Zinc Plate and Passivation Spec 1

[mprice]

Does anyone know which standards (Euro Norms or equiv)do I need to use when specifying: A) Electrolytic Zinc Plating of formed mild Steel sheet metal parts and B) Passivation using Cr3 and conforming to RoHS. This will be used in an office machine. Thanks Matt

 

[Goahead]

Hi,
the following is possibly what you are looking for:

BS EN 10152

ELECTROLYTICALLY ZINC COATED COLD ROLLED STEEL FLAT PRODUCTS FOR COLD FORMING - TECHNICAL DELIVERY CONDITIONS

Regards,

http://www.welding-advisers.com/

 

[arto]

how about ASTM B-633 for Galv. & ASTM A-967 for passivation?

 

[mprice]

Thanks to Goahead and arto for your responses.
I actually need the EuroNorm standards (if they exist) for two processes, they are:
1) Electrolytic Zinc Plating process of low carbon steel sheet metal parts. I think I need the EN equivalent of ASTM B633. For example a simple bracket is formed from DC01(EN 10139) and then is sent to the platers for a coating of zinc by electrolytic deposition.

2) Chromate Passivation is the process of passivating the Zinc coating, which improves its corrosion resistance. This is something the plater does after applying the Zinc coating.

The problem with some Chromate Passivation processes is that they use Hexavalent Chromium which is becoming a banned substance in Europe because of RoHS (Reduction of Hazardous Substances) for elctronic goods. So I need to specify a process that uses Trivalent Chromium as this is not banned by RoHS.

The standard BS EN 10152 is for eletrogalvanising steel during the rolling process with a thin layer of pure zinc.
A trade name for this type of material is Zincor(r).

I have also found a EuroNorm EN 10327 which is not what I am looking for but covers the hot dipped Zinc/Al coating of steel strip. A trade name for this is AluZinc eg AZ150.

So if anyone has any more precise info please let me know.
Thanks again
Matt

 

[TVP]

Matt,

The EN standard for electrodeposited zinc coatings is EN 12329 Corrosion protection of metals - Electrodeposited coatings of zinc with supplementary treatment on iron or steel. Chromate coatings are covered by EN ISO 3613 Chromate conversion coating on zinc, cadmium-aluminium-zinc alloys and zinc-aluminium alloys - Test methods. The chromate spec does not specifically require trivalent coatings. A typical drawing specification would be "Electrodeposited zinc plus trivalent chromate to meet BS EN 12329 & BS EN ISO 3613.