Accession Number : AD0701892

Title :   OPTIMUM FATIGUE CRACK RESISTANCE.

Descriptive Note : Technical rept.,

Corporate Author : WATERVLIET ARSENAL N Y

Personal Author(s) : Thropp,Joseph F. ; Miller,G. A.

Report Date : JAN 1970

Pagination or Media Count : 35

Abstract : An evaluation is made of the influence of mechanical properties on fatigue-crack growth rate. Data representing 4340 and modified 4330 steel show that for levels of the stress intensity factor K below about 40 ksi sq root of (in.) mechanical properties have little influence on growth rate. However, at higher K-levels both the product of Young's modulus, yield strength and fracture toughness, and the product of Young's modulus, tensile strength and true strain at fracture seem to be reasonable indices of crack growth resistance. For K-levels above 40 ksi sq root of (in.) minimum fatigue-crack growth rate is provided by tempering 4340 and modified 4330 at temperatures of about 1000 and 1100 F, respectively. (Author)

Descriptors :   (*STEEL, FATIGUE(MECHANICS)), (*CRACK PROPAGATION, STEEL), FRACTURE(MECHANICS), STRESSES, TEMPERING

Subject Categories : Metallurgy and Metallography
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE