630℃超超临界发电机组水冷壁T91耐热钢高温腐蚀行为及机理研究

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中图分类号：TG132 文献标志码：ADOI： 10.7652/xjtuxb202605013 文章编号：0253-987X（2026）05-0131-11

Abstract： To investigate the high-temperature corrosion behavior of heat-resistant steel，T91 ferritic heat-resistant steel，which is used in the water-cooled walls of 630∘C ultra-supercritical power generation units，is selected as the research subject. The flue gas corrosion behavior of the heat-resistant steel under different load operating conditions was studied. An analytical balance was used to measure the mass change of the steel before and after corrosion， while scanning electron microscopy and X-ray difraction were employed to characterize the morphology， composition，and distribution of the corrosion products. The experimental results indicate that the corrosion kinetic curve of T9l heat-resistant steel at 500∘C follows a parabolic pattern. At 550∘C and 600∘C ， the corrosion kinetic curves initially follow a parabolic pattern but transition to a linear pattern after 100 hours and 75 hours，respectively. At 600∘C ，the slope of the linear portion increases， indicating that temperature accelerates the transition in the corrosion behavior of the heat-resistant steel. The surfaces of the heat-resistant steel exhibit reddish-brown color，with the surface morphology transitioning from filamentous to spinel-like and spherical corrosion products. The corrosion products on the surface of T91 heat-resistant steel present a three-layer structure，from the gas side to the substrate side： an Fe-O corrosion layer （mainly Fe3O4 and Fe2O3 ），an FeS corrosion layer，and an Fe-Cr-O corrosion layer （ （FeCr2O4） ）. As the temperature increases，the thickness of the corrosion layers grows，with a 42.9% increase in oxide layer thickness for every 100∘C rise in temperature. The growth mechanism of the corrosion layers shift from being dominated by outward diffusion of cations to being dominated by inward diffusion of anions. This transition leads to the formation of defects such as pores and sulfides at the oxide/substrate interface， increasing the risk of failure in power plant boiler water-cooled walls.

Keywords： heat-resistant steel; high temperature; corrosion behavior; flue gas

随着超超临界发电技术中工质温度、压力不断升高[1-3]，电站锅炉水冷壁、过热器与再热器的壁面温度持续上升[4-6]，对耐热材料的高温强度及耐腐蚀性能提出了更为严格的要求。（剩余17462字）