Effect of Processing Factors and Ambient Conditions on Phytic Acid Conversion Coating on Zinc by Atmospheric Corrosion Monitor Sensor

Both the effect of forming conditions on corrosion resistance of phytic acid conversion coating on zinc in air and the influence of ambient factors (temperature and relative humidity) on service of conversion coating were studied by SEM, EDS, ACM and SKP. Zinc-graphite ACM sensors and zinc plates were treated with phytic acid solution at different processing time and pH values. The results showed that longer processing time and alkalinity phytic acid solution weaken the corrosion resistance of treated zinc. Self-assembled monolayer of zinc phytate provided the best protection. The corrosion resistance of conversion coating with phytic acid solution was reduced when the ambient temperature or relative humidity is high values, which due to the zinc phytate bond strength with zinc matrix and co-adoption water on it.