用小尺寸R—CT试样研究核压力容器钢断裂韧性及与Charpy试样的比较

提出了一种用双边带深侧槽的小尺寸圆形紧凑拉伸试样评定核压力容器钢断裂韧性的单试样试验方法，给出了用该方法测定的两个厂家的核压力容器用Ａ５０８ＣＬ３钢的断裂韧性参数，还与Ｃｈａｒｐｙ试样的试验结果及大尺寸标准试样的试验结果进行了比较，研究结果表明，用双边带深侧槽的小尺寸Ｒ－ＣＴ试样测得的断裂韧性值比相同侧槽深度预制疲劳裂纹Ｃｈａｒｐｙ试样的测试值更接近有效断裂韧性值，所以，用于核压力容器断裂韧性的监     

用小尺寸R－CT试样研究核压力容器钢断裂韧性及与Charpy试样的比较

提出了一种用双边带深侧槽的小尺寸圆形紧凑拉伸试样评定核压力容器（ＲＰＶ）钢断裂韧性的单试作试验方法，给出了用该方法测定的两个厂家生产的核压力容器用Ａ５０８ＣＬ３钢的断裂韧性参数，还与Ｃｈａｒｐｙ试样的试验结果及大尺寸标准试样的试验结果进行了比较。研究结果表明：用双边带深侧槽的小尺寸Ｒ－ＣＴ试样测得的断裂韧性值比相同恻槽深度预制疲劳裂纹Ｃｈａｒｐｙ试样的测试值更接近有效断裂韧性值，所以，用于核压力容器断裂韧性的监测是可行的。     

用不同试样评定核压力容器用A508CL3钢动态断裂韧性的比较性研究

通过示波冲击试验，采用预制疲劳裂纹的半尺寸Ｃｈａｒｐｙ试样及标准Ｃｈａｒｐｙ试样评定了核压力容器用Ａ５０８ＣＬ３钢的动态断裂韧性，研究了试样尺寸对动态断裂韧性的温度转变特性的影响。研究结果表明，半Ｃｈａｒｐｙ尺寸试样在低温下较Ｃｈａｒｐｙ试样过高地估计了Ａ５０８ＣＬ３钢的动态断裂韧性，而在上平台温度以上稍低估了Ａ５０８ＣＬ３钢的动态断裂韧性，所评定出的动态断裂韧性的韧／脆转变温度也明显低于标准尺寸     

用Chaypy试样研究核压力容器钢的韧性转变温度曲线

用一个标准Ｃｈａｒｐｙ试样及试验过的该试样的两个半截试样所获得的８个“再造Ｃｈａｒｐｙ复合试样”评定核压力容器用Ａ５０８ＣＬ３钢冲击韧性或断裂韧性的温度转变曲线。研究结果表明，用这种方法可得到一条较为可靠而完整的核压力容器钢的冲击韧性或断裂温度的转变曲线。     

用Charpy试样研究核压力容器钢的韧性转变温度曲线

用一个标准Ｃｈａｒｐｙ试样及试验过的该试样的两个半截试样所获得的８个“再造Ｃｈａｒｐｙ复合试样”评定核压力容器用Ａ５０８ＣＬ３钢冲击韧性或断裂韧性的温度转变曲线。研究结果表明，用这种方法可得到一条较为可靠而完整的核压力容器钢的冲击韧性或断裂韧性随温度的转变曲线。这相当于在核监测计划中，只需取出一个Ｃｈａｒｐｙ试样即可得到完整的材料性能曲线，这对于提高核压力容器中子辐照脆化监测的可靠性很有价值，特别是对于运行时间较长（堆芯内监测试样数量已经不多）的核容器寿命预测和安全监视尤为重要。     

核监测用断裂韧性Charpy尺寸试样的合理设计

预制疲劳裂纹侧槽Charpy尺寸试样是一种经济、方便的评价核压力容器用钢弹塑性断裂韧性的单试样方法。本文就几种常用压力容器用钢详细研究了侧槽相对深度对断裂韧性及相应的稳定裂纹扩展量的影响,并和满足GB2038要求的大尺寸试样的试验结果进行了对比。研究结果表明,采用预制疲劳裂纹、侧槽相对深度为30%的Charpy尺寸试样及三点弯曲试验曲线上最大载荷前的能量,可以偏安全地评价裂纹开始扩展时材料的弹塑性断裂韧性,建立了核监测用断裂韧性试验Charpy尺寸试样的合理设计。此外,还研究了侧槽的拘束效应和对试样的加厚作用,对试验结果进行了理论解释。     

