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Corrosion protection of installed 1018 steel vacuum chambers  

June 6, 2009

I took over the design and implementation of large vacuum chambers made from 1018 or A36.
We are in dry Colorado but corrosion is starting to occur. This is used for a chemical sublimation process with the inside having different concerns from the exterior.
We need to protect the outside including oring surfaces from further rust.
Parkerizing looked promising except for the phosphate which has the potential to stink up the process.
Is there a recommendation for treating these systems with a confomal coating that has a minimal effect on oring sealing surfaces that can be applied, in place, with the chambers at less than 140 deg C.?

Rod Ward
Design Engineer - Denver, Colorado