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A Comparative Study of the 0.05Al Process. October 2, 2012. Background. Al for broadband Si reactivity control H. Guttman and P. Niessen, 1975 M. Pierre, 1975 Commercialization failure of Polygalva, 1979 Al-compatible flux (G-flux) US Patent US 7,811,389 B2, 2010
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A Comparative Study of the 0.05Al Process October 2, 2012
Background • Al for broadband Si reactivity control • H. Guttman and P. Niessen, 1975 • M. Pierre, 1975 • Commercialization failure of Polygalva, 1979 • Al-compatible flux (G-flux) • US Patent US 7,811,389 B2, 2010 • Commercial production of 12Al coating
Parts • Steel Parts (2982 kg in total) • 0.04% - 0.28% Effective Si
Baths, Centrifuge and Products • Baths (2400 kg each) • Bath A: 0.039%Al • Bath B: 0.051%Al • Bath H: 0.005%Al
Pretreatments Degrease 20 minutes Pickle 20 minutes Rinse 1 minute Dry 120ºC 15 minutes Flux 1 minute
Coating Thickness (4 minutes) 450ºC (842ºF), 4 minutes
Coating Thickness (Prior Study) 440ºC (824ºF), 8 minutes
Coating Thickness (10 minutes) 450ºC (842ºF), 10 minutes
Coating Adhesion (Part e3) Bath H, 4 min Bath B, 4 min Bath B, 10 min Bath A, 4 min
Microstructure (Part e3, 0.21%Si) Bath H, 4 min Bath B, 4 min Bath A, 4 min Bath B, 10 min
Flaked-off Coating Bath H, 4 min Bath H, 4 min ζ Bath A, 4 min Bath B, 10 min δ
Coating Adhesion (Part a) Bath H, 4 min Bath A, 4 min Bath B, 10 min
Microstructure (Part a, 0.24%Si) Bath H, 4 min Bath A, 4 min Bath B, 10 min
Drainage (Part k) The amount of accumulation at the bottom of Part k: Student’s test indicated that there were significant differences between Baths H and AB, whereas there was no significant difference between Baths A and B.
White Rust Test H08 B132
Summary • New Process (0.04-0.05%Al) vs. HDG • Al-compatible flux (G-Flux) • Brighter, shinier and thinner coating • Improved coating adhesion • Slightly better drainage • Slightly more dross but same amount of ash • Less visible oxide skin • More localized white rust • Slightly shorter kettle life
Questions? • Thank you for your attention!