改进型A508CL3钢的中子辐照脆化性能研究

在高通量工程试验堆对国产反应堆压力容器用Ａ５０８ＣＬ３钢进行了中子辐照脆化性能试验，并利用示波冲击分析了辐照前试样的动态断裂过程。研究结果表明：改进型Ａ５０８ＣＬ３钢锻件具有良好的抗中子辐照脆化性能，ＲＰＶ钢可以立足限国内生产。     

核压力容器钢冲击断口剪切面积百分比的估算方法

在核压力容器钢的中子辐照脆化评价中,断口剪切面积百分比是一个重要的参数。但此参数不易直接测量,对于辐照后的放射性试样其测量更加困难。本文采用Charpy-V示波冲击试验,并根据计算机采集得到的完整记录冲击过程的载荷－位移曲线,即可确定相应的载荷特征值,同时估算出断口剪切面积百分比。该估算方法用于计算核压力容器钢因中子 辐照引起的脆性转变湿度的变化值,其计算结果较为准确且计算方法也简便,现已成功地应用于大亚湾核电站压力容器的辐照监督试验。     

国产508—Ⅲ钢低周疲劳和动态断裂韧度试验研究

５０８－Ⅲ钢是国际上核一级压力容器常用的材料，但国产５０８－Ⅲ钢的疲劳和断裂性能尚未见报导。本文研究了国产５０８－Ⅲ钢锻件的低周疲劳和动态断裂韧度。通过试验，得到了５０８－Ⅲ钢的设计疲劳曲线和ｋｋｌ－（Ｔ－ＲＴＮＤＴ）曲线，并与ＡＳＭＥ规范和ＲＣＣ－Ｍ规范相应的基准曲线进行了比较。     

提高核压力容器中子辐射脆化断裂韧性监测可靠性的新方法

为了从经受中子辐射过的小样品中获得更多的信息,提高监测试验的可靠性,对断裂韧性试验用过的试样加以二次开发利用具有重要意义。本研究对断裂韧性辐射脆化监测试验用过的 Charpy尺寸试样进行重新设计和利用,从1个试样只能得到1—3个断裂韧性试验数据提高到9个数据,从而显著改善和提高核压力容器中子辐射脆化断裂韧性监测试验和评定的可靠性。同时,对影响预制疲劳裂纹深侧槽 Charpy 尺寸复合试样合理设计的诸因素进行了探讨。     

Prediction of lower bound fracture toughness for lifetime evaluation of reactor pressure vessels

The potential damage of embrittlement in service is a very important problem of MnMoNi steels used for the nuclear reactor pressure vessel. A decrease of critical flaw size may occur when embrittlement proceeds. The remaining lifetime of the reactors should be assessed taking into account the embrittlement of the steel paying special attention to the degradation of dynamic fracture toughness. The present study introduces the basic concept of the remaining lifetime assessment. Examined was a small specimen fracture toughness test for measuring the dynamic fracture toughness of nuclear reactor pressure vessel (RPV) steels. The result was applied in the measurement of the dynamic fracture toughness of 12 heats of RPV steels. The test results were analyzed to find more practical applications and a method is presented to predict the lower bound dynamic fracture toughness using the Charpy impact test and tensile test results.     

On the dynamic fracture toughness and crack tip strain behavior of nuclear pressure vessel steel: Application of electromagnetic force

This paper is concerned with the application of the electromagnetic force to the determination of the dynamic fracture toughness of materials. Taken is an edge-cracked specimen which carries a transient electric current I and is simply supported in a steady magnetic field B. As a result of their interaction, the dynamic electromagnetic force occurs in the whole body of the specimen, which is then deformed to fracture in the opening mode of cracking.Using the electric potential and the J - R curve methods to determine the dynamic crack initiation point in the experiment, together with the finite element method to calculate the extended J-integral with the effects of the electromagnetic force and inertia, the dynamic fracture toughness values of nuclear pressure vessel steel A508 class 3 are evaluated over a wide temperature range from lower to upper shelves.The strain distribution near the crack tip in the dynamic process of fracture is also obtained by applying a computer picture processing.     

