Performance of rust converter based in phosphoric and tannic acids

摘要

The role of a rust converter with tannic and phosphoric acids is evaluated for painted and unpainted steel with different corrosion degrees and salts contaminating the rust. The performance of unpainted samples is monitored with impedance and characterized by X-ray, infrared and Raman spectroscopies. Results show long-term action of the converter. For painted samples, loss of adhesion and corrosion spread around a scratch are measured after alternated immersion corrosion test. For rusted samples with high chloride contamination, the converter is harmful. For rusted samples with lower contamination, the influence of the converter on the performance of the painting is not detected.