热老化对主泵泵壳材料失效评定曲线的影响研究  

Research on Thermal Aging Effect on Failure Assessment Curve of Nuclear Coolant Pump Casing Material

作　　者：余伟炜[1] 田阳[2] 薛飞[1] 蒙新明[1] 

机构地区：[1]苏州热工研究院有限公司,江苏苏州215004 [2]天津大学化工学院,天津300072

出　　处：《压力容器》2014年第5期23-29,12,共8页Pressure Vessel Technology

基　　金：国家科技重大专项(2011ZX06004-009-08);江苏省国际科技合作计划项目(BZ2012026)

摘　　要：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。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.

关 键 词：主泵泵壳 热老化 Ramberg-Osgood模型 真应力-应变曲线 失效评定曲线 

分 类 号：TH142[一般工业技术—材料科学与工程] TG142.2[机械工程—机械制造及自动化]