Enhancement of paint adhesion to cold rolled steel in salt bath by low temperature Ar-H2 plasmas

This study investigates the enhanced adhesion of paint to cold rolled steel (CRS) in salt bath by Ar-H₂ plasmas. It is found that the surface treatment on CRS, prior to painting, by low temperature plasma cleaning with argon-hydrogen plasmas at room temperature (23 °C), can be used for improving the adhesion of paint to CRS in salt bath. The tape test (ASTM 3359 Method) demonstrated this improvement, with a rating of “0” for untreated CRS for aging at a 3.5 wt% NaCl solution for 6 days and “5” for argon-hydrogen plasma-cleaned CRS at certain plasma conditions even for aging at a 3.5 wt% NaCl solution for 6 days. The adhesion performance of paint to CRS in salt bath is highly dependent on the surface characteristics of the CRS and the work of adhesion of paint to CRS.