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Can't get consistent Brightness in galvanizing

1999

We have a line for hot dip galvanizing of steel wire, and I have two questions about it:

1-When we galvanize low carbon steel wire with 50-60 gr Zinc /m2. can't get a uniform bright surface, we get alternating bright and matte finish zones. Maybe it could be the alloy layers that appears in the surface? Somebody had this problem and know the solution?

2-We are thinking to install an electroplating line for steel wire also. (because the surface appearance is so important for us.) What process will be the more adequate? Cyanide or non cyanide bath?

Thanks a lot in advance.

VICTOR MENDOZA PEREZ
- CALLAO - PERU

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2000

Dear Mr. Mendoza Perez,

you should have a look to the cooling after wiping of the wire. Only a proper cooling will give you a bright surface.

As you get bright surfaces in some areas it does not look like a problem with pretreatment or wiping.

Best regards,

Peter Kordt
- Hagen, Germany

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Brightness increases on the finer particle size of the Zinc and by faster cooling you reduce the particle size. This may also be dependent on Steel Chemistry (Silicon ?) or Flux concentration/time. Can you comment on these?

Regards,

Sudhir Joshi
- Mumbai, Maharashtra, India
2002