Accession Number : AD0626225

Title :   SOLIDIFICATION OF IRON BASE ALLOYS AT LARGE DEGREES OF UNDERCOOLING.

Descriptive Note : Interim rept. 1 Oct 64-30 Sep 65,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF METALLURGY

Personal Author(s) : Kattamis,T. ; Flemings,M. C.

Report Date : 30 SEP 1965

Pagination or Media Count : 120

Abstract : Study was made of structure and solute redistribution in bulk samples of iron and nickel base alloys undercooled up to 300 C. Alloys undercooled were iron-25 per cent nickel, iron-25 per cent nickel-0.3 per cent sulphur, iron-25 percent nickel-1.4 per cent carbon, nickel-25 percent copper, and AISI 4330 low alloy steel. Detailed morphology studies were conducted on nickel-25 per cent copper alloy. Results were nearly identical to those obtained earlier in iron-25 per cent nickel alloy. Cursory examination of other alloys indicates results obtained for the iron-nickel and nickel-copper alloy can be expected to apply to substantial degree to these systems. The dendrite element spacing, for cylindrical and spherical morphologies, decreases with increasing undercooling, increasing rate of heat extraction from the bulk sample, and decreasing distance from a chill surface. The transition of cylindrical to spherical morphology depends only on initial undercooling. The distribution of solute was studied metallographically and by electron microanalysis. Nickel concentration profiles and isoconcentration curves were established and segregation ratios measured in both internally chilled and non-internally chilled iron-25 per cent nickel specimens undercooled various amounts. (Author)

Descriptors :   (*IRON ALLOYS, FREEZING), (*NICKEL ALLOYS, FREEZING), (*STEEL, FREEZING), COPPER ALLOYS, CARBON, COOLING, PHASE STUDIES, MICROSTRUCTURE, CRYSTALLIZATION, DIFFUSION, MELTING, CASTINGS

Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE