Corrosion protection process

Abstract

A process for the protection of stainless surface from corrosion by a hypohalite-containing composition, the process comprising:- (a) contacting the surface with a composition comprising hydrogen peroxide; and (b) contacting the surface with the hypohalite-containing composition.

1 . A process for the protection of stainless surface from corrosion by a hypohalite-containing composition, the process comprising: 
 (a) contacting the surface with a composition comprising hydrogen peroxide; and    (b) contacting the surface with the hypohalite-containing composition.    
     
     
         2 . A process according to  claim 1 , wherein during step (a), the surface is sprayed with said hydrogen peroxide composition.  
     
     
         3 . A process according to  claim 1 , wherein the surface is an internal surface of a vessel filled with the hydrogen peroxide composition.  
     
     
         4 . A composition according to any preceding claim, wherein the hypohalite-containing composition further comprises an alkali metal silicate.  
     
     
         5 . A process according to  claim 4 , wherein the alkali metal silicate constitutes from 0.01% to 5%, preferably from 0.1% to 1% by weight of the hypohalite-containing composition.  
     
     
         6 . A process according to any preceding claim, wherein the hydrogen peroxide composition comprises from 0.1% to 8-10%, preferably from 1% to 5% by weight of hydrogen peroxide.  
     
     
         7 . A process according to  claim 6 , wherein the surfactant system comprises from 0.1% to 5%, preferably from 1% to 5% of the composition by weight of hydrogen peroxide, from 0.01% to 1%, preferably from 0.1% to 1% by weight of anionic surfactant and from 0.1% to 10%, preferably from 1% to 5% by weight of nonionic surfactant.  
     
     
         8 . Use of a hydrogen peroxide solution to passivate a stainless steel surface, prior to exposure of the surface to a composition containing an alkali metal hypochlorite.