Characterisation and corrosion behaviour of WAP coating on 300M steel

In this work, a special water-based aluminium phosphate (WAP) coating containing primer and finishing layers was applied on 300M steel. The curing temperature of the primer layer was about 250°C and that of the finishing layer was 200°C. The aluminium phosphate binder in both primer and finishing layers was barely crystallised, and the most effective binding phases were Al and aluminium phosphate. WAP coating showed the formation of corrosion...