Abstract
A comparsion study of corrosion resistances on various thermal mechanical treated zircaloy - 4 specimens were conducted on a 500℃ autoclave filled with 1, 500 psi steam. The tested specimens were then surface examined and weighted. It was observed that air cooled specimens after 1050 ℃ / lhr, beta treatment and same specimens followed by cold rolling before and after 650℃ / lhr, alpha - anneal show a serlous nodular corrosion. On the other hand, water quenched opecimens after beta - treatment with or without cold rolling and alpha anneal exhibit a good nodular corrosion resistance and minor difference between each other. TEM examinations of all the thermal mechanical treated specimens have been carried out. A relatively small and dense chain - like prcipitates are developed in beta - quencheo specimens with or without the cold rolling and alpha anneal. The highest population of chain - like precipitates is observed in the beta - quenched specimen followed by 30% cold rolling and alpha - anneal which also displays the best resistance to nodular corrosion.