超临界水工况下铁素体马氏体钢氧化速率常数的计算方法与分析

摘要

Based on an available space model of duplex oxide scale,the oxidation rates of two ferritic-martensitic steels were predicted in the environment of supercritical water at 400 ℃,500 ℃ and 600 ℃,while the diffusion coefficients of iron in magnetite and Fe-Cr spinel were extrapolated at relatively low temperatures.Results show that the oxygen partial pressure at the magnetite/supercritical water interface meets the requirement of reaction equilibrium on equivalent oxygen partial pressure.The oxidation simulation results of NF616 steel at 500 ℃ and 600 ℃ and of HCM12A steel at 600 ℃ are found to be close to the experimental data,indicating that the consumption is basically effective.The relative error of HCM12A steel at both 400 ℃ and 500 ℃ between oxidation simulation and actual measurements is 40％,and its oxidation rate is less than that of EPRI by 1-2 orders of magnitude.%基于双层氧化皮的可用空间模型,预测了400℃、500℃和600℃时超临界水环境下2种铁素体马氏体钢的氧化速率,并推算了较低温度下Fe在磁铁矿和铁铬尖晶石层中的扩散系数.结果表明:磁铁矿/超临界水界面处的氧分压满足反应平衡的等效氧分压;NF616钢(500℃、600℃)和HCM12A钢(600℃)的氧化皮增重模拟值与实验值较接近,说明基本假设是有效的;在400℃、500℃条件下HCM12A钢氧化皮增重的模拟值与实验值误差为40％,氧化速率比EPRI的氧化速率低1～2个数量级.