Paint Blistering Mechanism of Steel Painted with Paint System Containing Inorganic Zinc Rich Paint

Abstract

The paint blistering mechanism of steel painted with paint system containing inorganic zinc rich paint （ZRP） was investigated. As a result of observing the appearance and cross section of the corroded painted steel with or without ZRP, the paint blistering form changed from blister to pushing up of the paint due to generation and growth of Fe corrosion products with the progress of corrosion. ZRP corrodes prior to the paint blistering to form Zn corrosion products, reducing the cathode reaction （oxygen reduction） under paint and suppressing blister. In addition, ZRP reduces the Fe corrosion reaction at the tip of the paint blistering and makes fine Fe₃O₄ particles. These effects suppress the formation and growth of Fe corrosion products and suppress the paint blistering.