CERTAIN REGULARITIES IN THE FORMATION OF THE SIGMA PHASE IN STEEL WITH 18( CR AND 14( MN
Abstract
IN A STEEL WITH 18% Cr and 14% Mn after quenching in water from 1100 degrees, the decomposition of the ferrite upon tempering begins with precipitation of carbides arranged in chains along the grain b undaries. The process of precipitation of the sigma-phase is accompanied by a considerable rise in hardness. The precipitation of the carbides in tempering results in a reduction of strength and ductility, while decomp ition of the ferrite with for ation of the sigma-phase sharply increases the strength and diminishes the ductility of the steel. The activation energy of the process of precipitation of the sigma-phase (in the 500 - 700 temperature intervals), computed in terms of the curve of change in hardness upon tempering constitutes approximately 29 kcal/gm/atom. If the tempering time is constant, the particle size of the sigma-phase will be greater, the higher the temperature of tempering. Moreover, the particle size is exponentially related to the tempering temperature. For 100 hrs tempering time, the activation energy of growth of sigma-phase particles is approximately 14 kca /gm/atom. (Author 0
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 28, 1961
- Accession Number
- AD0264613
Entities
People
- I.f. Zudin
- O.a. Bannykh
Organizations
- National Air and Space Intelligence Center