A Study to Examine the Effect of the Phosphate Coating Process on Adhesion and Corrosion Resistance in Structural Steels
Makaleler > Tam Makale · 2025
Yazarlar: Kader Sever, Nilay ÇÖMEZ, Can Çivi, Handenur Karaoğlu
International Journal of Computational and Experimental Science and Engineering, Uluslararası, Scopus, 2025, cilt 11
DOI: 10.22399/ijcesen.715
Özet
Industrial washing and drying machines are systems that operate in high-temperature and humid environments, which can therefore be considered aggressive in terms of corrosion. Stainless steel materials to be used in the body structures of these systems are the most important solution in this regard due to their superior corrosion resistance properties. However, due to the low initial investment cost, structural steels, especially from the non-alloy steel group with low carbon content, are widely used in the sector as an alternative to stainless steel in machine and system bodies by increasing the corrosion resistance by applying paint. However, it is an important necessity to apply some additional surface treatments to low carbon steel to supply protection against aggressive corrosive environments. Phosphate coating by spraying is a widely applied industrial method to increase the adhesion of metal surfaces to paint and their resistance to corrosion. A corrosion reaction occurs on the metal surface, which has the ability to react with an acidic phosphate coating solution. Subsequently, the pH rise occurs as a result of neutralization in the region of the solution close to the metal surface. The soluble phosphate form becomes insoluble in the rising pH region, and phosphate coating begins because of crystallization. This etching and coating process continues until the entire surface is covered with a phosphate layer. The coating process ends with the etching reaction as soon as the phosphating solution no longer has direct contact with the metal surface. Within the scope of this study, the corrosion behaviors of two different stainless-steel materials (AISI 304 and AISI 316 ) and a St-37 (S235JR) structural steel material, which was painted directly, painted after phosphate coated and painted+phosphate coated were examined. The aim of the study is to reveal the substitutability of structural steel material to stainless steel materials in terms of corrosion properties. Contact angle measurements, cross-cut test, microhardness and surface roughness value of the samples were analyzed. The lowest corrosion resistance was obtained with phosphate coated, while the highest corrosion resistance was observed in the phosphate coated+painted sample.