Accession Number:

AD0281894

Title:

THE STRENGTH OF MARTENSITE,

Descriptive Note:

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s):

Report Date:

1962-03-01

Pagination or Media Count:

33.0

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

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE