Beck, F. H.
Schoefer, E. A.
Executive vice president, Alloy Casting,
Flowers, J. W.
Army Materials Research Agency, Watertown Arsenal, Watertown, Mass.
Fontana, M. G.
Professor and chairman, The Ohio State University, Columbus, Ohio.
Pages: 16 Published: Jan 1965
As normally made commercially, the CF type cast alloys (19 per cent chromium, 9 per cent nickel) are austenitic, but may contain from 0 to 50 per cent ferrite depending on the balance among the constituent elements within the chemical ranges specified for the various grades. Statistical analysis of mechanical properties of many heats produced by a number of foundries has demonstrated that strength and ductility are functions of the ferrite content in these alloys. At room temperature, strength increases substantially but ductility decreases only slightly with increasing ferrite content. A series of alloys has been studied to determine the effect of ferrite content on their strength at elevated temperature (up to 1200 F) and on their susceptibility to form sigma phase after long exposure at elevated temperature. Results indicate that alloys containing 20 to 30 per cent ferrite have improved strength without detrimental loss of ductility or impact strength at temperatures of 800 F or below.
Paper ID: STP43742S