Method For Removing A Coating From A Component

Abstract

Method for removing coatings which have been applied to components such as turbine blades. After the end of the product life cycle of the turbine blades has been reached, these coatings can be removed to reuse the turbine blades after recoating. The coating, containing in particular chromium oxide compounds is removed via a stripping bath by adding alkanolamine compounds or salts containing such compounds as the inhibitor. These compounds advantageously prevent new chromium oxide compounds from being produced during the stripping of the turbine blades or the chromium oxide compounds present in the coating are removed effectively, so that the chromium oxide compounds cannot have an adverse influence on the removal rate of the stripping process. Advantageously reduced treatment times can thereby be achieved for the stripping process. By adding 2% triethanolamine, the treatment time in hydrochloric acid for example can be reduced to below one hour.

1 - 5 . (canceled) 
     
     
         6 . A method for electrochemically removing a coating containing chromium and/or chromium oxide compounds from a component in which the coated component is introduced into a stripping bath and is removed again after the treatment time has elapsed, an alkanolamine compound or a salt containing such a compound being added to the stripping bath as an inhibitor, characterized in that triethanolamine or one of its salts is added as the inhibitor, the coating being removed from a turbine blade. 
     
     
         7 . The method as claimed in  claim 6 , characterized in that carbonic acids and/or aldehyde compounds and/or unsaturated alcohols are added as further inhibitors. 
     
     
         8 . The method as claimed in  claim 6 , characterized in that the coating is an MCrAlY coating and/or a thermal barrier coating. 
     
     
         9 . The method as claimed in  claim 7 , characterized in that the coating is an MCrAlY coating and/or a thermal barrier coating.