基于团簇动力学的低铜RPV用钢辐照产生析出相数值模拟研究

Numerical Simulation of Irradiation Induced Precipitates in Low Copper RPV Steels Based on Cluster Dynamics

反应堆压力容器(RPV)用钢在辐照后产生的基体损伤、溶质原子析出相等辐照缺陷,是造成其辐照脆化的主要原因。基于反应速率理论建立了考虑多种析出相形核机理的团簇动力学模型,模拟了低铜RPV用钢中Mn-Ni-Si析出相等辐照缺陷的产生及其尺寸、数密度随损伤剂量的变化。与实验数据的对比分析表明,同时考虑间隙原子型位错环主导和空位团簇主导这两种析出相形核机理的团簇动力学模型可以更好地模拟材料的辐照损伤行为。在此基础上辐照参数的敏感性分析表明,中子注量率对析出相的影响与注量有关,注量率越大,在低注量时产生的析出相越少,而在高注量时相对越多;此外,辐照温度越低越易产生析出相。

Irradiation induced defects such as matrix damage and solute atom precipitates are the main causes of irradiation embrittlement.Based on the reaction rate theory,a cluster dynamics model considering multiple nucleation mechanisms of Mn-Ni-Si precipitates is established,and the generation of irradiation induced defects,the irradiation dose dependence of mean size,number density of Mn-Ni-Si precipitates and dislocation loops in low-copper RPV steels are simulated.The comparative analysis with experimental data shows that the modified cluster dynamics model considering both the precipitates formation mechanism of interstitial dislocation loops domination and vacancy cluster domination can better simulate the irradiation damage behavior of materials.On this basis,the sensitivity analysis of the irradiation parameters shows that the effect of the neutron flux on the irradiation induced precipitates is related to the neutron fluence,the larger the irradiation flux is,the less the precipitates will be generated at low fluence,and the more the precipitates will be at high fluence.Further more,the precipitates is more likely to be produced at lower temperature.