锅炉受热面复合陶瓷涂层抗高温SO2腐蚀性能

针对燃煤锅炉受热面存在的高温腐蚀问题，采用料浆法在20G钢材表面制备复合陶瓷涂层，烧结后的复合陶瓷涂层表面较为致密，涂层与基材具有良好的结合状态。对喷涂及未喷涂陶瓷涂层钢片在SO₂腐蚀气氛环境下的抗高温腐蚀性能进行试验，并采用热分析动力学方法对试验数据进行处理，结果表明，在400~500℃温度范围内，两种试样的腐蚀过程均符合一维扩散反应动力学模式，计算求得喷涂涂层钢片腐蚀反应活化能低于未喷涂涂层钢片，涂层具有较好的抗高温腐蚀性能。对腐蚀试验后试样的形貌、成分和物相分析结果显示，涂层在SO₂气氛下腐蚀后，表面生成K₂SO₄晶粒，但由于涂层较为致密，阻止了S的扩散，内部基本没有检测到K₂SO₄的存在。

SO2 corrosion resistance of composite ceramic coating for boiler heating surface

To address high-temperature corrosion at heating surface of coal-fired boilers, a composite ceramic coating on surface of 20G steel sheet was prepared by slurry method. After sintering, the composite ceramic coating had a relatively dense surface and good bonding to the substrate. Both uncoated and ceramic-coated steel sheets were studied for high-temperature corrosion resistance in sulfur dioxide (SO₂) by thermal kinetic analysis method. The results show that corrosion of the coated and uncoated steel sheets adheres to one dimensional diffusion reaction kinetic model at 400-500℃. Although activation energy of coated steel corrosion was lower than the uncoated one, the coating provided preferable high-temperature corrosion resistance. After exposure to SO₂, the appearance, element contents and phase structure of the sheets were characterized. Potassium sulfate (K₂SO₄) crystal grains were found to form on the coating surface. However, K₂SO₄ was not detected inside coating because relatively dense coating blocked sulfur diffusion.