Properties of oxide films grown on 25Cr20Ni alloy in air-H_2O and H_2-H_2O atmospheres

作     者：Wang Shenxiang Cui Lishan Wang Guoqing Zheng Yanjun Wang Hongxia Jia Jingsheng 

作者机构：College of Science China University of Petroleum Beijing Research Institute of Chemical Industry 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2014年第11卷第1期

页      面：147-154页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：financially supported by the scientific research project of China Petroleum and Chemical Corporation(No.409075) 

主　　题：25Cr20Ni alloy air-H2O H2-H2O oxide film anti-coking resistance to carburization 

摘      要：The oxidation kinetics,surface morphology and phase structure of oxide films grown on 25Cr20Ni alloy in air-H2O and H2-H2O atmospheres at 900 ℃ for 20 h were *** anti-coking performance and resistance to carburization of the two oxide films were compared using 25Cr20Ni alloy tubes with an inner diameter of 10 mm and a length of 850 mm in a bench scale naphtha steam pyrolysis *** oxidation kinetics followed a parabolic law in an air-H2O atmosphere and a logarithm law in a H2-H2O atmosphere in the steady-state *** oxide film grown in the air-H2O atmosphere had cracks where the elements Fe and Ni were enriched and the un-cracked area was covered with octahedral-shaped MnCr2O4 spinels and Cr1.3Fe0.7O3 oxide clusters,while the oxide film grown in the H2-H2O atmosphere was intact and completely covered with dense standing blade MnCr2O4 *** the pyrolysis tests,the anti-coking performance and resistance to carburization of the oxide film grown in the H2-H2O atmosphere were far better than that in the air-H2O *** mass of coke formed in the oxide film grown in the H2-H2O atmosphere was less than 10％ of that in the air-H2O *** Cr1.3Fe0.7O3 oxide clusters converted into Cr23C6 carbides and the cracks were filled with carbon in the oxide film grown in the air-H2O atmosphere after repeated coking and decoking tests,while the dense standing blade MnCr2O4 spinels remained unchanged in the oxide film grown in the H2-H2O *** ethylene,propylene and butadiene yields in the pyrolysis tests were almost the same for the two oxide films.