9%～11%Cr锅炉用耐热钢在蒸汽中的氧化行为

Oxidation behavior of 9%-11% Cr heat resistant boiler steels in steam

电站锅炉用钢长期处于高温高压的工作环境下,材料在超临界水中的抗蒸汽腐蚀性能是衡量其服役性能的一个重要指标。以Cr的质量分数为11%的钢为研究对象,在蒸汽氧化试验平台上完成了对试验钢的蒸汽腐蚀试验,通过数值模拟获得了氧化动力学曲线。结果表明,试验钢的氧化增重符合抛物线规律。通过SEM、XRD等方法分析了氧化层的形貌、化学成分,结果表明,氧化层为双层结构。对比分析了Cr的质量分数为9%和11%的钢后发现,增加Cr含量明显提高了抗蒸汽氧化性能。

Boiler steels for power plant usually work in severe environment with high temperature and high pressure for a long time. The corrosion behaviors of boiler steels exposed to supercritical water are very important. A steel with mass fraction of Cr of 11% was researched by means of a steam oxidation experiment platform. The oxidation kinetic curve of the experimental steel was obtained by mathematics simulation. It shows that the oxidation kinet- ics of the experimental steel follows parabolic equation. Morphology and chemical composition of oxidation layer were analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction respec- tively. The oxidation layer consists of two layers. Compared with a steel with mass fraction of Cr of 9%, the experiment results show that the increase of Cr content promotes the oxidation resistance of steel obviously.