彭以超,张麦仓,肖将楚,杜晨阳,董建新

• 1:北京科技大学材料科学与工程学院
• 2:中国特种设备检测研究院

摘要(Abstract)：

采用真空渗碳方式对服役2.5年的乙烯裂解炉管钢Cr35Ni45Nb进行了加速渗碳处理,并进行了一系列的高温(1080℃)持久试验;分析了合金在接近实际服役温度下的渗碳特性和持久试验中合金内氧化与蠕变交互作用所引起的材料组织转变、空洞萌生及裂纹形核扩展等规律,重点讨论了渗碳对于合金高温持久寿命的影响机理。结果表明:在高温应力及渗碳因素的叠加条件下,Cr35Ni45Nb炉管近表面碳化物-基体相界面发生内氧化,造成低应力下较易形成空洞和裂纹,而且,裂纹更容易在柱状晶区枝晶间萌生扩展。渗碳时间越久,渗碳层深度越大,Cr35Ni45Nb钢炉管的持久寿命越长。主要原因在于,渗碳造成枝晶间或晶界碳化物增多,降低了合金的蠕变速率,延长了持久寿命;同时,渗碳过程形成的相当于合金内部摩擦力的渗碳应力也部分抵消了外部应力的作用。此外,尽管渗碳强化Cr35Ni45Nb耐热钢,但降低了其高温塑性,同时也会与服役环境下温差热应力及热疲劳损伤等发生交互作用,导致实际服役炉管的早期失效。

关键词(KeyWords)： 真空渗碳;Cr35Ni45;高温持久寿命;内氧化

Abstract:

Keywords:

基金项目(Foundation): 国家高技术研究发展计划(“863”计划)(2012AA03A513)

作者(Author): 彭以超,张麦仓,肖将楚,杜晨阳,董建新

DOI: 10.13289/j.issn.1009-6264.2015.07.029

参考文献(References)：

• [1]Khodamorad S H,Haghshenas Fatmehsari D,Rezaie H,et al.Analysis of ethylene cracking furnace tubes[J].Engineering Failure Analysis,2012,21:1-8.
• [2]Mitchell D,Young D,Kleemann W.Caburisation of heat-resistant steels[J].Materials and Corrosion,1998,49(4):231-236.
• [3]Kaya A,Krauklis P,Young D.Microstructure of HK40 alloy after high temperature service in oxidizing/carburizing environment:I.Oxidation phenomena and propagation of a crack[J].Materials Characterization,2002,49(1):11-21.
• [4]Das A,Roy N,Ray A K.Stress induced creep cavity[J].Materials Science and Engineering A,2014,598:28-33.
• [5]Whittaker M,Wilshire B,Brear J.Creep fracture of the centrifugally-cast superaustenitic steels,HK40 and HP40[J].Materials Science and Engineering A,2013,580:391-396.
• [6]Grabke H,Wolf I.Carburization and oxidation[J].Materials Science and Engineering,1987,87:23-33.
• [7]Wang W,Xuan F,Wang Z,et al.Effect of overheating temperature on the microstructure and creep behavior of HP40Nb alloy[J].Materials&Design,2011,32(7):4010-4016.
• [8]Chen T,Chen X,Lu Y,et al.ASME 2012 pressure vessels and piping conference[C]∥Toronto:American Society of Mechanical Engineers,2012:301-307.
• [9]沈利民.多因素耦合的乙烯裂解炉管损伤分析与寿命预测[D].南京:南京工业大学,2012.
• [10]宫连春.影响HK-40转化炉管使用寿命的原因及措施[J].黑龙江石油化工,2000,11(3):25-27.GONG Lian-chun.Causes of effecting the service life of HK-40 reformer tubes and preventative measures[J].Heilongjiang Petrochemical Technology,2000,11(3):25-27.
• [11]Zhu S,Wang Y,Wang F.Comparison of the creep crack growth resistance of HK40 and HP40 heat-resistant steels[J].Journal of Materials Science Letters,1990,9(5):520-521.
• [12]Jahromi S J,Naghikhani M.Failure analysis of HP40-Nb modified primary reformer tube of ammonia plant[J].Iranian Journal of Science and Technology,2004,28(B2):269-271.
• [13]Alvino A,Lega D,Giacobbe F,et al.Damage characterization in two reformer heater tubes after nearly 10 years of service at different operative and maintenance conditions[J].Engineering Failure Analysis,2010,17(7):1526-1541.
• [14]Swaminathan J,Guguloth K,Gunjan M,et al.Failure analysis and remaining life assessment of service exposed primary reformer heater tubes[J].Engineering Failure Analysis,2008,15(4):311-331.
• [15]Ray A K,Kumar S,Krishna G,et al.Microstructural studies and remnant life assessment of eleven years service exposed reformer tube[J].Materials Science and Engineering A,2011,529:102-112.
• [16]Steurbaut C,Grabke H,Stobbe D,et al.Kinetic studies of coke formation and removal on HP40 in cycled atmospheres at high temperatures[J].Materials and Corrosion,1998,49(5):352-359.
• [17]Zhu Z,Cheng C,Zhao J,et al.High temperature corrosion and microstructure deterioration of KHR35H radiant tubes in continuous annealing furnace[J].Engineering Failure Analysis,2012,21:59-66.
• [18]徐自立,原进秋.国产HP-Nb合金离心铸管的持久性能[J].化工机械,1994,21(2):89-92.XU Zi-li,YUAN Jin-qiu.Creep rupture performance of centrifugal casting pipes made of domestic HP-Nb alloy[J].Chemical Engineering&Machnery,1994,21(2):89-92.
• [19]宋若康.Cr35Ni45钢服役条件下的组织损伤及剩余寿命评估[D].北京:北京科技大学,2014.
• [20]张俊善.材料的高温变形与断裂[M].北京:科学出版社,2007.
• [21]Zhang J,Li P,Jin J.Combined matrix/boundary precipitation strengthening in creep of Fe-15 Cr-25 Ni alloys[J].Acta Metallurgica et Materialia,1991,39(12):3063-3070.
• [22]孙国豪.乙烯裂解炉管性能及失效分析研究[D].大连:大连理工大学,2001.

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