Effects of Neutron, Ion and Proton Irradiation on Nano-Indentation Hardness of RPV Steels

2020 ◽  
Vol 999 ◽  
pp. 39-46
Author(s):  
Cheng Liang Li ◽  
Guo Gang Shu ◽  
Jing Li Yan ◽  
Wei Liu ◽  
Yuan Gang Duan
Keyword(s):  
Proton Irradiation ◽  
Indentation Hardness ◽  
Irradiation Embrittlement ◽  
Irradiation Hardening ◽  
Nano Indentation ◽  
Rpv Steel ◽  
Hardness Tests ◽  
Increase Rate ◽  
Before And After ◽  
Reactor Pressure

The irradiation embrittlement damage of reactor pressure vessel (RPV) steel is one of its primary failure mechanisms. In this work, neutron, ion and proton irradiation experiments were carried on the same commercial RPV steels with the same irradiation fluence under the same temperature of 292°C. Then the nano-indentation hardness tests were performed on the RPV steel before and after irradiation. The results show that the irradiation hardening effects are observed by means of nano-indentation technique under the above three irradiations, and the hardening features are basically the same. While the max variation and increase rate are obviously different between those irradiations. It is found that the main reason of the above differences are caused by different energies of irradiation energetic particles, resulting in different types and quantities of defects. The conclusions in this paper are helpful to select and compare different irradiation experiments to the research of RPV steels irradiation embrittlement damage.

Effects of Neutron Irradiation on the Mechanical and Electromagnetic Properties of Reactor Pressure Vessel Steels

2017 ◽  
Author(s):  
Li Chengliang ◽  
Shu Guogang ◽  
Chen Jun ◽  
Liu Yi ◽  
Liu Wei ◽  
...  
Keyword(s):  
Neutron Irradiation ◽  
Pressure Vessel ◽  
Power Plants ◽  
Hysteresis Loops ◽  
Reactor Pressure Vessel ◽  
Electromagnetic Properties ◽  
Irradiation Damage ◽  
Indentation Hardness ◽  
Rpv Steel ◽  
Reactor Pressure

The effect of neutron irradiation damage of reactor pressure vessel (RPV) steels is a main failure mode. Accelerated neutron irradiation experiments at 292 °C were conducted on RPV steels, followed by testing of the mechanical, electrical and magnetic properties for both the unirradiated and irradiated steels in a hot laboratory. The results showed that a significant increase in the strength, an obvious decrease in toughness, a corresponding increase in resistivity, and the clockwise turn of the hysteresis loops, resulting in a slight decrease in saturation magnetization when the RPV steel irradiation damage reached 0.0409 dpa; at the same time, the variation rate of the resistivity between the irradiated and unirradiated RPV steels shows good agreement with the variation rates of the mechanical properties parameters, such as nano-indentation hardness, ultimate tensile strength, yield strength at 0.2% offset, upper shelf energy and reference nil ductility transition temperature. Thus, as a complement to destructive mechanical testing, the resistivity variation can be used as a potentially non-destructive evaluation technique for the monitoring of the RPV steel irradiation damage of operational nuclear power plants.

Measuring Microscopic Properties of a Single-Crystalline Diamond by Nano-Indentation Technology

2015 ◽  
Vol 1120-1121 ◽  
pp. 378-382 ◽  
Author(s):  
Qi Long Wei ◽  
Xiao Bin Yue ◽  
Xiao Yuan Li ◽  
Bo Liu ◽  
Xiao Feng Zhang ◽  
...  
Keyword(s):  
Great Influence ◽  
Fused Silica ◽  
Diamond Surface ◽  
Measurement Properties ◽  
Indentation Hardness ◽  
Silica Sample ◽  
Single Crystalline ◽  
Nano Indentation ◽  
Indentation Force ◽  
Before And After

Nano-indentation technology was brought to study microscopic mechanical properties of a single-crystalline diamond (SCD). Nano-indentation measurement was conducted on the {100} plane of SCD, and influences of various factors on measured results were analyzed, from which methods were confirmed to improve veracity of measurement. Properties of the indenter were checked with a fused silica sample both before and after indentation on diamond, which provided guarantee to veracity of results on diamond. It was found that tilt of diamond surface had so great influence that it could damage the indenter, and make the indentation curves anomalous. While damage of indenter could be avoided and valid measurement results could be obtained when tilt of diamondsurface was decreased below 0.10º and the maximal indentation force was less than 10 mN. Deformation of the diamond was almost full-elastic during indentation process. Indentation hardness of {100} plane of the SCD was about 70 GPa with standard deviation less than 3 GPa. And there had good reproducibility between two groups of measurements.

Study on Irradiation Damage of RPV Steels Based on Coupling Cluster Dynamics and Crystal Plasticity Finite Element Method

2020 ◽  
Author(s):  
Xiaotong Wang ◽  
Ying Luo ◽  
Yuanyuan Dong ◽  
Weihua Yao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Crystal Plasticity ◽  
Pressure Vessel ◽  
Irradiation Damage ◽  
Irradiation Hardening ◽  
Crystal Plasticity Finite Element ◽  
Rpv Steel ◽  
Reactor Pressure ◽  
Element Method

Abstract Irradiation hardening is one of the most important aging effects of reactor pressure vessel (RPV) steel in long-term service. A number of studies have indicated that irradiation hardening is mainly caused by irradiation induced defects, such as dislocation loops and precipitates. In this paper, we have simulated the irradiation damage of low-copper reactor pressure vessel (RPV) steel. The generation of Mn-Ni-Si precipitates is simulated by the cluster dynamics model based on rate theory. On this basis, the crystal plasticity finite element method based on modified crystal plasticity model is used to simulate the effect of Mn-Ni-Si precipitates on the mechanical properties of RPV steels. The simulated results has been compared with the experimental results from the literature. By coupling the cluster dynamics and the crystal plastic finite element method, we suggest a multi-scale simulation method to simulate and predict irradiation damage of RPV steel.

Prediction of Irradiation Embrittlement for Chinese Domestic A508-3 Steel

2010 ◽  
Author(s):  
Feng Lu ◽  
Rongshan Wang ◽  
Ping Huang ◽  
Haiyang Qian
Keyword(s):  
Nuclear Power ◽  
Surveillance Program ◽  
Primary Concern ◽  
Regulatory Requirements ◽  
Irradiation Embrittlement ◽  
Safety Standards ◽  
Rpv Steel ◽  
The Us ◽  
Calculation Results ◽  
Reactor Pressure

Reactor Pressure Vessel (RPV) is one of the most important components in nuclear power plant (NPP). The aging mechanism of primary concern for RPV is irradiation embrittlement, which can result in a decrease of fracture toughness of RPV steel. Prediction of irradiation embrittlement for a certain Chinese domestic manufactured A508-3 steel is performed. The calculation results given by the US safety standards, the French RCC-M standards and other international safety standards are compared with each other and compared to the data from commercial operation NPP surveillance program. The effect of neutron fluence is also investigated. Furthermore, the property of the steel against irradiation embrittlement is evaluated with the regulatory requirements in the relevant standards. It can be predicted that the Chinese domestic steel satisfies the requirements in these standards.

Toughness and Embrittlement of RPV Steels Using Ultrasonic Measurements

2004 ◽  
Author(s):  
Allen L. Hiser
Keyword(s):  
Fracture Toughness ◽  
Pressure Vessel ◽  
Ultrasonic Attenuation ◽  
Reactor Pressure Vessel ◽  
Irradiation Embrittlement ◽  
Nondestructive Determination ◽  
Rpv Steel ◽  
Suitable Parameter ◽  
Reactor Pressure

Neutron bombardment of reactor pressure vessel (RPV) steels causes reductions in fracture toughness in these steels, termed neutron irradiation embrittlement. Currently there are no accepted methods for nondestructive determination of the extent of the irradiation embrittlement nor the actual fracture toughness of the reactor pressure vessel. This paper summarizes the findings from an effort addressing the use of ultrasonic attenuation as a suitable parameter for nondestructive determination of irradiation embrittlement in RPV steels. The materials examined in this study include one heat of RPV steel that was heat treated to induce changes in its fracture toughness, several heats of RPV steel irradiated to assess neutron embrittlement changes in fracture toughness, and a matrix of RPV steels (in the unirradiated condition) with a range of as-fabricated fracture toughness levels.

scholarly journals Irradiation Hardening Behavior of He-Irradiated V–Cr–Ti Alloys with Low Ti Addition

2020 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Ken-ichi Fukumoto ◽  
Yoshiki Kitamura ◽  
Shuichiro Miura ◽  
Kouji Fujita ◽  
Ryoya Ishigami ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
Optimum Composition ◽  
Solid Solution Hardening ◽  
Irradiation Hardening ◽  
Hardening Behavior ◽  
Ti Alloys ◽  
Void Swelling ◽  
Before And After ◽  
Cr Addition ◽  
Ti Addition

A set of V–(4–8)Cr–(0–4)Ti alloys was fabricated to survey an optimum composition to reduce the radioactivity of V–Cr–Ti alloys. These alloys were subjected to nano-indenter tests before and after 2-MeV He-ion irradiation at 500 °C and 700 °C with 0.5 dpa at peak damage to investigate the effect of Cr and Ti addition and gas impurities for irradiation hardening behavior in V–Cr–Ti alloys. Cr and Ti addition to V–Cr–Ti alloys for solid–solution hardening remains small in the unirradiated V–(4–8)Cr–(0–4)Ti alloys. Irradiation hardening occurred for all V–Cr–Ti alloys. The V–4Cr–1Ti alloy shows the highest irradiation hardening among all V–Cr–Ti alloys and the gas impurity was enhanced to increase the irradiation hardening. These results may arise from the formation of Ti(CON) precipitate that was produced by He-ion irradiation. Irradiation hardening of V–Cr–1Ti did not depend significantly on Cr addition. Consequently, for irradiation hardening and void-swelling suppression, the optimum composition of V–Cr–Ti alloys for structural materials of fusion reactor engineering is proposed to be a highly purified V–(6–8)Cr–2Ti alloy.

Verification of Warm Prestressing Effect Under a Pressurized Thermal Shock (PTS) Event

1994 ◽  
Vol 116 (3) ◽  
pp. 267-273 ◽  
Author(s):  
H. Okamura ◽  
G. Yagawa ◽  
T. Hidaka ◽  
Y. Urabe ◽  
M. Satoh ◽  
...  
Keyword(s):  
Vessel Wall ◽  
Irradiation Embrittlement ◽  
Predictive Equations ◽  
Warm Prestressing ◽  
Pressurized Thermal Shock ◽  
Reactor Steels ◽  
Fracture Tests ◽  
Integrity Analysis ◽  
Temperature Margin ◽  
Reactor Pressure

Fracture tests for the verification of WPS (warm prestressing) effect were carried out by using large flat specimens and big compact specimens with low toughness. In the case of monotonical KI increasing during cooling, the specimen broke within the scatter band of KIC. On the other hand, when KI was decreasing during cooling, the specimens did not break even if KI values were beyond the scatter band of KIC. That is, WPS effect was confirmed even for the low toughness steel like reactor pressure vessel wall under neutron irradiation. Also, KI values at fracture can be predicted by Chell’s theory. By applying WPS effect and the predictive equations for irradiation embrittlement for Japanese PWR reactor steels to the PTS integrity analysis, much more temperature margin can be expected.

Noise behavior of semi-insulating GaAs particle detectors before and after proton irradiation

1999 ◽  
Vol 78 (1-3) ◽  
pp. 527-532 ◽  
Author(s):  
U. Biggeri ◽  
C. Canali ◽  
C. Lanzieri ◽  
C. Leroy ◽  
F. Nava ◽  
...  
Keyword(s):  
Proton Irradiation ◽  
Particle Detectors ◽  
Before And After

Verification of Probabilistic Fracture Mechanics Analysis Code for Reactor Pressure Vessel

2021 ◽  
Vol 143 (4) ◽  
Author(s):  
Yinsheng Li ◽  
Genshichiro Katsumata ◽  
Koichi Masaki ◽  
Shotaro Hayashi ◽  
Yu Itabashi ◽  
...  
Keyword(s):  
Fracture Mechanics ◽  
Working Group ◽  
Power Plants ◽  
Structural Integrity ◽  
Pressure Vessels ◽  
Irradiation Embrittlement ◽  
Energy Agency ◽  
Probabilistic Fracture Mechanics ◽  
Integrity Assessments ◽  
Reactor Pressure

Abstract Nowadays, it has been recognized that probabilistic fracture mechanics (PFM) is a promising methodology in structural integrity assessments of aged pressure boundary components of nuclear power plants, because it can rationally represent the influencing parameters in their inherent probabilistic distributions without over conservativeness. A PFM analysis code PFM analysis of structural components in aging light water reactor (PASCAL) has been developed by the Japan Atomic Energy Agency to evaluate the through-wall cracking frequencies of domestic reactor pressure vessels (RPVs) considering neutron irradiation embrittlement and pressurized thermal shock (PTS) transients. In addition, efforts have been made to strengthen the applicability of PASCAL to structural integrity assessments of domestic RPVs against nonductile fracture. A series of activities has been performed to verify the applicability of PASCAL. As a part of the verification activities, a working group was established with seven organizations from industry, universities, and institutes voluntarily participating as members. Through one-year activities, the applicability of PASCAL for structural integrity assessments of domestic RPVs was confirmed with great confidence. This paper presents the details of the verification activities of the working group, including the verification plan, approaches, and results.

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