Can we use Cold Rolled Sheet Metal for Hot Dip Galvanizing (batch type)
April 23, 2020
Q. Dear Sir,
I am Gopinath working as a Quality Head in Cable tray manufacturing company.
We are doing hot dip galvanizing (7 Tank Process as per IS 2629) on cable trays. The base metal of cable tray is hot rolled sheet (as per IS 1079 or ASTM A621 or EN 10111).
7 tank galvanizing process steps are:
1. Degreasing cleaning (Caustic soda).
2. Water rinsing.
3. Pickling process (HCl Soln.)
5. Fluxing process (Ammonium chloride).
6. Galvanizing (Using 99.995 pure zinc).
7. Water Quenching & Post treatment.
Now our customer demands we do cable trays with base metal should be cold rolled sheet (as per IS 513 or ASTM A1008 or EN 10130).
We have discussed with some experts in our local area galvanizers, regarding possible galvanizing on cold rolled sheets, but they told us if hot dip galvanizing done on cold rolled sheet some problems chance to happen after galvanizing. i,e.,br 1. Zinc peeling off, 2. Non uniform coating, Roughness, etc.
So we have in big trouble to resolve this issues.
I am requesting you please suggest how to do galvanizing on cold rolled sheet metal.
Is it required any process to add or remove (as said above 7 tank process) to do galvanizing on cold rolled sheet metal to achieve proper galvanizing?
Please suggest what is the best to do galvanizing on the cold rolled sheet.
Thanks and regards,
Profab Engineers Pvt Ltd - mumbai, India