Accession Number : AD0706084

Title :   GRAIN BOUNDARY SEGREGATION OF IMPURITIES IN METALS AND INTERGRANULAR BRITTLE FRACTURE.

Descriptive Note : Technical rept.,

Corporate Author : CARNEGIE-MELLON UNIV PITTSBURGH PA METALS RESEARCH LAB

Personal Author(s) : Low,John R. , Jr. ; Goodman,Stephen R. ; Smith,Craig L.

Report Date : 01 MAR 1970

Pagination or Media Count : 41

Abstract : Progress report on two investigations of temper embrittlement in low alloy steels. Part 1 describes the development of a method of examining grain boundary segregation using neutron activation analysis of etching residues obtained from intergranular fracture surfaces. The method is capable of detecting antimony segregation at grain surfaces and of measuring the decrease in antimony with distance from the intergranular surface. Part 2 describes the development of a field ionization atom probe method of analysis applicable to polycrystalline, carbon-free alloys. Processing necessary to produce stable grain sizes of less than 0.5 micron diameter in the alloys of interest is also described. These small, grain sizes are necessary if the probability of finding a grain boundary in the FIM specimen tip is not to be prohibitively low. (Author)

Descriptors :   (*STEEL, *EMBRITTLEMENT), HEAT TREATMENT, GRAIN BOUNDARIES, DUCTILE BRITTLE TRANSITION, ANTIMONY ALLOYS, NEUTRON ACTIVATION, CHEMICAL ANALYSIS, IMPURITIES

Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE