Low Cost Solar Selective Chromate Conversion Coatings Applied to Stainless Steel Substrates

Abstract

Solar selective surfaces have been produced on austenitic and ferritic stainless steels using an acidic chromate bath at 75°C. These surfaces have been shown to have high humidity resistance and good thermal stability. The conversion coatings can be applied uniformly over large surfaces, even surfaces of nonplanar topography. Complete sets of plating parameters for different grades of stainless steels are presented which may be used for the implementation of this process for the production of low grade heat collecting systems.