Metal finishing Q&As since 1989

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Iron-Chrome Co-Deposition

I need to plate iron with an iron-chrome alloy (10-15% Cr). Does anyone have an idea if it is possible and how can I do that?

Thanks,

Mario Tagliazucchi
student - Buenos Aires, Argentina
2004

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2004

ASM Handbook volume 5, Surface Engineering, p. 270-273 (1994), covers Cr alloy plating. One Cr-Fe formula: 250 g/L CrO3, 72.2 g/L CrCl3, 62.6 g/L FeCl2, 1 mL/L H2SO4, 20 mL/L CH3OH. The methanol reduces a portion of the Cr+6 to Cr+3. Use at 40 °C (105 F), current density 25 A/dm2 (250 A/ft2), with lead anodes. The reference (US Patent 4,615,773) mentions an optimum pH range 0.5-2.0 and Cr+6:Cr+3 ratio > 2:1, but not the plated composition. Subsequently, low-Cr+6 solutions have been developed which can be varied to produce deposits from 10 to 90% Fe (Plating and Surface Finishing, p. 39, Nov. 1989 and US Patent 5,413,646 -- J. Dash and J. DeHaven, -----).

Modern Electroplating, 4th Edn. (2000) likely has information on newer trivalent Cr solutions (more stable than Cr+6 in presence of Fe+2), but I cannot really say, as my copy is out on loan.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.