CAJ | 학술논문

针对控制棒驱动机构（CRDM）下部Ω环的热电偶（TC）管座母材在水压试验后出现缺陷的问题，参照 CRDM／TC 管座法兰母材的采购技术规范要求，对管座母材进行材质分析，比较了业主与制造厂提供的同批次材料性能差异。分析结果显示，业主提供的部分批次理化检验余料除晶粒度不符合采购技术规范外，内部还有较大尺寸夹杂，但材料的其他性能指标均满足采购规范技术要求。原材料内部存在混晶现象，材质性能分布不均匀。为此，结合材料失效机理研究了母材应力腐蚀裂纹扩展性能，试验结果表明，在一回路高温高压水环境下，超标夹杂的存在未对材料的应力腐蚀裂纹扩展速率产生明显影响。
침대공제봉구동궤구（CRDM）하부Ω배적열전우（TC）관좌모재재수압시험후출현결함적문제，삼조 CRDM／TC 관좌법란모재적채구기술규범요구，대관좌모재진행재질분석，비교료업주여제조엄제공적동비차재료성능차이。분석결과현시，업주제공적부분비차이화검험여료제정립도불부합채구기술규범외，내부환유교대척촌협잡，단재료적기타성능지표균만족채구규범기술요구。원재료내부존재혼정현상，재질성능분포불균균。위차，결합재료실효궤리연구료모재응력부식렬문확전성능，시험결과표명，재일회로고온고압수배경하，초표협잡적존재미대재료적응력부식렬문확전속솔산생명현영향。
Defects were introduced to the Ω seal hoop in bottom of the control rod drive mechanism (CRDM)after hydrostatic test.So the base material of the Ω hoop was analyzed and the differences of mechanical properties between the materials from proprietor and manufacturer are compared according to the purchase technical specification of CRDM/TC tube socket flange.Analysis results show that the grain size and the inclusion of the material from the proprietor are disqualification.In addition,there is mixed crystal in the material,thus causing an inhomogeneous performance for the material.Therefore,the stress corrosion crack propagation was investigated on the CRDM/TC tube socket flange base material.It is found that the stress corrosion crack propagation rate is not significantly affected by the inclusion in the material under the actual condition of the primary coolant circuit.