G. Bi, Y. M. Li, Y. G. Zhang, Shanghai Baosteel Equipment Maintenance Co., Ltd, Shanghai, PRC, Shanghai, China
The CrB2/CoCrAlY coating on the continuing anneal hearth rolls has combined performance with good build-up and wear resistance etc. But it was found by computing with theory of energetics that oxygen can make effect on the existence of the coating: Not only the Cr and Al alloy in the substrate are easy to change into oxide, but also the ceramic phase of CrB2 has the possibility to transform into Cr2O3. It obviously that the oxide will react with the MnO which existed on the surface of steel plate and will result in brittle Mn-oxide, which will be reduced the protection effect and result in build-up and consequently will make the coating failure. Therefore, this paper investigates the behavior of CoCrAlY+ CrB2/Y2O3 coating under oxygen conditions through testing and analyzing the failure coating. Keywords: Coating on hearth rolls, Oxidation, Mn-oxide
Summary: The CrB2/CoCrAlY coating on the continuing anneal hearth rolls has combined performance with good build-up and wear resistance etc. But it was found by computing with theory of energetics that oxygen can make effect on the existence of the coating: Not only the Cr and Al alloy in the substrate are easy to change into oxide, but also the ceramic phase of CrB2 has the possibility to transform into Cr2O3. It obviously that the oxide will react with the MnO which existed on the surface of steel plate and will result in brittle Mn-oxide, which will be reduced the protection effect and result in build-up and consequently will make the coating failure. Therefore, this paper investigates the behavior of CoCrAlY+ CrB2/Y2O3 coating under oxygen conditions through testing and analyzing the failure coating.
Keywords: Coating on hearth rolls, Oxidation, Mn-oxide
