MARTENSITIC TRANSFORMATION AND PLASTIC DEFORMATION IN IRON ALLOY SINGLE CRYSTALS.

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)

Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1962
Accession Number
AD0282176

Entities

People

  • J. F. Breedis
  • W. D. Robertson

Organizations

  • Yale University

Tags

DTIC Thesaurus Topics

  • Alloys
  • Austenite
  • Crystals
  • Iron
  • Iron Alloys
  • Martensite
  • Plastic Deformation
  • Single Crystals
  • Stresses
  • Tensile Stress

Readers

  • Materials Science and Engineering.
  • Powder metallurgy of Titanium alloys.