两种气氛预氧化后裂解炉管合金的结焦和碳化行为  

Coking and Carburization Behaviors of Radiant Coils in Pyrolyzer Alloy Pre-Oxidized in Two Atmospheres

作　　者：王申祥[1,2] 王国清[2] 王红霞[2] 郏景省[2] 崔立山[1] 

机构地区：[1]中国石油大学(北京)理学院,北京102249 [2]中国石化北京化工研究院,北京100013

出　　处：《石油化工》2014年第9期1000-1007,共8页Petrochemical Technology

摘　　要：研究了裂解炉管用HP40合金在H_2-H_2O及空气-H_2O气氛中预氧化后的表面形貌、元素分布及相组成,并在98%(φ)N_2-2%(φ)C_2H_6和98%(φ)H_2-2%(φ)CH_4气氛中研究了预氧化合金的结焦和碳化行为。实验结果表明,HP40合金在H_2-H_2O中形成的氧化膜由致密的笼型球团状MnCr_2O_4尖晶石组成;而在空气-H_2O中形成的氧化膜发生剥落,且Fe和Ni元素在剥落处富集,未剥落的氧化膜由八面体MnCr_2O_4尖晶石及Cr_(1.3)Fe_(0.7)O_3氧化物组成。经H_2-H_2O预氧化的合金结焦后表面存在少量不连续的絮状焦炭,而经空气-H_2O预氧化的合金结焦后表面覆盖了大量丝状焦炭,前者的结焦量占后者的17%。经H_2-H_2O预氧化的合金的氧化膜碳化后仍为致密的MnCr_2O_4尖晶石;而经空气-H_2O预氧化的合金的氧化膜转化成由(Cr,Fe)_7C_3和Fe_3C组成的碳化物膜。HP40 alloy was usually used in radiant coils in pyrolyzers.The surface morphology,phase structure and element distribution of the HP40 alloy samples pre-oxidized in H2-H2O and air-H2O atmospheres were investigated.The coking and carburization behaviors of the pre-oxidized samples were studied in 98％（φ）N2-2％（φ）C2H6 and 98％（φ）H2-2％（φ）CH4 atmospheres.The results showed that the oxide film grown in H2-H2O was composed of cage-shaped pelletizing MnCr2O4 spinel,while the exfoliation of the oxide film grown in air-H20 occurred and the elements Fe,Ni were enriched there,and the un-exfoliated oxide film was composed of octahedral-shaped MnCr2O4 spinel and Cr1.3Fe0.7O3 oxide clusters.The sample pre-oxided in H2-H2O was covered with a small amount of discontinuous floc coking,while the sample pre-oxided in air-H2O was covered with a lot of filamentous coking.The coking mass of the former was about 17％ of that of the latter.The oxide film grown in H2-H2O remained unchanged after carburization test,but the oxide film grown in air-H2O was converted into the carbide film consisting of （Cr,Fe）7C3 and Fe3C.

关 键 词：裂解炉管 乙烯 HP40合金 预氧化 结焦 碳化 

分 类 号：TQ221.21[化学工程—有机化工]