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Use of Electrochemical Analysis Method in EG Steel Nubbing Investigation
Technical Paper
2015-01-0732
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
A surface phenomenon associated with the localized excessive growth of phosphate crystals on electrogalvanized (EG) steel is investigated. The excessive phosphate growth (i.e., “nubbing”) is found to correspond to pitting of the EG zinc coating during the degreasing process. In an industry first, alkaline degreasers of varying type are studied using electrochemical analysis and a correlation is found between the EG steel pitting potential and nubbing severity of pre-treated EG steel. Electrochemical analysis of lab-prepared degreaser samples confirms that degreaser pH is primarily responsible for pitting severity. Pretreatment parameter changes are discussed as being able to prevent such a phenomenon.
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Authors
Citation
Dula, M., Eich, H., VanBelle, N., Mohankumar, P. et al., "Use of Electrochemical Analysis Method in EG Steel Nubbing Investigation," SAE Technical Paper 2015-01-0732, 2015, https://doi.org/10.4271/2015-01-0732.Also In
References
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- Hacias , K. Method of Forming Phosphate Coating on Zinc U.S. Patent Re. 35,958 November 17 1998
- Miao , W. , Cole , I. , Neufeld , A. , Furman , S. Pitting Corrosion of Zn and Zn-Al Coated Steels in pH 2 to 12 NaCl Solutions Journal of The Electrochemical Society 154 1 C7 C15 2007
- American Society of Testing & Materials Standard Test Method for Conducting Potentiodynamic Polarization Resistance Measurements ASTM G59-97 2014
- Cramer , S.D. , Covino , B.S. Jr. Metals Handbook ASM International 2003 Frankel , G.S.