristics of a small crack. It was found that: (1) The crack initiated at the grain boundary and then propagated as a transgranular crack. (2) When the stress level was higher than the fatigue limit, the fatigue life was mainly controlled by the growth life of a crack smaller than 1 mm. (3) The fatigue limit was a limiting stress for the crack propagation. (4) At low stress levels (σa/σ0.2<0.5, σa: stress amplitude, (σ0.2:0.2% proof stress), the crack growth rate was determined by the stress intensity factor range ΔK; and at high stress levels (σa/σ0.2>0.6), it was determined by the small crack growth law.
|Number of pages||5|
|Journal||Nippon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A|
|Publication status||Published - Jan 1 1997|
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering