CREVICE CORROSION CHARACTERISTICS OF ZR-2 .5WT-PERCENT-NB ALLOY AND SUS403MOD IN HIGH-TEMPERATURE PURE WATER

Crevice corrosion characteristics of 13% chromium martensitic stainles s steel bearing 3.5% nickel and zirconium alloy containing 2.5% niobiu m (Zr-2.5wt%Nb) were investigated in high temperature pure water. Corr osion of the stainless steel occurred in the crevice, while corrosion of the Zr-2.5wt%Nb was inhibited. Corrosion pits were formed on the st ainless steel in the early period of the corrosion test. However, thes e pits were repassivated in the subsequent corrosion test and the pits did not propagate. The Zr-2.5wt%Nb;Nb alloy absorbs the hydrogen gene rated by the corrosion of the stainless steer and the hydrogen pick up is correlated with the corrosion of the stainless steel.