Effects of CaO and MgO on Anticorrosive Performance of Aluminum Dihydrogen Tripolyphosphate on Mild Steel

CaO and MgO were used to neutralize aluminum dihydric tripolyphosphate (ADTP) by co-grinding, and the effects of CaO and MgO on anticorrosive performance of ADTP on mild steel were studied. The efficiency of the resulting multicomponent pigments as corrosion inhibitors for mild steel boards in 3.5% w/w NaCl solution was determined by electrochemical measurements. The results showed that the anticorrosive performance depended on the component of the pigments and the feeding order of ADTP, CaO, and MgO in grinding. ADTP/MgO/CaO displayed more high performance than others, which was attributed to the relatively integrated passivating film constructed on the surface of the test board. And the anticorrosion of waterborne epoxy coatings was effective and persistent.