摘要
采用慢应变速率试验(SSRT)研究了12Cr-F/M钢在25MPa,550℃和650℃的超临界水(SCW)中的机械性能,以及在550℃的SCW中的应力腐蚀开裂(SCC)倾向。同时通过均匀腐蚀试验研究了12Cr-F/M钢在550℃/25MPa的SCW中的腐蚀性能。SSRT结果表明,12Cr-F/M钢在550℃/25MPa时具有优良的机械性能,当温度升高到650℃时其机械强度下降明显,但延伸率基本不变。由断口SEM形貌可知,12Cr-F/M钢具有沿晶应力腐蚀开裂(IGSCC)倾向。均匀腐蚀结果表明,12Cr-F/M钢在550℃/25MPa的SCW中的腐蚀性能较差,其腐蚀增重呈现出抛物线生长规律,1 000h后其腐蚀增重达741mg/dm2。同时发现其在600h时表面氧化膜出现裂纹,1 000h时后观察到氧化膜发生剥落,而氧化膜脱落主要是因为在降温过程中基体与氧化物间不一致的热膨胀系数造成的。
The mechanical properties of 12Cr-F/M steel at 550/650 ℃ and SCC performance at 550 ℃ in supercritical water(SCW)were studied using slow strain rate testing(SSRT).And the general corrosion behavior of 12Cr-F/M steel in SCW at 550 ℃ was studied.The results of SSRT showed that 12Cr-F/M steel had good mechanical properties in SCW at 550℃,and its mechanical strength decreased significantly when the temperature was 650℃,but its elongation was basically unchanged.The result of ex-situ scanning electron microscopy(SEM) showed that 12Cr-F/M steel had IGSCC susceptibility in SCW at 550℃.The result of general corrosion experiment in supercritical water showed that 12Cr-F/M steel had low resistance to general corrosion,and the weight gain was subject to Parabolic growth law.At 600h,the rupture of oxide film occurred,and the oxide film suffered exfoliation at 1 000h.It is assumed that this exfoliation resulted from the inconsistency of thermal expansion between the matrix and the oxide during the cooling period.
出处
《腐蚀与防护》
CAS
北大核心
2014年第5期434-437,共4页
Corrosion & Protection
基金
大型先进压水堆核电站重大专项(2011ZX06004010)
关键词
腐蚀
应力腐蚀开裂
机械性能
超临界水
corrosion
SCC
mechanical performance
supercritical water(SCW)
