The Effects of Various Factors for Cathodic Delamination of Polyurethane Coated Steel Pipe

Abstract

The effects of some factors such as electric potential, kinds of cation in aqueous solution, dissolved oxygen, temeprature and coating thickness for cathodic delamination of polyurethane coated steel pipe were investigated. The cathodic delamination kinetics of polyurethane coated steel were affected by diffused cation　along　the　adhesion　interface　to　delamination　front　and　diffused　oxygen　through　coating　layer　to　delamination　front.　In　order　to　explain　this,　the　electric　neutral　conditions　under　polyurethane　coating　layer　were　newly　proposed,　and　the　cathodic　delamination　model　for　polyurethane　coated　steel　which　can　explain　an　experiment　result　qualitatively　was　proposed.