A METALLOGRAPHIC STUDY OF ABNORMAL GRAIN-GROWTH DURING AGING OF A BETA-QUENCHED ZR-1.14 WT-PERCENT CR-0.08 WT-PERCENT FE ALLOY (REPRINTED FROM METALLOGRAPHY, VOL 13, PG 249-266, 1980)

Results are reported of a detailed optical and electron metallographic study of the effects of variations in quenching rate from the beta-ph ase and aging temperature in the alpha + ZrCr2 phase region, on the re crystallization and grain growth characteristics of Zr-1.14 wt% Cr-0.0 8 wt% Fe alloy used for nuclear fuel sheathing. It is shown that certa in quenching rates, which produce a mixed martensitic-Widmanstatten st ructure, should be avoided during the fabrication of fuel sheathing, s ince recrystallization and grain growth occurs at a much lower tempera ture than a material quenched at such a rate that the structure is who lly Widmanstatten or wholly martensitic. Preaging at 350 or 450 degree s C prior to the high-temperature (700-750 degrees C) aging reduces th e incidence of recrystallization and grain growth.