Electrochemical corrosion protection of stainless steel bleach plant washers
AssigneePulp and Paper Research Institute of Canada
InventorsAndrew Garner, Laurent H. Laliberte
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Abstract
A method is provided herein for the electrochemical corrosion protection of a partly submersed, rotating, stainless steel drum in a vat containing a corrosive, oxidizing, chloride-containing bleach liquor. The method comprises the step of impressing a protection potential to the stainless steel drum at a predetermined voltage in the range of -600 to +400 mV.sub.Ag/AgCl. This predetermined voltage is sufficiently low to draw the stainless steel into a passive corrosion protection zone. However, that voltage is not sufficiently low to draw the stainless steel into a zone of uniform corrosion. Specific means for the placement of the anode in the vat are also provided.
Claims4
A method of electrochemically protecting by cathodic polarization a partly submersed, rotating, stainless steel drum in a vat containing a corrosive oxidizing chloride containing bleach liquor which comprises impressing a protection potential to said stainless steel drum at a predetermined voltage in the range of -600 to +400 mV.sub.Ag/AgCl, said predetermined voltage being sufficiently low to draw said stainless steel into a passive corrosion protection zone but not sufficiently low to draw it into a zone of uniform corrosion.
Dependencies are inferred from the claim text.