Accession Number : AD0746950

Title :   Effects of Nonmetallic Inclusions on Stage II Fatigue Crack Propagation in a Low Alloy Steel.

Descriptive Note : Technical rept.,

Corporate Author : WATERVLIET ARSENAL N Y

Personal Author(s) : Thornton,Peter A.

Report Date : MAY 1972

Pagination or Media Count : 106

Abstract : The dependence of fatigue crack growth rate on stress intensity factor range was shown to be more sensitive to the morphology and distribution of inclusions than to the total quantity of nonmetallistics present. Higher crack growth rates were obtained in specimens containing relatively small sulphides that were irregularly shaped and clustered or aligned. Conversely, the lowest crack growth rates were obtained in specimens containing well distributed, spherical oxides. Fractographic examination accompanied by energy dispersive x-ray analysis of inclusions 'in situ' on fracture surfaces illustrated the involvement of inclusions in the fracture process. Also, these inspections verified the metallographic observations. (Author)

Descriptors :   (*STEEL, FRACTURE(MECHANICS)), TENSILE PROPERTIES, IMPACT TESTS, CRACK PROPAGATION, DEOXIDATION(METALLURGY), DEFECTS(MATERIALS), THESES

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE