Recycled Steel Abrasive Grit. Evaluation of Rounding and its Effects on Adhesion.

摘要

The use of recycled metallic abrasives (e.g., steel grit) is becoming more common on U.S. Army Corps of Engineers (COE) projects for preparation of steel surfaces prior to application of thermal-sprayed metallic and liquid- applied coatings. The angularity of the resulting surface roughness is critical to the adhesion of the thermal-sprayed coatings, and enhances the adhesion of liquid-applied coatings. There are no established field methods that a COE inspector can use to evaluate the angularity of the abrasive or the angularity of the surface after abrasive blast cleaning has been performed. The objectives of this research were to determine the effect that the recycling of metallic abrasive has on the adhesion thermal-spray (zinc/aluminum 85/15) and liquid- applied epoxy zinc-rich coatings, and to recommend an approach that can be used to generate industry standards for recycled abrasive. The data may also be helpful in developing field inspection methods for surface and abrasive angularity that can be used to verify proper surface preparation.