Study on Fast Fracture Evaluation Method for Reactor Pressure Vessel with Excessive Carbon Content
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摘要: 按照RCC-M规范对设备进行快速断裂评价时,材料的初始无延性转变温度是重要的输入条件之一。材料中的碳含量超标会影响材料初始无延性转变温度,但目前2者之间还没有定量关系。当反应堆压力容器(RPV)出现碳含量超标时,为保证结构完整性,必须在缺乏定量关系的情况下完成结构的快速断裂分析。本研究对碳含量超标情况下的反应堆压力容器的快速断裂评价方法进行了研究,并以发生碳含量超标的反应堆压力容器堆芯段筒体为例,考虑了筒体的缺陷修复情况,通过反算满足规范要求的最高初始无延性转变温度,对反应堆压力容器堆芯段筒体的快速断裂情况进行了分析评估。该方法可为碳含量超标的压力容器运行和在役检测提供技术支持。
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关键词:
- 反应堆压力容器(RPV) /
- 快速断裂 /
- 初始无延性转变温度 /
- 碳含量
Abstract: The initial non-ductile transition temperature is an important input parameter in fast fracture evaluation according to the RCC-M code. The initial non-ductile transition temperature (RTNDT) will be affected by the carbon content, but there is no quantitative relationship between them. When the carbon content of the reactor pressure vessel exceeds the standard, it is necessary to complete the fast fracture evaluation without quantitative relationship to ensure the integrality of RPV. In this paper, the evaluation method of the fast fracture of RPV with excessive carbon content is studied. Taking the RPV core barrel with excessive carbon content as an example, the defect repair is considered, and the fast fracture analysis and evaluation are carried out by calculating the maximum initial non-ductile transition temperature. This method can support the operation and the in-service inspection of the pressure vessels with excessive carbon content. -
表 1 KJC的取值
Table 1. Value of KJC
温度范围 材料 KJC/(MPa·m0.5) T≥200℃ wS≤0.005 200 0.005<wS ≤0.008 170 0.008<wS ≤0.011 155 0.011<wS ≤0.015 135 焊缝处 170 T≤50℃ wS≤0.005 245 0.005<wS ≤0.008 205 0.008<wS ≤0.011 190 0.011<wS ≤0.015 175 焊缝处 205 wS—母材的硫含量,% 表 2 16MND5的材料性能
Table 2. Material Properties of 16MND5
温度/℃ 20 50 100 150 200 250 300 350 热导率/
(mW·mm−1·K−1)37.7 38.6 39.9 40.5 40.5 40.2 39.5 38.7 比热/[J·(kg·K)−1] 447.1 460.3 484.0 503.6 523.9 547.1 567.1 590.0 线胀系数/10−6K−1 11.22 11.63 12.32 12.86 13.64 14.27 14.87 15.43 杨氏模量/GPa 204 203 200 197 193 189 185 180 泊松比 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 屈服强度/MPa 345 340 326 318 311 308 303 299 表 3 E309L和E308L的材料性能
Table 3. Material Properties of E309L and E308L
温度/℃ 20 50 100 150 200 250 300 350 热导率/
(mW·mm−1·K−1)14.7 15.2 15.8 16.7 17.2 18.0 18.6 19.3 比热/[J·(kg·K)−1] 461.9 480.0 500.2 526.1 533.9 546.8 550.7 557.3 线胀系数/10−6K−1 16.40 16.84 17.23 17.62 18.02 18.41 18.81 19.20 杨氏模量/GPa 197 195 191.5 187.5 184 180 176.5 172 泊松比 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 表 4 材料的无延性转变温度升高值
Table 4. Rise of RTNDT of Material
时间/
a快中子注量/
1019 cm−2辐照老化导致的
ΔRTNDT/℃总ΔRTNDT/℃ 母材 热影响区 10 0.4379 18.24 18.24 33 20 0.8758 25.79 25.79 33 30 1.314 31.58 31.58 33 40 1.752 36.47 36.47 36.47 表 5 不同状态下允许的最高RTNDT
Table 5. Maximum Allowable RTNDT under Different Conditions
状态 时间/a 裂纹深度/mm 允许的最高RTNDT/℃ 设计状态 40 20 −3 缺陷修复状态 40 20 −19 a=10 mm 10 12.407 −5 20 15.382 −10 30 21.157 −16 40 29.067 −26 a=6.2 mm 10 7.343 9 20 8.828 3 30 10.907 −4 40 13.517 −10 表 6 快速断裂计算结果
Table 6. Results of Fast Fracture Calculation
初始裂纹
深度/mm时间/
a裂纹深度/
mm应力强度因子/
(MPa·m0.5)限值/(MPa·m0.5) −10℃ −15 ℃ 6.2 10 7.343 57.6 84.1 94.7 20 8.828 63.1 84.1 94.7 30 10.907 70.0 84.1 94.7 40 13.517 77.8 77.8 87.1 10 10 12.407 74.6 84.1 94.7 20 15.382 82.8 84.1 94.7 30 21.157 96.8 84.1 94.7 40 29.067 113.1 77.8 87.1 -
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