Steel Corrosion Prevention

[atlarson]

I design fixtures, machinery and other production tooling used in our factory. This equipment is often made of steel and protected with paint. However, some items (leadscrews, rollers, gears, part locators, etc) can not be painted. Although the equipment is located inside and is kept dry, these parts tend to develop a thin coating of rust over time. Sometimes we apply oil or grease to prevent this corrosion, but this tends to collect dust and dirt, and is easily transferred to workers clothes or production hardware.

Can anyone discuss the durability / effectiveness / cost / specifications of other coatings or surface treatments for carbon and alloy steel (zinc plating, black oxide, etc).

Thanks,
Andy Larson

 

[rustbuster]

There are thermal spray coatings available, Hasteloy C, etc. Allonizing is another method.

Good luck

 

[rustbuster1]

A good option for protecting surfaces even when they will be subject to gear and other contact loads is to coat them with electroless nickel. Obviously this has a cost and must be reviewed for economic sense, but it is convenient to have done by a plating shop. EN coatings have the unique property of being uniform in thickness rerardless of the shape of the part, which cannot be said for Cr plating or other plated coatings whose thickness depends on cathodic reduction - and therefore the current density at each place on the surface. Zn Cd and other metallic coatings may be suitable for non-wear surfaces and there also are conversion coatings if it's only atmospheric rusting that's to be prevented.

 

[bilge]

Corrosion economics is nicely covered in a chapter of ASM International's Metals Handbook (Ninth Edition) Volume 13: "Corrosion," on pages 369 through 374. The author, Ellis Verink, also has a paper "Economic Appraisals of Corrosion Control Measures" in the Journal of Educational Modules for Materials Science and Engineering, Volume 3, Number 2, 1981.