To examine the effects of the surface finish and defects on fatigue limit, specimens differently finished, i.e., sand paper(Grade #600, #80) finish and electrolytic polish, were prepared. Moreover, to simulate surface defects, a small artificial hole of which diameter is varied from 40 to 200 μm is introduced on the specimen surface. Both as-received and annealed specimens were applied so as to extract the effect of the work-hardened surface layer on the fatigue limit. Through examination of the fatigue limit and the non-propagating crack the following results are obtained: (1) The surface roughness slightly influences the fatigue limit, while the work-hardened surface layer has a primary effect on the fatigue limit. (2) An increase in the diameter of the small hole decreases the fatigue limit and results in the prolongation of the non-propagating crack. (3) For the non-propagating crack, the threshold stress intensity factor range ΔKth decreases with a decrease in the crack length.
|Number of pages||9|
|Journal||Transactions of the Japan Society of Mechanical Engineers Series A|
|Publication status||Published - 1987|
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering