温度对Zr-Sn-Nb合金致应力碘腐蚀开裂的影响

Effect of Temperature on Iodine-Induced Stress Corrosion Cracking of Zr-Sn-Nb Alloy

研究了N18和N36锆合金在不同温度下的碘致应力腐蚀开裂(SCC)行为,用扫描电镜进行了断口分析。结果表明,对于再结晶状态的锆合金,随着试验温度升高,K_(ISCC)(临界应力强度因子)降低,裂纹萌生所需的应力降低,裂纹萌生所需的时间也变短；对于去应力状态的N18合金,试验温度从300℃增加到350℃,K_(ISCC)基本不变,裂纹萌生所需的应力降低,裂纹萌生所需的时间也变短；随着试验温度升高,断口上的腐蚀产物增多。

The behaviors of iodine-induced stress corrosion cracking of N 18 and N36 alloys at different temperatures have been investigated. The characterizations of the SCC fractures have been examined by SEM. The results show that, for recrystallized zirconium alloys, the critical stress intensity thctor KISCC and stress decrease, as well as critical time shortens with test temperature increasing; for stress relieved zirconiuln alloys, the critical stress intensity factor Klscc almost keeps unchanged, but the critical stress decreases and critical time shortens when temperature changes from 300℃ to 350℃. The higher temperature is, the more the corrosion product is.