-- The Home Page of the Finishing Industry
Serious Education & the most FUN
you can have in metal finishing smiley

No popups, spam, registration or passwords
on this site
current topics
topic 6810



Our 70-meter antenna moves in azimuth on a hydrostatic bearing. We have had corrosion problems on our ground shims, which are made of C1018 [3/16" thick]. The ground shims are in contact with 316 stainless laminant shims above, and below it are sole plates made up of A36 steel. Obviously, some galvanic reaction due to the dissimilar metals is occurring. The simplest solution would be to apply some treatment to these metals to discourage the galvanic corrosion. I'd like to know what treatments are available out in industry.

Benjamin Saldua
- Pasadena, California, USA


Don't know anything about the galling in that application, but cadmium (very soft, sacrificial against steel) or electroless nickel ( specify hardness, barrier against corrosion) has been used on steel. Silver and other bearing materials can also be applied.

tom pullizzi portrait
Tom Pullizzi
Falls Township, Pennsylvania


Galvanic corrosion is probably not a big problem here. The C1018 and A36 steels are nearly identical in composition and certainly will not be a galvanic corrosion couple. There is a potential difference between the two steels and the stainless steels, but the passive nature of the stainless will typically minimize galvanic corrosion in couples with stainless steel.

The corrosion that you are seeing is most likely general corrosion of the exposed steel, or possibly wear or fretting corrosion. Tom has made good suggestions. Zinc plating may be effective if the general corrosion is the problem. A better diagnosis of the corrosion root cause and service conditions are needed to make a reliable choice.

larry hanke
Larry Hanke
Minneapolis, Minnesota

If you have a question in mind which seems off topic, please Search the Site

ADD a Comment to THIS thread START a NEW threadView CURRENT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2018, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.