Comparative Study on Atmospheric Corrosivity of Under Shelter Exposure in Yangon and Mandalay (Myanmar)

  • Yu Yu Kyi Win Ph.D Candidate, Department of Civil Engineering, Yangon Technological University, Yangon, Myanmar
  • Thinzar Khaing Ph.D., Associate Professor, Department of Civil Engineering, Yangon Technological University, Yangon, Myanmar
  • Zaw Min Htun Ph.D., Associate Professor, Department of Civil Engineering, Yangon Technological University, Yangon, Myanmar
  • Yasuo Suzuki Dr.Eng., Assistant Professor, Department of Civil and Earth Resources Engineering, Kyoto University, Kyoto 615-8540
  • Kunitaro Hashimoto Dr.Eng., Associate Professor, Department of Civil Engineering,Kobe University, Kobe 657-8501
  • Kunitomo Sugiura Ph.D., Professor, Department of Civil and Earth Resources Engineering, Kyoto University, Kyoto 615-8540
Keywords: Carbon steel and weathering steel, under shelter corrosion, ISO 9223 corrosivity classification.

Abstract

Corrosion is a degrading process and it is the main degradation problem in building industry around the world. This study emphasises on the corrosivity classification of studied areas and discusses long term prediction for thickness loss of carbon steel and weathering steel under shelter condition. Two locations, Yangon and Mandalay, are selected as study areas in Myanmar. Corrosion rates are measured after one year exposure. The pollutant data of sulphur dioxide and chloride deposition rates are measured according to JIS Z 2382 and the meteorological data are collected by Easy USB data logger. The corrosion rate is classified based on ISO 9223 by evaluating the important atmospheric variables, such as time of wetness, CL- and SO2. The classes of sulphur dioxide and chloride deposition rate can be seen low level for both areas and Time of Wetness (TOW) can be seen τ4 for Yangon and τ3 for Mandalay.So, according to ISO 9223, the corrosivity category for Yangon area is C3 and that for Mandalay area is C2-C3. The actual mass loss for weathering steel is a little more than that of carbon steel in Yangon and adverse condition can be seen in Mandalay after one year period. Then the future corrosion rates of studied areas are discussed based on long time test results from JFE Steel Corporation, Japan. From this, weathering steel is suitable when chloride deposition rate is less than or equal to 0.05 mdd because of its protective properties.

References

[1] Roberge PR, Handbook of Corrosion Engineering. The McGraw-Hill Companies, Inc; New York 2000.
[2] Hays, G.F.(2010)Now is the Time. World Corrosion Organization.
[3] N. B. S. Publication, Economic Effects of Metallic Corrosion in the United States, Publication No. 511, National Bureau of Standard, Washington, DC (1987).
[4] Katsuhiko Asami and Michio Kikuchi, “Characteristics of Rust layers in weathering steels: Air-exposed for a long period” Institute of Material Research, Tohoku University, Sendai 980-8577, Japan
[5] corrosion-doctors.org/AtmCorros/iso9223.htm
[6] ISO 9223: Corrosion of metals and alloys—corrosivity of atmospheres— classification.
[7] http://en.m.wikipedia.org/wiki/Yangaon
[8] http://en.m.wikipedia.org/wiki/Mandalay
[9] Japan Industrial Standard, JIS Z 2382, Determination of pollution for evaluation of corrosivity of atmosphere.
[10] ISO 9226: Corrosion of metals and alloys—corrosivity of atmospheres— determination of corrosion rate of standard specimens for the evaluation of corrosivity.
Published
2017-01-26
Section
Articles