4. Electrolytic chromium plating of black iron
Chromium-plated iron differs from tinplate in that the tin layer is replaced by a thin layer of metallic chromium (approx. 0.01 µm or 70 mg chromium on a 1 m 2 face) topped by a layer of partially hydrated chromium (III) oxide (approx. 15 mg chromium on a 1 m 2 face), both formed by electrolysis.
Deposition takes place in a conventional dilute chromium plating bath [50 to 200 g/L chromium trioxide (CrO 3 chromic anhydride)] catalyzed by sulfuric acid (mass ratio H 2 SO 4 /CrO 3 = 1/100) and/or complex fluorides. The higher the density and the lower the bath temperature, the higher the current...
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Electrolytic chromium plating of black iron
Short-term technical outlook
Bibliography
References
Standardization
French Standards Association (AFNOR)
- Fer‐blanc et fer noir simple réduction en feuilles. Qualités, dimensions et tolérances. - NF A 36‐150 - 8‐83
- Fer‐blanc et fer noir simple réduction en bobines destinées à être découpées en feuilles. - NF A 36‐151 - 8‐83
- Fer‐blanc double réduction : feuilles. Qualités, dimensions et tolérances. - NF A 36‐152 - 8‐83
- Fer‐blanc double réduction en bobines destinées...
French manufacturers of electrolytic treatment lines
Clecim.
Dujardin, Montbard, Somenor (DMS)
Organizations
France
Chambre Syndicale des Producteurs de Fer‐Blanc et de Fer Noir, Paris.
Belgium
Centre d'Information de l'Étain, Bruxelles.
Great Britain
International Tin Research Institute, Uxbridge.
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