A continuous wave, YAG laser was employed to perform the heat treatment of the surface of precracked specimens, and rotational-bending fatigue tests have been conducted on laser-treated specimens. The results obtained are summarized as follows: (1) Laser surface treatment has a beneficial effect of increasing the fatigue strength of a steel specimen with the crack shallower than the surface hardening depth. (2) A small fatigue crack at the specimen surface which has been laser treated is still closed even under application of static tensile stress equal to the fatigue limit of the specimen. This suggests that crack closure is a dominant controlling factor of the nonpropagation of a fatigue crack in the laser treated area.
|ジャーナル||Transactions of the Japan Society of Mechanical Engineers Series A|
|出版ステータス||Published - 1991|
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