Corrosion protection of carbon steel using zirconium oxide/silane pretreatment and powder coating

Abstract

A new generation of metal pretreatments based on nanosized zirconiurn oxide or ogranosilane film has been investigated recently as an altemative method to phosphatation. In this paper, ZrO2/silane composite film on carbon steel was prepared and characterized by field emission scanning electron microscopy, energy dispersive X-ray spectrum and electrochemical measurements. The effect of ZrO2/silane surface treatment on the corrosion protection properties of powder coating was studied by spraying salt and adhesion measurement. The results showed that ZrO2 was rapidly precipitated on the steel surface in the first minute of immersion. ZrO2/silane film was formed after 4 minutes of immersion and gave the best protective property. Powder coating on carbon steel with ZrO2/silane pretreatment had equivalent protection performance like the powder coating with phosphate pretreatment. Besides of this, higher dryness and better wet adhesive value of ZrO2/silane pretreatment were comparable to those of phosphate pretreatment.