The Preparation of TiN and TiO2 Coating on Stainless Steel Surface by Chemical Vapor Depostion Method and the investigation o

Abstract:

In order to avoid the catalytic cokes forming, the TiN and TiO2 coating is directly deposited on the surface of the 310S stainless steel flake with the diameter of 10?10?0.9 mm by using atmospheric pressure chemical vapor deposition method. The deposition temperature is 850 ℃ for TiN and TiO2, respectively, and the deposition time is 2.5 h. The morphologies and structures of the coatings were analyzed by SEM, EDS and XRD, the results show that the TiN and TiO2 coating is continuous, close-packed and homogeneous; the titanium nitride in the coating had cub phase, Ti and N atomic ratio in the titanium nitride coating is 1:1, and the titanium oxide in the coating is the Ti2O3~Ti3O5 stoichiometrically. An atmospheric pressure cracking system was set up for evaluating the anti-coking property of TiN and TiO2 coating with n-hexane, cyclohexane, benzene and RP-3 as feedstock. The results show that TiN and TiO2 coating exhibit an excellent anti-coking performance, the anti-coking ratio of TiN coating for n-hexane, cyclohexane, benzene and RP-3 is 99.91%, 86.19%, 72.36% and 99.91%, respectively. Correspondingly, the anti-coking ratio of TiO2 coating is 83.39%, 85.77%, 68.57 and 85.77%, respectively. Hence, the TiN coating has the better anti-coking performance than that of TiO2 coating. The morphologies of the cokes on 310S surface are mainly filamentous cokes, and TiN and TiO2 coatings inhibites the filamentous cokes formation.

Key words:chemical vapor deposition; TiN、TiO2 coating; pyrolysis; coking; anti-coking