Accession Number : AD0282176

Title :   MARTENSITIC TRANSFORMATION AND PLASTIC DEFORMATION IN IRON ALLOY SINGLE CRYSTALS.

Descriptive Note : TR 6,

Corporate Author : YALE UNIV NEW HAVEN CONN HAMMOND LAB

Personal Author(s) : Breedis ,J. F. ; Robertson,W. D.

Report Date : JUL 1962

Pagination or Media Count : 17

Abstract : The characteristics of the deformation of austenite, and the influence on the martensitic transformation of elastic tensile stress and prior plastic deformation were studied in single crystals of Fe-16Cr-25Ni, Fe-16Cr-12Ni, and Fe-30Mi alloys. The influence of existing transformation products on the plastic deformation of the remaining austenite was observed. In general, small amounts of martensitic structures are formed under elastic stress at temperatures as high as 200 C above the spontaneous transformation temperature to strengthen crystals against subsequent deformation by slip. Large quantitiesof randomly dispersed martensite also decrease the extent of easy glide. Prior deformation on a single slip system suppresses the subsequent athermal transformation in both Fe-16Cr-12Ni and Fe-30Ni single crystals. From the drastically different behavior under stress observed at temperatures slightly above the spontanevous transformation temperature in Fe-16Cr-12Ni and Fe-30Ni, it is evident that different transformation mechanisms are operative in these alloys. Several possible transformation mechanisms are proposed for the Fe-16Cr-12Ni composition. A mechanism involving an intermediate h.c.p. structure is best suggested by the observations. (Author)

Descriptors :   (*IRON ALLOYS), TRANSFORMATIONS, MARTENSITE, DEFORMATION, SINGLE CRYSTALS, AUSTENITE, TENSILE PROPERTIES, SHEAR STRESSES, TEMPERATURE, STAINLESS STEEL

Distribution Statement : APPROVED FOR PUBLIC RELEASE