The Use of Chromium and Chromium (III) Oxide PVD Coatings to Resist the Corrosion Driven Coating Delamination of Organically Coated Packaging Steel

N Wint,H N Mcmurray,A C A Devooys,D J Warren

doi:10.1149/1945-7111/abc360

Abstract

This paper describes a systematic study into the role of chromium and chromium (III) oxide thickness in preventing corrosion driven coating disbondment of organically coated packaging steel. A graded wedge of chromium and chromium (III) oxide is applied to steel using physical vapour deposition (PVD). A polyvinyl butyral (PVB) overcoat is applied and corrosion is initiated from an artificial defect using NaCl. Scanning Kelvin probe (SKP) potentiometry is used to monitor coating delamination. Wedge thickness variation allows for high throughput investigations into the effect of both metallic chromium and chromium (III) oxide thickness, on coating disbondment rate. A linear reciprocal relationship is observed between chromium metal thickness and disbondment rate. Increasing chromium (III) oxide thickness (applied over chromium metal) results in a decrease in delamination rate. This work highlights the ability of PVD to produce chromium/chromium (III) oxide corrosion resistant coatings to use as alternatives to hexavalent chromium-based systems.

Highlights

The Use of Chromium and Chromium (III) Oxide physical vapour deposition (PVD) Coatings to Resist the Corrosion Driven Coating Delamination of Organically Coated Packaging Steel
Chromium based coatings are typically applied to provide corrosion resistance to packaging steel substrates, which have been shown to corrode in the case that that they are exposed during the can making deformation process.[19]
This work has shown that it is possible to produce a chromium and chromium/chromium (III) oxide coating combinatorial library on a single substrate through physical vapour deposition (PVD) of a “wedge” onto a steel substrate. This allows for a rapid, parallel investigation into the role of coating thickness in preventing the corrosion driven coating disbondment of organic coatings from packaging steel, using SKP

Summary

Introduction

The Use of Chromium and Chromium (III) Oxide PVD Coatings to Resist the Corrosion Driven Coating Delamination of Organically Coated Packaging Steel. The intention of the current work is to build upon the findings obtained that showed that corrosion driven cathodic disbondment of a PVB coating, from production line chromium (III) metal-oxide-carbide coated steel, decreased with increased chromium oxide thickness.

Results

Conclusion