Inorganic conversion coatings for ferrous substrate
AssigneeRutgers, The State University
InventorsRichard E. Riman, Seung-Beom Cho
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Abstract
The formation of passivation coatings on ferrous substrates is disclosed by heating the substrate in an aqueous 1.0 to 6.0 M basic metal hydroxide treatment bath containing SiO.sub.2 and a water-soluble glycol, at a temperature that is effective to form a passivation coating on the substrate until the passivation coating is formed thereon, wherein the treatment bath contains from about 0.25 to about 1.0 moles of SiO.sub.2 per liter of glycol and water.
Claims20
A method for forming a passivation coating on a ferrous substrate, comprising heating said ferrous substrate in an aqueous treatment bath comprising a basic metal hydroxide, SiO.sub.2, and a water-soluble glycol, at a temperature above about 160.degree. C. so that said basic metal hydroxide and said water-soluble glycol in said treatment bath oxidize said ferrous substrate, whereby said passivation coating is formed thereon at a temperature less than the temperature at which said passivation coating forms in the absence of said water soluble glycol, wherein said treatment bath comprises from about 0.25 to about 1.0 mole of SiO.sub.2 per liter of glycol and water.
A method for forming a passivation coating on a ferrous substrate, comprising heating said ferrous substrate in an aqueous 1.0 to 6.0 M basic metal hydroxide treatment bath comprising the basic metal hydroxide, SiO.sub.2, and a water-soluble glycol, at a temperature above about 160.degree. C. so that said basic metal hydroxide and said water-soluble glycol in said treatment bath oxidize said ferrous substrate, whereby said passivation coating is formed thereon at a temperature less than the temperature at which said passivation coating forms in the absence of said water soluble glycol, wherein said treatment bath comprises from about 0.25 to about 1.0 mole of SiO.sub.2 per liter of glycol and water.
A method for forming a passivation coating on a ferrous substrate, comprising heating said ferrous substrate in an aqueous treatment bath comprising a basic metal hydroxide, SiO.sub.2, and 1,4-butanediol or ethylene glycol, at a temperature that is effective to form a passivation coating on said substrate until said passivation coating is formed thereon, wherein said treatment bath comprises from about 0.25 to about 1.0 mole of SiO.sub.2 per liter of 1,4-butanediol or ethylene glycol.
Dependencies are inferred from the claim text.