Accession Number : AD0737791

Title :   Local Yielding Attending Fatigue Crack Growth.

Descriptive Note : Final technical rept. 15 Jun 70-15 Sep 71,

Corporate Author : BATTELLE COLUMBUS LABS OHIO

Personal Author(s) : Hahn,G. T. ; Hoagland,R. G. ; Rosenfield,A. R.

Report Date : NOV 1971

Pagination or Media Count : 46

Abstract : Fatigue crack growth rate measurements were performed at 100C on an Fe-3Si steel in three thickness conditions and at different Delta K-levels. The test pieces were subsequently sectioned and etched to reveal the plastic deformation attending crack growth both on the surface and in the interior. Unlike preceding studies, the Fe-3Si steel displayed classical cyclic crack growth: well-defined fatigue striations with a spacing close to the per-cycle growth rate, and essentially the same growth rates that have been reported for low and medium strength steels. A highly strained region, about 1/5 the size of the monotonic plastic zone, is identified as the cyclic plastic zone. (Author)

Descriptors :   (*STEEL, CRACK PROPAGATION), FATIGUE(MECHANICS), STRESSES, STRAIN(MECHANICS), ETCHING, SILICON ALLOYS

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE