CN-115795226-B - Method for determining environmental damage coefficient and designing fatigue life under high-temperature lead bismuth environment

CN115795226BCN 115795226 BCN115795226 BCN 115795226BCN-115795226-B

Abstract

The invention relates to a method for determining an environmental damage coefficient and designing fatigue life in a high-temperature lead bismuth environment. The method comprises the steps of performing fatigue tests on a component in a room-temperature air environment and different lead-bismuth environments respectively to obtain fatigue test data in the different environments, establishing a room-temperature air environment life prediction model according to the fatigue test data in the room-temperature air environment, determining a lead-bismuth environment damage coefficient according to the fatigue test data in the different lead-bismuth environments, bringing the lead-bismuth environment damage coefficient into the air environment life prediction model, establishing a life prediction model considering the influence of the lead-bismuth environment, and determining a fatigue curve considering the influence of the lead-bismuth environment according to the life prediction model considering the influence of the lead-bismuth environment, wherein the fatigue curve considering the influence of the lead-bismuth environment is used for evaluating the environmental damage of the component in the lead-bismuth environment. The method can realize accurate evaluation of the component environmental damage under the lead bismuth environment.

Inventors

TAN JIANPING
PENG CUILING
RONG GANG
YANG YI
LIN XINPENG
HE DECHENG
WANG RUNZI
ZHANG XIANCHENG
NIE WENRUI
TU SHANDONG
ZHU HE
WANG JI
WANG XIAOWEI

Assignees

华东理工大学
中广核研究院有限公司

Dates

Publication Date: 20260505
Application Date: 20220906

Claims (5)

1. The method for determining the environmental damage coefficient and designing the fatigue life in the high-temperature lead bismuth environment is characterized by comprising the following steps: Respectively carrying out fatigue tests on the component in a room temperature air environment and different lead bismuth environments to obtain fatigue test data in the room temperature air environment and fatigue test data in different lead bismuth environments; Establishing a room temperature air environment life prediction model according to the fatigue test data in the room temperature air environment; According to the fatigue test data under different lead bismuth environments, determining the lead bismuth environment damage coefficient specifically comprises the following steps: Setting a temperature extrapolation factor and a strain rate extrapolation factor; Taking 350 ℃ as a calibration temperature of the lead bismuth environment, and acquiring the fatigue life of the lead bismuth environment at room temperature, the fatigue life of the lead bismuth environment at the calibration temperature, the fatigue life of the lead bismuth environment at different temperatures and the lead bismuth environment damage coefficient at the calibration temperature; Determining a first ratio of the fatigue life of the room temperature air environment to the fatigue life of the lead bismuth environment under different oxygen concentrations under the same strain amplitude according to the fatigue life of the room temperature air environment and the fatigue life of the lead bismuth environment under the calibrated temperature; respectively solving high oxygen concentration and low oxygen concentration by using the first ratio, and determining a power exponent relation between the first ratio and a strain amplitude; Determining a second ratio of the fatigue life of the lead-bismuth environment at different temperatures under the same strain amplitude according to the fatigue life of the lead-bismuth environment at the calibrated temperature and the fatigue life of the lead-bismuth environment at the different temperatures; Calculating and determining the lead bismuth environmental damage coefficient at the temperature according to the lead bismuth environmental damage coefficient at the calibration temperature and the second ratio; determining the lead-bismuth environment damage coefficients at different temperatures according to the lead-bismuth environment damage coefficients at the determined temperatures and the power exponent relationship, wherein the lead-bismuth environment damage coefficients comprise the lead-bismuth environment damage coefficients at different temperatures and the lead-bismuth environment damage coefficients at different strain rates at the determined temperatures; The lead bismuth environment damage coefficient is brought into an air environment life prediction model, a life prediction model considering the lead bismuth environment influence is established, and the life prediction model considering the lead bismuth environment influence is as follows: ; Wherein, the The lead bismuth environment fatigue life is that of lead bismuth under any condition; F LBE is the environmental damage coefficient of lead bismuth; And determining a fatigue curve considering the lead-bismuth environmental influence according to the life prediction model considering the lead-bismuth environmental influence, wherein the fatigue curve considering the lead-bismuth environmental influence is used for evaluating the environmental damage of the component in the lead-bismuth environment.
2. The method for determining environmental damage coefficient and designing fatigue life in high temperature lead bismuth environment according to claim 1, wherein the strain amplitude of the fatigue test in room temperature air environment is in the range of 0.2% to 2%; The oxygen concentration interval of the fatigue test under different lead-bismuth environments is divided into high oxygen and low oxygen, the test temperature range is 150 ℃ to 450 ℃, and the test strain rate range is /S to /s。
3. The method for determining environmental damage coefficient and designing fatigue life in high-temperature lead bismuth environment according to claim 1, wherein the function relation between strain and life in the room-temperature air environmental life prediction model is: ; Wherein, the A is an equation coefficient; The fatigue life is represented by b being a first material constant and c being a second material constant.
4. The method for determining the environmental damage coefficient and designing the fatigue life under the high-temperature lead-bismuth environment according to claim 1, wherein the determining the lead-bismuth environmental damage coefficient according to the fatigue test data under the different lead-bismuth environments specifically comprises: Obtaining the lead bismuth environment fatigue life under the calibration strain rate, the lead bismuth environment damage coefficient under the calibration strain rate and the lead bismuth environment fatigue life under different strain rates; Determining a third ratio of the lead bismuth environmental fatigue life at the nominal strain rate to the lead bismuth environmental fatigue life at the different strain rates; Calculating and determining the lead bismuth environment damage coefficient under the strain rate according to the third ratio and the lead bismuth environment damage coefficient under the calibrated strain rate; And calculating the lead bismuth environment damage coefficients of different strain rates at the determined temperature according to the lead bismuth environment damage coefficients of the determined strain rate.
5. The system for determining an environmental damage coefficient and designing a fatigue life in a high-temperature lead bismuth environment is characterized in that the system for determining an environmental damage coefficient and designing a fatigue life in a high-temperature lead bismuth environment performs the method for determining an environmental damage coefficient and designing a fatigue life in a high-temperature lead bismuth environment according to any one of claims 1 to 4, and the system for determining an environmental damage coefficient and designing a fatigue life in a high-temperature lead bismuth environment comprises: the fatigue test data acquisition module is used for carrying out fatigue tests on the component in a room-temperature air environment and different lead-bismuth environments respectively to acquire fatigue test data in the room-temperature air environment and fatigue test data in different lead-bismuth environments; The room temperature air environment life prediction model building module is used for building a room temperature air environment life prediction model according to fatigue test data in the room temperature air environment; The lead bismuth environment damage coefficient determining module is used for determining lead bismuth environment damage coefficients according to the fatigue test data under different lead bismuth environments, wherein the lead bismuth environment damage coefficients comprise lead bismuth environment damage coefficients under different temperatures and lead bismuth environment damage coefficients with different strain rates under the determined temperatures; The service life prediction model building module is used for taking the lead bismuth environment damage coefficient into an air environment service life prediction model to build a service life prediction model taking the lead bismuth environment influence into consideration; The fatigue curve determining module is used for determining a fatigue curve considering the lead-bismuth environmental influence according to the life prediction model considering the lead-bismuth environmental influence, and the fatigue curve considering the lead-bismuth environmental influence is used for evaluating the environmental damage of the component in the lead-bismuth environment.

