Accession Number : AD0782217

Title :   The Effect of Microstructure on the Fracture Toughness of Low-Alloy Steels.

Descriptive Note : Technical rept.,

Corporate Author : CALIFORNIA UNIV LOS ANGELES SCHOOL OF ENGINEERING AND APPLIED SCIENCE

Personal Author(s) : Ensha,S. ; Tetelman,A. S.

Report Date : MAY 1974

Pagination or Media Count : 198

Abstract : A theoretical model has been used to relate the cleavage fracture toughness of the low-alloy steels to their microstructure. The cleavage fracture toughness of low-alloy steels depends upon three metallurgical parameters: the microscopic cleavage strength, the yield strength, and the effective root radius. Variations in fracture toughness with microstructure can be explained through the effect of the microstructure on these parameters. The major objective of this investigation has been the study of the effect of microstructural variables on these parameters, and hence the effect of microstructure on fracture toughness. The theoretical model for the cleavage fracture toughness of the low-alloy steels can be successfully applied provided the assumptions are not strongly violated. This requires low microscopic cleavage strength/yield strength ratio values and low work-hardening rates. Lower temperatures and higher strain rates both favor these conditions. (Modified author abstract)

Descriptors :   *Steel, *Fracture(Mechanics), Microstructure, Yield strength, Temperature, Strain rate, Mathematical models

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE