Can steel be anodized? If so, how?

A. Hi Josh; hi Manalel. Aluminum oxide can form a tight, tenacious, corrosion resistant coating on aluminum, such that aluminum can be beneficially anodized. But iron oxide (rust) will not to my knowledge form a tight, tenacious, corrosion resistant coating on steel, so I don't think it can be beneficially anodized.

I don't know what you have in mind by 'similar results'. Nitriding would give a wear resistant surface, but it is conductive (unlike anodizing which is an insulator); further, it cannot absorb dye. Paint, powder coating, or electrophoretic lacquering might do what you want but would not be as hard or wear-resistant as anodizing. Certain platings might achieve what you could be looking for. If you can detail what characteristics you are looking for, people can possibly direct you to finishing processes that might deliver them.

A. Anodizing forms an oxide protective barrier on aluminum but if you form iron oxide over steel it will not protect it adequately, for that reason a different compound has to be developed. You may want to explore blackening, galvanizing or phosphate coating of steel.

A. Hi. Some companies claim that they know an Electrochemical Process for stainless steel wherein Chrome Oxide can be produced/enhanced and by varying the thickness it attains different color. Maybe you are talking about that? But, to the best of my knowledge, the term "Anodizing" is used only for Anodizing of Aluminum.

Thanks,

A. You do not want to want to make the surface of steel more anodic. To protect it, it should have a continuous cationic coating.

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? Hi Fred. I don't understand that one at all. Are you suggesting cataphoretic electrocoating (CED)? Please expound. Thanks.

Regards,

Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey

December 16, 2008
A. Hi. Anodizing is used only for Aluminum, but for steel you can use metal spray (with Aluminum wire) over it.
After that you can Anodize it.
Good luck

A. Hi Basheer. There is no such commercial process. But you might wish to review the previously suggested pdfs for experimentation purposes.

Regards,

A. Hi Muhammed. It is indeed very easy to get confused when you ask whether steel can be anodized because it depends on exactly what you mean by "anodized" :-)

Trying to guess what your competitor is doing from the color of the coating may not get you too far. Might it be a QPP salt-bath nitriding process? Or a solid-film lubricant process? What properties does it offer that the customers are finding attractive?

Regards,

A. "Our competitors' kingpins (knuckle pins) are far better wear & corrosion resistant. I mean, better than hard chrome plated or carburized (case hardened & ground)."

In that case I would think that their product is carbonitrided, or nitrocarburized, both of which mean almost the same thing. And ... it's fairly deep, maybe .010" to .025"

That's the only way I know of to beat carburized and hardened and hard chrome.

A. Hi Muhammed. I don't know about "optimum", but yes, the point is that Q-P-Q should be an appropriate process for your needs!

Regards,

A. Hi. I do not believe there is any mechanical finishing process or conversion coating process which can make a steel pot into appropriate bakeware or cookware ... but as you mention, there are various coating processes that will do so.

Regards,

A. Hi Shahin. The previously offered pdfs from New Mexico Tech seem to explain all of the solutions they tested as well as their exact preferred embodiment. I do not understand what you mean about not being able to find a way: please clarify.

What are you expecting from the process; what properties are you looking for; what are you doing; what are you attaining? Let's not run in circles please, but try our best to move forward based on what has already been said :-)

Regards,

A. Hi Randy. I don't know what finish is on your cast iron parts, but it's certainly not anodizing. If they are not plated with anything, just bare cast iron, phosphatization would be the normal pretreatment. You can't do true phosphatization yourself, but you can apply Naval Jelly [linked by editor to product info at Amazon] which is the consumer's best imitation of a phosphatized coating. If the parts are plated with something like zinc, nickel, or chrome, you could try an adhesion promoter =>
But if that doesn't work well enough (and it probably won't work great), you would probably have to remove the plating before painting, or have the parts replated instead of repainted. Good luck.

Regards,