Description

Method for determining environmental damage coefficient and designing fatigue life under high-temperature lead bismuth environment Technical Field The invention relates to the field of fatigue design, in particular to a method for determining an environmental damage coefficient and designing fatigue life in a high-temperature lead bismuth environment. Background Nuclear energy is generally considered as a clean, safe and efficient energy source, has the potential of replacing petroleum and gas energy sources and plays an important role in the current world energy structure. Because the existing three-generation nuclear reactor has the problems of low resource utilization rate, radioactive waste accumulation, nuclear safety and the like, the fourth generation reactor adopting the technical route of 'thermal reactor-fast reactor-fusion reactor' will become the main trend of the future nuclear energy development. In the fourth generation nuclear reactor, the lead bismuth fast cooling reactor is widely valued at home and abroad because of good safety and neutron economy. However, due to the wettability and corrosiveness of the lead and bismuth and the structural composition of the metal material, the material degradation phenomena such as liquid metal corrosion and liquid metal embrittlement can occur when the metal contacts the lead and bismuth environment for a long time, which severely restricts the development of the lead and bismuth reactor. The existing high-temperature fatigue design curve is obtained by a fatigue test under a high-temperature air environment, and the influence of complex environments such as lead bismuth on the fatigue life of the component is not considered, so that the establishment of a fatigue design method of the component under the lead bismuth environment is urgent. Disclosure of Invention The invention aims to provide an environment damage coefficient determination and fatigue life design method under a high-temperature lead-bismuth environment so as to realize accurate evaluation of component environment damage under the lead-bismuth environment. In order to achieve the above object, the present invention provides the following solutions: The method for determining the environmental damage coefficient and designing the fatigue life in the high-temperature lead bismuth environment comprises the following steps: Respectively carrying out fatigue tests on the component in a room temperature air environment and different lead bismuth environments to obtain fatigue test data in the room temperature air environment and fatigue test data in different lead bismuth environments; Establishing a room temperature air environment life prediction model according to the fatigue test data in the room temperature air environment; determining lead-bismuth environment damage coefficients according to the fatigue test data under different lead-bismuth environments, wherein the lead-bismuth environment damage coefficients comprise lead-bismuth environment damage coefficients under different temperatures and lead-bismuth environment damage coefficients with different strain rates under the determined temperatures; the lead bismuth environmental damage coefficient is brought into an air environmental life prediction model, and a life prediction model considering the influence of the lead bismuth environment is established; And determining a fatigue curve considering the lead-bismuth environmental influence according to the life prediction model considering the lead-bismuth environmental influence, wherein the fatigue curve considering the lead-bismuth environmental influence is used for evaluating the environmental damage of the component in the lead-bismuth environment. Optionally, the strain amplitude of the fatigue test in the room temperature air environment is in the range of 0.2% to 2%; The oxygen concentration interval of the fatigue test under different lead-bismuth environments is divided into high oxygen and low oxygen, the test temperature is in the range of 150 ℃ to 450 ℃, and the test strain rate is in the range of 5X 10 -6/s to 5X 10 -3/s. Optionally, the functional relationship between strain and life in the room temperature air environment life prediction model is: Wherein ε t is the total strain range, a is the equation coefficient, N f is the fatigue life, b is the first material constant, and c is the second material constant. Optionally, the determining the damage coefficient of the lead-bismuth environment according to the fatigue test data under the different lead-bismuth environments specifically includes: Setting a temperature extrapolation factor and a strain rate extrapolation factor; Taking 350 ℃ as a calibration temperature of the lead bismuth environment, and acquiring the fatigue life of the lead bismuth environment at room temperature, the fatigue life of the lead bismuth environment at the calibration temperature, the fatigue life of the lead bismuth environment at dif