Accession Number : AD0281894

Title :   THE STRENGTH OF MARTENSITE,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s) : Winchell ,P. G. ; Cohen,Morris

Report Date : 01 MAR 1962

Pagination or Media Count : 33

Abstract : Fe-Ni-C alloys were selected to determine the role of C in the strengthening of virgin (untempered) martensite. Martensites formed at subzero temperatures were maintained at low-temperature levels for the studies. The axial ratio of the tetragonal lattice increased with the C concentration, but there was an extra tetragonality independent of C and which is thought to result from the presence of stacking faults. The extra tetragonality disappeared on aging above room temperature where the regular tempering reactions occur. The C-dependent strengthening of virgin martensite can be described as a solid-solution hardening phenomenon. The fine structure of the martensite is thought to be a contributory factor in the over-all strengthening. In addition, at temperatures above about -60 C, age hardening due to carbide precipitation provides a further component of strengthening which increases with the carbon content; this increment is relatively small compared to the solid-solution effect. (Author)

Descriptors :   *STEEL, AGING (PHYSIOLOGY), ATOMS, AUSTENITE, CARBON, CARBON ALLOYS, CRYSTAL LATTICES, CRYSTAL STRUCTURE, IRON ALLOYS, NICKEL ALLOYS, PHASE STUDIES, SOLIDS, SOLUTIONS(MIXTURES)

Distribution Statement : APPROVED FOR PUBLIC RELEASE