Beremin模型预测尺寸效应对A508-3钢断裂韧性的影响

断裂韧性是用于表征反应堆压力容器（RPV）钢脆性状态的重要指标。在开展相关研究时,由于辐照空间小等原因,一般采用小尺寸紧凑拉伸（CT）试样。为掌握CT试样尺寸变化对国产RPV钢断裂韧性测试结果的影响,对国产A508-3钢的不同尺寸CT试样进行了测试分析,采用Beremin模型方法研究了尺寸效应对断裂韧性数据的影响,并建立了不同尺寸CT试样的断裂韧性数据归一化模型（TSM）。结果表明,同一温度下实验测得的断裂韧性值随试样尺寸的减小逐渐增大,不同样品通过标准方法得到的归一化数据存在偏差,本文建立的TSM可有效减小换算数据偏差。     

核电站压力容器用A508CL3钢及其窄间隙埋弧焊焊缝的JR阻力曲线

材料的ＪＲ阻力曲线是核工程结构断裂过程的稳定性和失效评定的重要基础。本研究采用美国ＡＳＴＭＥ８１３标准和国家标准ＧＢ２０３８－８０测定了核电站压力容器用Ａ５０８ＣＬ３钢及其窄间隙埋弧焊焊缝的ＪＲ阻力曲线，并研究了试样尺寸对ＪＲ阻力曲线的影响。     

A new technique for detection of dynamic crack initiation

A new test device was constructed to measure dynamic fracture toughness using electromagnetic force as a dynamic load and a laser system for the detection of load-line deflection. This method provides several advantages with respect to load control, high strain rate and easy instrumentation of the test device.Using the device, experiments on the dynamic fracture were performed with use of edge-cracked three point bending specimens which were made from the nuclear pressure vessel material A508cl.3.The present paper reports on the characteristic feature of dynamic fracture, the measuring technique of dynamic loading and deflection, the detection of dynamic crack initiation and fractographic observation.The detection of the dynamic crack initiation was made possible by the application of an AC electrical potential method that employs a lock-in amplifier driven by a demodulation mode of signal averager and guarantees a fast response to the crack initiation.It was found that the fracture was initiated after unloading of the electromagnetic force is finished, in other words, the fracture was caused by an inertia force and the dynamic fracture toughness J_Id of the test material was elevated with the increasing loading rate.     

Estimation of fracture toughness of 20MnMoNi55 steel in the ductile to brittle transition region using master curve method

Fracture toughness is an important material property to assess the critical load for structural integrity of reactor pressure vessel steel. In this paper, master curve method proposed by Kim Wallin is used to estimate the fracture toughness of 20MnMoNi55 steel in the ductile to brittle transition regime. Reference temperature (T₀) is evaluated using both single temperature and multi-temperature method for one inch thick compact tension (1T-CT) specimens. Reference temperature (T₀) is also determined from Charpy V-notch test data and compared. Effect of selection of temperature range and number of test temperatures on the value of T₀ is also studied. It is observed that Charpy test results yield lower values of unirradiated T₀ compared to 1T-CT specimen tests. It is also observed that most of the fracture toughness values fall between 5% and 95% boundary of fracture toughness curves for all the evaluations.     

Heavy-section steel technology program: Intermediate-scale pressure vessel tests

Eight flawed 990-mm-OD, 152-mm-thick vessels of ASTM A508 class 2 forging steel or A533, grade B, class 1 steel plate have been pressurized hydraulically to burst or rupture. The rupture test of one vessel (V-7) was repeated pneumatically to study the effects of the sustained load thus attainable. Test temperatures ranged from 0 to 91°C so that transitional to upper shelf fracture toughness behavior was observed. Pretest predictions of failure pressure were based on tensile and toughness properties determined from Charpy-size to 102-mm-thick specimens representative of the test vessels. Linear elastic fracture mechanics based on strain and plastic instability analyses were generally adequate for determining the failure pressure, which ranged from 2.15 to 3.28 times design pressure.