T-22合金在高温气冷堆非纯氦气中脱碳和氧化腐蚀行为研究

Study on Decarburization and Oxidation Corrosion Behavior of T-22 Alloy in Impure Helium of High-temperature Gas-cooled Reactor

高温气冷堆的主冷却剂氦气中含有痕量杂质,其在高温环境下会与设备的合金材料发生反应从而造成材料腐蚀。在950℃、4种非纯氦气中开展高温气冷堆蒸汽发生器备选材料T-22合金的腐蚀试验,腐蚀时间为50 h,然后通过称重、扫描电镜、X射线能谱、电子探针显微分析仪以及碳硫分析仪对腐蚀后的T-22合金进行表征分析。研究表明,T-22合金在6种腐蚀情况下均未形成连续致密氧化层,合金内部均出现内氧化现象且均近乎发生完全脱碳,脱碳量达92.86%;腐蚀后的T-22合金的质量变化均很小,腐蚀50 h时合金已发生充分脱碳。

Helium in the main coolant of high-temperature gas-cooled reactor(HTGR)contains trace impurities,which reacts with the alloy materials of the equipment at high temperature and cause corrosion of the materials.The corrosion test of T-22 alloy,an alternative material for high-temperature gas-cooled reactor steam generator,is carried out in four kinds of impure helium at 950℃,and the corrosion time is 50 h.Then the corroded T-22 alloy is characterized by weighing,scanning electron microscope,X-ray energy spectrum,electron probe microanalyzer and carbon sulfur analyzer.The results show that T-22 alloy does not form a continuous dense oxide layer under six corrosion conditions,internal oxidation occurs in the alloy and complete decarburization occurs,and the amount of decarburization is up to 92.86%.The mass change of T-22 alloy after corrosion is very small,and the alloy has been fully decarburized after corrosion for 50 h.