| In this paper, SiO2-based ceramic coatings were prepared on 1Cr18Ni9 steel by slurry method, and SiO2-based nanostructured composite ceramic coatings were prepared on Q235 and 1Cr18Ni9 by thermo chemical reaction method. Experiments of using aluminum hydmic phosphate as adhesive and selecting NaAlSi3O8,SiO2,MgO,Al2O3 as ceramic particles. The optimal ratio of aluminum hydmic phosphate and ceramic particle of slurry was determined by multiple tests. The microstructures and interface bonding of the coatings were analyzed by means of SEM and X-ray diffraction. The results show that the ceramic coatings solidified at 400℃,600℃and 800℃are found to contain new phases, and the bonding of coating and basal body solidified at 600℃are better than 400℃. And then thermal shock resistance,bond strength,corrosion resisting and wear-resisting test were done, the results show that the performances are improved greatly by the ceramic coating, the performances of nanostructured coating are better than micron coating, and the performances of 40% nanostructured coating are the best. The resistance to salt, acidresistivity, resistance to alkali, adhesion-wear relative abradability, grain-abrasion relative abradability based on Q235 have respectively raised 40 times, 14 times, 3 times, 6 times and 4 times; The resistance to salt, acidresistivity, resistance to alkali, adhesion-wear relative abradability, grain-abrasion relative abradability based on 1Cr18Ni9 have respectively raised 21 times, 3.6 times, 0.7 times, 5.2 times and 4.7 times. The thermal shock resistance of 40% nanostructured coating has reached more than 30 times.
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