INVESTIGATION OF SOLIDIFICATION OF HIGHSTRENGTH STEEL CASTINGS
Abstract
A numerical technique was employed to compute microsegregation in alloys in which (a) the final solidification temperature and composition is variable, and (b) substantial diffusion occurs in the solid during and after solidification. In iron-26 per cent nickel alloy, segregation ratio obtained is from 1.15 to 1.28 depending on solidification conditions. These results are in qualitative agreement with theory. Dendrite morphology was examined in iron- nickel alloys containing from 10 to 26 per cent nickel, and in iron-nickel- carbon alloys containing about 26 per cent nickel and up to 0.42 per cent carbon. 'Cellular' structures result in the alloys studied under conditions of low solute content and high cooling rate. Lower cooling rates and higher solute contents produce a more complex dendrite structure, with secondary and tertiary branching. Primary dendrite arm spacing in the ingots studied ranged from about 40 to 700 microns, depending on alloy analysis and cooling rate. Dendrite arm spacing in the alloys studied generally increase with (a) decreasing cooling rate, (b) increasing nickel content (at least in the range of 15 to 26 per cent nickel, and (c) carbon additions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1964
- Accession Number
- AD0624987
Entities
People
- H. D. Brody
- Merton C. Flemings
- R. V. Barone
Organizations
- Massachusetts Institute of Technology