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.