ANALYSIS OF DENICKELIFICATION PHENOMENON ON HEAT EXCHANGER TUBE
DeNickelification is common phenomenon which occurs for alloy metal containing sufficient amounts of Nickel when it is exposed at high temperature in long time periode. One of component which is made of alloy metal containing Nickel is heat exchangers tube. Â Heat exchanger is a part of processing unit that use for transfering heat from hot fluid to colder fluid through the combined mechanisms of conduction and convection. Â When the heat exchanger leaks, all of the processing system could be affected.Â In this research a leakage heat exchanger tube is investigated by failure analysis methods to find the root cause of failure.Â Several tests and examinations such as fractography, metallography examinations, SEM and EDS, hardnes as well as chemical compositions test are carried out to this tube to obtain detailed information for further analysis.
Result of this reseach shows that some Cu residue, Ni, aggressive/corrosive ion such as Cl- and S2- at the leak area of heat exchanger tube is found.Â These evidences indicated that denickelification was occurred on inner surface of heat exchanger tube caused by potential difference between Ni2+ion and Cu2+ ion to form a galvanic cell. Â Furthermore, since the tube is flown by fluid material which contains aggressive / corrosive ions such as Cl- ion and S2- then pitting corrosion on inner surface of tube is formed. This mechanism had been taken place continuously during operation of heat exchanger and pitting corrosion keep growing until the tube leaks.
Kakac, Sadik & Hongtan Liu, â€œHeat Exchanger Selection, Rating, and Thermal Designâ€, 2nd edition, CRC Press, Florida, 2002
Savory, Eric, â€œLecture 8 - Basic of Heat Exchangerâ€, Department of Mechanical and Material Engineering, University of Western Ontario, 2000
â€œStandard of Tubular Exchanger Manufactures Associationâ€, 8th edition, Tarry Town, New York, 1999
Ezuber, Hosni M., dkk, â€œCorrosion Behaviour of Copper-Nickel Alloys in Seawater Environmentâ€, NACE Paper No. MECCFEB16-9103, 16th Middle East Corrosion Conference and Exhibition
Massalski, T.B & H.Okamoto, â€œBinary Alloys Phase Digramâ€, 2nd edition, American Society for Metals, Metal Park, Ohio, 1980
ASM Handbook Committe, â€œMetallography and Microstructuresâ€, Vol 9, Ninth Edition, Metal Handbook of ASM, American Society for Metals, Ohio, 2002
ASTM E112, â€œStandard Test Methods for Determining Average Grain Size,â€American Standard Testing of Material, 2013
ASTM B466, â€œStandard Specification for Seamless Copper-Nickel Pipe and Tubeâ€, American Standard Testing Material, 2014
Liu, Jun-Fu, dkk, â€œDeNickelification and Dezinfication of Copper Alloys in Water Environmentsâ€, Microsc. Microanal., Microscope Society of America, Vol.139, Isuue 3, 2015
French, David N., â€œMetallurgical Failures in Fossil Fired Boilersâ€, John Wiley & Sons Inc, p.197-203, 1993
Fontana, Mars G., â€œCorrosion Engineeringâ€, 3rd. Edition, McGraw Hill Book Company, 2005
Jones, Deny A., â€œPrinciple and Prevention of Corrosionâ€, ....
Thulukkanam, Kuppan, â€œHeat Exchanger Design Handbookâ€, 2nd edition, CRC Press, 2000
Lenard, D. & R.R. Welland, â€œCorrosion Problem with Copper-Nickel Components in Sea Water Systemsâ€, Defence Research Establishment Atlantic
Cincera, Silvia, dkk, â€œDe-Nickelification of 70/30 CuproNickel Tubing in a Cooling Heat Exchangerâ€, Journal of Failure Analysis and Prevention, Vol.12, Issue 3 hal.300-304, 2012
http://www.corrosionlab.com/papers/technical-brief-deNickelification.htm accessed in February 2018
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