摘要
Abstract
The element distribution,composition,surface morphology,and thickness of the oxide film on inner surface of the pyrolysis furnace radiant coil on service were investigated.The oxide film anti-coking and anti-carburization performances were evaluated.The results showed that normal coil 1#,2# oxide film mainly contained Cr2O3,in which Cr content reached over 50％(w),Mn content was about 10％(w),and the sum of Fe and Ni contents were about 15％(w).Serious coking coil 3#,4# oxide film mainly contained magnetite(iron oxide),in which Cr content was about 15％(w),Mn content was less than 2％(w),and the sum of Fe and Ni contents reached 60％(w).The thickness of 1#,2# oxide film was about 20 μm and the oxide films were compact.The thickness of 3#,4# oxide film was about 40 μm and the oxide films were loosen.After coking test,1#,2# oxide film was covered with filamentous coke,and the 3#,4# oxide film was covered with cotton-shaped coke.The anti-coking performance rank was 1#＞ 2#＞ 4#＞ 3#.After carburization test,the 4 oxide films converted into Cr3C7 and graphite partly,and the anti-carburization performance rank was 1# ＞ 2# ＞4# ＞ 3#.关键词
裂解炉管/氧化膜/结焦/碳化Key words
pyrolysis furnace radiant coil/oxide film/coking/carburization分类
化学化工
