Oxidation Studies of T-91 and T-22 Boiler Steels in Air at 900°C

Dinesh Gond, Vikas Chawla, D. Puri, S. Prakash

Heavy Electrical Equipment Plant, Bharat Heavy Electricals Limited, Haridwar-249403,India.
Mechanical Engineering Department, L.L.R.I.E.T., Moga, Punjab-152002, India.
Metallurgical & Materials Engineering Department, Indian Institute of Technology Roorkee,Roorkee 247667, India.

DOI: 10.4236/jmmce.2010.98053                

Abstract

The oxidation behaviour of T-91 steel and T-22 steel in air has been studied under isothermal conditions at a temperature of 900°C in a cyclic manner. Oxidation kinetics was established for the T-91 steel and T-22 steel in air at 900°C under cyclic conditions for 50 cycles by thermogravimetric technique. Each cycle consisted of 1 hour heating at 900°C followed by 20 min of cooling in air. T-91 steel sample followed somewhat linear rate of oxidation while T-22 sample followed the parabolic rate law of oxidation. X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray (SEM/EDAX) techniques were used to characterise the oxide scales. T-91 steel was found to be more corrosion resistance than T- 22 steel in air oxidation for 50 cycles.

Keywords

Hot corrosion; T-91; T-22

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	J.C. Van Wortel, C.F. Etienne, F. Arav, Application of modified 9chromium steels in power generation components, in: VDEh ECSC Information Day, The Manufacture and Properties of Steel 91 for the Power Plant and Process Industries, Dusseldorf, 5th November, 1992, paper 4.2.
[2]	T. Fujita, Current progress in advanced high Cr steel for high temperature applications ISIJ Int. 32 (2) (1992) p.175.
[3]	J. Orr, A. Di Gianfrancesco, The effect of compositional variations on the properties of steel 91, in:VDEh ECSC Information Day, The Manufacture and Properties of Steel 91 for the Power Plant and Process Industries, Dusseldorf, 5th November, 1992, paper 2.4.
[4]	ASTM, Standard specification for seamless ferritic and austenitic alloy-steel boiler, superheater and heat-exchanger tubes, A 213/A 213M-90a, 1990.
[5]	ASTM, Standard specification for seamless ferritic alloy-steel pipe for hightemperature service, A 335/A 335M-95a, 1996.
[6]	R. Panton-Kent, Phase balance in 9%Cr1%Mo steel welds. TWI report, Bulletin 1, January/February 1991, p.15.
[7]	G.E. Birchenall, A brief history of the study of oxidation of metals and alloys, in: High Temperature Corrosion, Proceedings, NACE, San Diego, CA, 1981, p.3.
[8]	D.A. Jones, Principles and Prevention of Corrosion, second ed., Prentice Hall, USA, 1996.
[9]	P. Kofstad, High-temperature Corrosion, Elsevier Applied Science, London, 1988, pp. 382–385 (Chapter 11).
[10]	I. Saeki, T. Saito, R. Furuichi, M. Itoh, Growth process of protective oxides formed on type 304 and 430 stainless steels at 1273°K, Corros. Sci. 40 (8) (1998) p.1295.
[11]	S. Jianian, Z. Longjiang, L. Tiefan, High temperature oxidation of Fe–Cr alloys in wet oxygen, Oxid. Met. 48 (3, 4) (1997) p.347.
[12]	Z. Tokei, H. Viefhaus, H.J. Grabke, Initial stages of oxidation of a 9CrMoV steel: role of segregation and martensite laths, Appl. Surf. Sci. 165 (1) (2000) p. 23.
[13]	A.P. Greeff, C.W. Louw, H.C. Swart, The oxidation of industrial FeCrMo steel, Corros. Sci. 42 (10) (2000) p.1725.
[14]	A. Arztegui, T. Gomez-Acebo, F. Castro, Steam oxidation of ferritic steels: kinetics and microstructure, Bol. Soc. Esp. Ceram. Vidr. 39 (3) (2000). p. 305.
[15]	A.S. Khanna, P. Rodriguez, J.B. Gananamoorthy, Oxidation kinetics, breakaway oxidation, and inversion phenomenon in 9Cr–1Mo steels, Oxid. Met. 26 (3, 4) (1986) p.171.
[16]	Dionisio Laverde, Tomas Gomez-Acebo ,Francisco Castro, Continuous and cyclic oxidation of T-91 ferritic steel under steam, Corrosion Science 46 ,2 July 2003, pp.613–631.
[17]	X. Wu, D. Weng, Z. Chen, L. Xu, Surface Coating Technology, 140 (2001), p.231.
[18]	P. Niranatlumpong, C.B. Ponton, H.E. Evans, Oxid. Met, 53 (3–4) (2000), pp. 241-258.
[19]	Buta Singh Sidhu, S. Prakash , Performance of NiCrAlY, Ni–Cr, Stellite-6 and Ni3Al coatings in Na2SO4–60% V2O5 environment at 900°C under cyclic conditions, Surface & Coatings Technology 201,17 April 2006, pp.1643–1654.
[20]	S. Danyluk, J.Y. Park, Corrosion 35 (12) (1979) p.575.
[21]	D. Wang, Surf. Coat. Technol. 36 (1988) p.49.
[22]	S.E. Sadique, A.H. Mollah, M.S. Islam, M.M. Ali, M.H.H. Megat, S.Basri, Oxid. Met. 54 (5–6) (2000) p.385.
[23]	N.S. Bornstein, M.A. Decrescente, H.A. Roth, Proc. of Conf. on Gas Turbine Mater in the Marine Environment, MMIC-75-27, Columbus,Ohio, USA, 1975, p. 115.
[24]	U.K. Chatterjee, S.K. Bose, S.K. Roy, Environmental Degradation of Metals, Marcel Dekker, New York, 2001.
[25]	A.K. Misra, J. Electrochem. Soc. 133 (5) (1986) p.1029.