Study of an alternative phosphate sealer for replacement of hexavalent chromium

►The niobium and ammonium solution provided the highest corrosion of the phosphated samples at pH 8.0. ►A niobium and ammonium solution showed better passivating/sealing properties than Cr6+. ►Sealing/passivating treatment with Nb provided good adhesion to a polyester based paint. ►Niobium and ammonium oxalate can replace Cr6+ in passivation/sealing treatments.