Sacrificial Anode in Steam Chest Molding

This probably isn't much help: Zinc is typically used with iron, of course; zinc is the coating for galvanized steel. Magnesium is often used as the sacrificial anode in water heaters. Maybe a targeted search for either of those materials as sacrificial anodes would yield something useful.

I think USB has it right. The type of corrosion this protects from is called "galvanic corrosion" caused by dissimilar metals in contact and covered with some type of conductive fluid (generally water). To protect from it, simply bolt a chunk of zinc to the inside in a spot that will stay submerged in the cooling water.

The zinc will corrode instead of your equipment. Make sure to check it periodically to see if it needs to be replaced (start with once every 6 months or so and adjust the frequency based on the results).

I will keep researching, specifically zinc, thank you very much. This seems way too simple, but maybe a blind hog does find an occasional acorn.

Just bolt a slug of zinc in there and it is all better. Shazaaam!

It does seem overly simple doesn't it? That's part of the beauty of it.

There are other systems out there that are more complex using an "active" corrosion protection scheme with impressed currents and such. The zinc is a passive style that because of its simplicity, low cost, and high effectiveness has stood the test of time. I'm sure if you google it you'll find a wealth of info on it.

Confirm with an accurate digital voltmeter in the mili-volts domain the quantum of un-desirable volts and the direction of current flow under various process conditions, you can connect a dc source (battery) in reverse polarity with an adjustable series resistor to nullify that flow.

Once confirmed experimentally you may buy any of the commercial impressed protection systems.

Do realize that the type of corrosion you are referring to requires weak electrolyte (like sub soil salts or sea water) and essentially Oxygen as well. Your process I assume is in vacuum (oxygen is missing) however cleaning of chemical residues from metal with any industrial cleaner / steam / water jet would be actually what you need.

So if we place a zinc anode into our steam chests, I assume we need to create a good contact surface and bolt it in tight. Is it a good idea to weigh this puppy periodically to see if it is working or is it usually obvious?

In the meantime, when we return to production after the first of the year, we will try to measure voltage between the metals. Should be interesting.

Thanks for the help!

If it is galvanic corrosion (which is what it sounds like to me), the zinc will very noticeably corrode. In my experience weighing won't be necessary, it'll be obvious.

No need to weigh the sacrificial zinc electrode, sharp edges of electrode deform and are clearly visible to the naked eye.