示范快堆中间热交换器材料316H钢钠中老化行为研究

Research on the Aging Behavior of 316H Steel Sodium for Intermediate Heat Exchangers of Demonstration Fast Reactors in Sodium

316H钢是中国示范快堆中间热交换器的主要材料,随着运行时间的增加,其老化效应不断累积。为探索316H钢在示范快堆中间热交换器运行工况下的老化行为,此研究分别在353℃和535℃静态钠条件下对316H钢管材和板材试样进行了1000~8000 h的相容性试验,并对试验后的样品开展微观表征、腐蚀速率测量以及力学性能测试等分析。结果显示:353℃条件下试样几乎不发生腐蚀现象,而在535℃条件下,高温加速了扩散使得材料的老化行为显著,随着试验时间的增加,材料在钠中的腐蚀转为稳态阶段。研究表明:316H钢在钠中的老化行为受到钠的温度、浸泡时间以及材料制造工艺等因素影响,在低氧低碳的低温钠环境中有较好的抗老化能力,在温度相对较高、时间较长的钠环境中存在老化迹象。

316H steel is the main material for the intermediate heat exchangers of China's demonstration fast reactors.With the increase of operating time,its aging effect continues to accumulate.To explore the aging behavior of 316H steel under the operating conditions of the intermediate heat exchangers of demonstration fast reactors,this study conducted the compatibility test of 316H steel pipe and plate specimens for 1000-8000 h under the static sodium conditions of 353℃and 535℃,and analyzed the microstructure characterization,corrosion rate measurement and mechanical property test of the samples after the test.The results showed that there was almost no corrosion phenomenon on the samples under the condition of 353℃,and that under the condition of 535℃,high temperature accelerated diffusion,resulting in the significant aging behavior of the material,and the corrosion of the material in sodium shifted to a steady-state stage with the increase of test time.The research shows that the aging behavior of 316H steel in sodium is affected by factors such as the temperature of sodium,soak time and the manufacturing process of the material,and that it has good anti-aging ability in the low-oxygen,low-carbon and low-temperature sodium environment and has the sign of aging in the relatively high-temperature and long-time sodium environment.