passivation????

[rayenginee]

Does anyone know how to passivate stainless steel?? I'd like to setup a tank to passivate small stainless steel parts.
Any help would be greatly appreciated.

[ty1295]

I am not sure HOW, but know we send parts out at work to get done.

I will ask how for you though.

[metlmunchr]

Passivating uses an acid (nitric maybe, but not sure) to eat away the active iron at the surface, essentially leaving a higher concentration of chrome and nickel at the surface. I imagine you can find a lot of information on it at http://www.finishing.com They cover about every treatment that can be done to the surface of a material.

[whiteriver]

Do you want Passivation or Electropolishing? 300 or 400 series stainless? I set up my home shop 7 years ago to do both. If you just want passivation then all you need is a respirator rated for acid fumes. Rubber gloves and apron. Face shield and safety glasses. Use Nitric acid and water to the right concentration. You also need caustic soda to neutralize the rinse water and a ph meter to monitor the rinse water. Be damn carefull with the fumes. Nitric is cheap I bought 15 gallons a little while back for $75. That will last many years. The wanted $400 for the container so I just bought a $15 used stainless beer keg and put it in that. Same thing they ship it in.
Now electropolishing I say farm it out. They quoted me over 50 grand for my set up. I built it myself for around 10 grand. But then I use it every week.

Donny

[BobUXL]

Passivation is not that complicated, but it does involve using acids at elevated temperatures in particular time intervals. If you search the web, you can get information on the setup. But you also need to be very cautious because there are many hazards involved and you will need to use proper ventilation and treatment of the vapors.

Bob

[SRT]

I suggest that for your own protection, and the protection of your users and the environment, you should be aware: that if a drawing plating, etc., specification is shown, that there may be, or are, different types of requirements that must be met, or you may be held responsible if they were not properly complied with. I suggest that you check it out before proceeding on what you are adding to your product, and how you are to dispose of the waste created. I know of a local company official that was put in prision for several years, for not following the requirements correctly.

[lapuser]

According to the AWS , passivation involves a solution of nitric and hydrofluoric acids with distilled water. Nitric acid has an ugly msds that won't quit and concentrated hydrofluoric acid if it ever gets on you will not stop eating your flesh away until you get it cut out at the emergency room. I once looked into this for some work and determined that due to all the SERIOUS health risks I was not interested. There is also a newer passivation process out there that involves some sort of derivative from oranges and I remember reading of it but did not pursue it so all I can suggest is do a web search. The other guy is right about waste disposal because if you do this in any quantity you will have to at least have a plan ready to go if the enviro wackos start to ask you questions. I do not believe that in general you can make enough money off this to be worth the headache. It's kind of like heat treating and chrome plating in that you hire the guy who does it for a living and spare yourself lots of grief. If you really insist that you want to do this I would start at the American Welding Societies web site and go from there. Good luck

[lapuser]

http://www.pfonline.com/articles/059905.html Found this after looking at the first page of results for passivation on google.