EFFECTS OF ALLOYING ELEMENTS ON THE TENSILE PROPERTIES AND OXIDATION BEHAVIOR OF MODIFIED ZIRCALOY-4 IN 360-DEGREES-C WATER

The effects of oxygen and tin contents on the tensile properties and o xidation behavior of modified Zircaloy-4 (Zry-4) were investigated. Th e modified alloys were prepared by changing the chemical compositions of Zry-4; the tin contents were decreased from 1.0 wt% to zero while o xygen increased from 0.1 to 0.8 wt%, 0.1 wt% Nb was added and the amou nts of Fe and Cr were kept 0.1 and 0.2 wt%, respectively. The UTS incr eased significantly with the oxygen content. 0.2 wt% oxygen could comp ensate the decrease in strength resulted from the reduction of tin con tent from 1.0 wt% to zero. The weight gain in water at 360 degrees C u nder a pressure of 180 bar increased with tin and oxygen contents. The alloy with tin and oxygen contents of zero and 0.1 wt% showed the low est weight gain for 120 days of oxidation test.