核燃料棒包壳腐蚀对格架磨蚀的影响研究

Study of the Effect of Cladding Corrosion on Grid Fretting Wear

锆合金包壳在高温高压水中会发生均匀腐蚀,金属基体表面不断生成氧化膜,氧化膜硬度大,会对格架磨蚀过程产生影响。研究氧化锆不同晶体结构的磨蚀性质,结合锆合金腐蚀演化过程完善了多时期磨蚀计算模型,分析包壳腐蚀对磨蚀试验中磨蚀系数测量的影响。基于平面接触假设推导磨蚀系数随磨蚀深度的变化关系,结合多时期磨蚀模型和燃料棒线性振动分析方法,计算燃料棒包壳在反应堆运行寿期内的最大磨蚀深度。不同格架在不同初始夹持力条件下的最大磨蚀深度计算结果表明预磨蚀期包壳腐蚀对初始夹持力足够大的格架磨蚀有抑制作用。

With the uniform corrosion of zirconium alloys cladding in high temperature and high pressure coolant,the oxide films are generated on the surface of base-metal,which are harder than the zirconium and have effect on the grid wear process.By studying the wear properties of the different zirconia crystals,and combining the corrosion evolution process of zirconium alloy,a multi-stage wear model was improved and the effect of cladding corrosion on wear coefficient measurement experiment can be analyzed.The relationship between the wear coefficient and wear depth derived from the assumption of plane contact,and the multi-stage wear model and linear vibration method can be used to calculate the maximum wear depth of the fuel rod cladding in reactor operation life.The results of wear depth at different grids with different initial normal forces showed that the cladding corrosion in pre-wear period can restrain the grid wear when the initial normal force was large enough.