不锈钢表面TiN、TiO2涂层化学气相沉积制备及抑焦性能研究

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

摘要:

为抑制不锈钢材料表面催化结焦，采用常压化学气相沉积法，实现了在10?0?.9 mm的310S型不锈钢试样表面TiN和TiO2涂层的直接沉积，沉积温度均为850 ℃，沉积时间为2.5 h。通过SEM、EDS和XRD分析了涂层的形貌特征和组织结构，结果显示，TiN和TiO2涂层表面均匀完整，粒子结合紧密；氮化钛为立方晶相结构，Ti和N原子比约为1:1，氧化钛是非计量化合物，它的组成为Ti2O3~Ti3O5。分别以正己烷、环己烷、苯和RP-3为原料，采用自制的常压裂解装置对TiN和TiO2涂层的抑制结焦效果进行了评价。结果表明，TiN涂层对正己烷、环己烷、苯和RP-3的结焦抑制率分别为99.91%、86.19%、72.36%和94.68%，而相对应的TiO2涂层则为83.39%、85.77%、57.78%和68.57%，TiN涂层具有更优良的抑制结焦性能；310S空白片表面以丝状焦为主，TiN和TiO2涂层表面以吸附气相结焦为主。

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.