高温含硼水蒸气中304不锈钢的腐蚀行为

Corrosion Behavior of 304 Stainless Steel in High Temperature Boron-containing Vapor

研究了304不锈钢在300℃含硼水蒸气中的腐蚀行为,采用扫描电镜及配套能谱仪(SEM-EDS)、X射线衍射(XRD)等表征手段,分析了试样在含硼水蒸气中腐蚀后表面的显微结构及成分分布,并与液相中试样对比。结果表明:气相中试样表面氧元素的质量分数显著高于液相试样,并且气相中试样表面形成的氧化膜为双层结构,上层为Fe_(2)O_(3)和Fe_(3)O_(4)颗粒层,下层为细密的含铬尖晶石层,而液相试样表面仅有一层分散的氧化物颗粒;当密闭反应器中有适量氧气时,可显著降低含硼水蒸气中304不锈钢的腐蚀程度,分析讨论了可能的腐蚀与防腐机理。

The corrosion behavior of 304 stainless steel in boron-containing water vapor at 300℃was studied.The microstructure and composition distribution of the surface of the sample after corrosion in boron-containing water vapor were analyzed by scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and X-ray diffraction(XRD).The results showed that the mass fraction of oxygen on the surface of the sample in the vapor phase was significantly higher than that in the liquid phase,and the oxide film formed on the surface of the sample in the vapor phase was a double-layer structure.The upper layer was a Fe2O_(3) and Fe3O_(4) particle layer,and the lower layer was a dense chromium-containing spinel layer,while there was only a layer of dispersed oxide particles on the surface of the liquid phase sample.When there was an appropriate amount of oxygen in the closed reactor,the corrosion degree of 304 stainless steel in boron-containing water vapor could be significantly reduced.The possible corrosion and anti-corrosion mechanisms were analyzed and discussed.