CAJ | 학술논문

主要研究了热老化对主泵泵壳材料CF8在室温和350℃温度下拉伸性能以及失效评定曲线的影响。对经历不同老化时间的试样进行恒应变速率下的拉伸试验，采用Ramberg-Osgood （R-O）模型对拉伸真应力-真应变曲线进行分析，并将分析结果用于失效评定曲线的计算。结果表明，随热老化时间延长，室温和350℃温度下材料的抗拉强度均不断提高，断后延伸率有所下降；在小应变范围内，R-O模型能够较准确预测材料的真应力-真应变曲线；采用英国R6标准方法二得到不同老化阶段材料的失效评定曲线，结果显示在部分区域，如采用未老化材料的失效评定曲线，则评定结果将偏于不安全。
주요연구료열노화대주빙빙각재료CF8재실온화350℃온도하랍신성능이급실효평정곡선적영향。대경력불동노화시간적시양진행항응변속솔하적랍신시험，채용Ramberg-Osgood （R-O）모형대랍신진응력-진응변곡선진행분석，병장분석결과용우실효평정곡선적계산。결과표명，수열노화시간연장，실온화350℃온도하재료적항랍강도균불단제고，단후연신솔유소하강；재소응변범위내，R-O모형능구교준학예측재료적진응력-진응변곡선；채용영국R6표준방법이득도불동노화계단재료적실효평정곡선，결과현시재부분구역，여채용미노화재료적실효평정곡선，칙평정결과장편우불안전。
The effects of thermal aging on tensile properties and failure assessment curves were studied for casting autenitic stainless steel CF8,which is used for the reactor coolant pump casing.Static tensile tests on samples with different thermal aging time were conducted with a constant strain rate.Then,a model of Ramberg-Osgood was used to analyze true stress-strain curves.Finally,the fitted parameters of R-O formula were used to calculate the failure assessment curve (FAC ).The results show that the tensile strength of material gradually increased while the elongation percentage changed reversely with the ther-mal aging time increasing at both room temperature and 350 ℃.The curve calculated by R-O model fits well with the true stress-strain curve when the loading strain is small.Failure assessment curves for ma-terial with different aging time were calculated by R6 option 2 method.It was found that the FAC for un-aged material is not reliable for thermal aged material in some cases.