Anticorrosive properties enhancement by means of phosphate pigments in an epoxy 2k coating. Assessment by NSS and ACET

• Anticorrosive phosphate pigments were incorporated in an epoxy coating on steel.
• Corrosion resistance is correlated to coating formulation experimentally.
• The optimum anticorrosive pigment type and content were determined by ACET and NSS.

The effect of the addition of anticorrosive phosphate pigments (different types and quantities), standard zinc phosphate and organophilized zinc molybdate phosphate, on the corrosion resistance properties of epoxy coating on cold rolled steel has been investigated by means of two different techniques: a traditional one as salt spray (NSS) and an electrochemical one as the accelerated cyclic electrochemical test (ACET). The optimum anticorrosive phosphate pigment type and its content, that gave the best performance in this epoxy system, were determined. The results offered by each one of the techniques were quite similar, with the advantage that the ACET offered the results in a very short time (24 h) compared to salt spray test.