Accession Number : AD0613970

Title :   GRAIN BOUNDARY SEGREGATION AND THE COLD WORK PEAK IN IRON CONTAINING CARBON OR NITROGEN,

Corporate Author : STANFORD UNIV CALIF DEPT OF MATERIALS SCIENCE

Personal Author(s) : Rudee,Mervyn L. ; Huggins,Robert A.

Report Date : MAR 1965

Pagination or Media Count : 25

Abstract : Samples of iron containing 0.07 weight % nitrogen or 0.015 weight % carbon have been given treatments similar to those used in cold work peak (CWP) measurements and examined by transmission electron microscopy. It was observed that the unusual and non-reproducible behavior of the carbon CWP can be explained by a strong tendency for carbon to form grain boundary precipitates at temperatures below those used for CWP measurements. These precipitates dissolved at the temperatures used in the CWP measurements. There was no evidence for nitrogen precipitation at grain boundaries. There was no indication of precipitation along dislocations in either carburized or nitrided samples given treatments similar to those of CWP measurements. Although it is possible that sub-electronmicroscopic clustering had occurred, this observation supports the theories of the CWP that are based on continuous atmospheres rather than on individual precipitates. (Author)

Descriptors :   (*IRON, IMPURITIES), NITROGEN, CARBON, GRAIN BOUNDARIES, ELECTRON MICROSCOPY, INTERNAL FRICTION, CRYSTAL DEFECTS

Distribution Statement : APPROVED FOR PUBLIC RELEASE