Metal finishing Q&As since 1989

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Degreasing of 300 and 400 series stainless steel

 

I am working in a organization dealing with cold drawing of stainless steel (300 & 400 series). After drawing of the coils, the lubricant powder is stuck to the drawn coil. We use a proportion of potassium permanganate [on eBay or Amazon] & SODIUM HYDROXIDE solution for degreasing of the coils, but the lubricant powder doesn't get removed completely. My enquiry is is there any other compound or solution which can be used for degreasing of the coils.

Thanks,

Vijayan R Nair
- Mumbai, Maharashtra, India

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Vijayan:

What is the chemical makeup of the lubricant powder? Have you tried using some surfactant in the NaOH solution to help? Is it possible to use ultrasonics? Depending on what the material is, you may not be able to take it off chemically without some mechanical action.

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois

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October 5, 2008

what is the best solution(economic,safer, efficient ) for degreasing stainless steel line?
and is it efficient to use citric acid for pickling and passivation instead of nitric acid solution (it is more dangerous to use)

thanks for your hospitality

Respectfully yours

Hamid Omranian
- IRAN

Hi, Hamid. Degreasing, pickling, and passivation are three different requirements and three different processes. You cannot use one chemical to do all three jobs.

In general, you do pickling first, before mechanical operations, and pickling of stainless steel will usually involve nitric and hydrofluoric acid. Cleaning/degreasing usually involves hot alkaline processes. Passivation is usually the final process and may involve either nitric acid or citric acid .

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 12, 2008