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Corrosion protection on grey cast iron

 

Dear Sir, we are one of the air brake manufacturers in India. Most of our products are made up of Grey cast Iron. Presently we are doing phosphating and oiling/waxing as a corrosion protection coating. But we are not getting enough salt spray hours when we conduct test in Neutral Salt. We need the components to withstand for 150 hours in salt spray test. Also, we have gone for a new proprietary product(liquid) which is Molybdenum Disulfide based called as Triboseal. But we are not getting the result expected. Our component has more crevices and holes. We need an expert solution from you possibly.

Best regards,

D.DHANASEKAR
Sab Wabco India Limited - Hosur, Tamil Nadu, India

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Cathodic electro deposited epoxy coating normally withstands 1000 hours of salt spray test (ASTM B117). However, on shot blasted castings the results will be lower but in any case far better than the 150 hours required by you. CED coating or Electrocoat or Cataphoretic coating is widely used in automotive components.

Gurvin Singh
Mohali, Punjab, India
 

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Dear,
We are using CED coating on one of our cast iron parts (approx. 12 Kg) and we have to apply spray paint over it to achieve 150 hrs salt spray resistance.
What could be reasons or may be if someone could suggest a checklist to find a solution to avoid additional spray coating.
Thanks

Richard Milosky
giavino automot - Toronto, Canada
2007