The influence of hot-dip galvanized steel surface pretreatment on the adhesion of epoxy coating

Abstract

The influence of hot-dip galvanized steel surface pretreatment on the adhesion of epoxy cataphoretic coating was investigated. Several passive films were formed on hot-dip galvanized steel (phosphate, chromate and oxide). The dry and wet adhesion of epoxy coating were measured by a standard pull-off method. Sorption characteristics were determined by gravimetric measurements. The surface roughness of galvanized steel surfaces pretreated by different methods was determined, as well as the wettability of the metal surface by polymer solution. The adhesion of epoxy coated hot-dip galvanized steel, pretreated by different methods, was investigated in 3 % NaCl.

U radu je ispitivana modifikacija površine pocinkovanog čelika na adheziju epoksidne kataforetske prevlake. Površina pocinkovanog čelika je modifikovana formiranjem pasivnog filma (fosfatnog, hromatnog i oksidnog) i praćena je promena adhezije epoksidne kataforetske prevlake na njoj, pre i tokom delovanja korozionog agensa. Sorpcione karakteristike su određivane gravimetrijskim merenjima. Ispitivana je hrapavost modifikovanih površina pocinkovanog čelika, kao i njihova kvašljivost emulzijom epoksidne smole u vodi. Adhezija epoksidih prevlaka na modifikovnom pocinkovanom čeliku je ispitivana u rastvoru 3 mas. % NaCl.