Abstract
With aiming to clarify the environmental effects on crack growth behavior of wrought alloy 625 at 750℃, growth rate and formed oxide were evaluated in air and steam. There are no remarkable difference in the growth rate in air and steam. In addition, the formed oxides morphologies and compositions were similar between two. Two layer oxide film were identified in both environment. Outer layer was nickel rich spinel type oxide and inner was continuous Cr_2O_3 compact oxide. It was pointed out that there was consistency between the growth rate and oxidation behavior.