Accession Number : AD0285459

Title :   THE ROLE OF FINE STRUCTURE IN THE MECHANICAL BEHAVIOR OF METALS

Descriptive Note : Quarterly rept. no. 11, 11 Jul-10 Sep 62

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s) : COHEN,MORRIS ; AVERBACH,B.L.

Report Date : 01 OCT 1962

Pagination or Media Count : 3

Abstract : Results are summarized on the effects of plastically deforming austenite on the strength of subsequently formed martensite in an iron-31.9 weight percent nickel - 0.017 weight percent carbon alloy. The deformation of the austenite did not change the Ms temperature, but the amount of martensite produced upon quenching to liquid nitrogen decreased with increasing reduction in thickness. The tensile properties of (a) deformed austenite, (b) martensite with prior deformation of the austenite, and (c) deformed martensite (originally obtained by refrigerating annealed austenite) were determined, and the corresponding 0.2 percent yield strengths of transverse and longitudinal specimens are shown. The ductility of the martensite as a function of deformation of the prior austenite exhibited a striking difference when compared with deformed martensite. The structures of deformed austenite and the resulting martensitic structures were studied by transmission electron microscopy. Attempts were made to measure the particle sizes and lattice strains in the ausformed martensite by x-ray line-breadth analysis. The strains in the ausformed martensite increased. The strengthening of the martensite by ausforming was relatively modest because of the low carbon content of the iron-nickel alloy under study. (Author)

Descriptors :   *GRAIN STRUCTURES (METALLURGY), *IRON ALLOYS, *NICKEL ALLOYS, *PROCESSING, ALLOYS, AUSTENITE, DEFORMATION, ELASTIC PROPERTIES, HEAT TREATMENT, HYPERFINE STRUCTURE, MARTENSITE, METALS, MICROSTRUCTURE, TENSILE PROPERTIES, TESTS

Distribution Statement : APPROVED FOR PUBLIC RELEASE