Dense and well-adherent enamel–nano-Ni composite/enamel–nano-nickel composite coatings were prepared on 304 steel. Their thermal shock (TS) resistance at 400°C as well as the chemical stability in sulfuric acid solution were investigated, and compared with pure enamel coatings. Results indicated that the nanocomposite coatings with 5 wt% of Ni particles exhibited the best resistance to TS. Almost no spalling of the coating occurs after 50 cycles of TS at 400°C. They also provided enough protective effect to the substrates from sulfuric acid corrosion. After 7 days of corrosion, the weight loss of Ni-5 enamel coating was only 1.107 mg/cm2.
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