Chemical removal of a chromium oxide coating from an article

• Main Author: BROOKS, WILLIAM CLARKE
• Format: Patent
• Language: English; French; German
• Published: 19.05.2004
• Edition: 7
• Subjects: BLASTING; CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLEANING OR DEGREASING OF METALLIC MATERIAL BY CHEMICALMETHODS OTHER THAN ELECTROLYSIS; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; HEATING; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; LIGHTING; MECHANICAL ENGINEERING; METALLURGY; NON-POSITIVE DISPLACEMENT PUMPS; POSITIVE DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; WEAPONS

A chromium oxide coating is removed from a surface of an article by cleaning the article in an alkaline degreasing/rust removal solution at a degreasing/rust removal temperature of from about 180 DEG F to about 200 DEG F, scale conditioning the article in an alkaline permanganate conditioning solution at a scale-conditioning temperature of from about 160 DEG F to about 200 DEG F and contacting the article with an acidic stripping solution comprising hydrochloric acid and an etching inhibitor at a stripping temperature of from about 130 DEG F to about 140 DEG F.