Accelerated Corrosion Tests in Quality Labels for Powder Coatings on Galvanized Steel-Comparison of Requirements and Experimental Evaluation.

Izabela Kunce,Leszek Komorowski,Agnieszka Królikowska

doi:10.3390/ma14216547

Izabela Kunce, Leszek Komorowski + Show 1 more

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https://doi.org/10.3390/ma14216547

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Journal: Materials	Publication Date: Nov 1, 2021
Citations: 4	License type: CC BY 4.0

Affiliation: Road and Bridge Research Institute

Abstract

Powder coatings are widely applied for corrosion protection of steel, aluminum, and hot dip galvanized steel in a variety of corrosive environments. Powder coatings are subjected to a number of strict laboratory tests to determine their mechanical properties, corrosion resistance, and color stability. Among European quality certificates for powder coatings applied to galvanized steel, the most commonly recognized are GSB-ST and Qualisteelcoat certificates, which also refer to the EN 13438 standard. Certificates of quality for powder coatings are constantly updated according to the latest research results and experience of specialists operating in the field of corrosion protection. This paper presents an experimental evaluation of how the required length of selected accelerated corrosion tests can affect the final assessment of powder coatings. On the example of two powder painting systems: polyester as well as based on epoxy and polyester resins, the paper presents the influence of the time of accelerated corrosion tests: ISO 6270, ISO 9227 (Neutral Salt Spray and Acetic Acid Salt Spray), and ISO 3231 on the protective properties of the coatings. The results of damage assessment according to ISO 4628 have been correlated with the requirements of particular quality specifications. Additionally, based on FTIR (Fourier Transform Infrared Spectroscopy) and EIS (Electrochemical Impedance Spectroscopy) analyses, the influence of the applied corrosion tests on the degradation degree of the coatings studied has been presented. The paper aims to present a tests for those powder coating systems applied to facilities for which the main requirement is corrosion resistance rather than aesthetics.

Highlights

Powder coatings are widely used for anti-corrosion protection of aluminum and steel elements
The paper aims to present a tests for those powder coating systems applied to facilities for which the main requirement is corrosion resistance rather than aesthetics
The limitation in the use of powder coatings is the size of the parts being protected, limited by the size of the furnaces used for curing of thermoset coatings or baths used for preparation of the surface by immersion before painting

Summary

Introduction

Powder coatings are widely used for anti-corrosion protection of aluminum and steel elements. The limitation in the use of powder coatings is the size of the parts being protected, limited by the size of the furnaces used for curing of thermoset coatings or baths used for preparation of the surface by immersion before painting. Due to their high chemical, mechanical, and UV resistance [4], powder coatings are widely used to protect elements and construction that are operated both in external (facades, industrial buildings) and internal (equipment housings) conditions. Powder coatings can be modified to obtain specific functional properties, such as anti-graffiti, anti-bacterial, flame retardant, antistatic, abrasion resistant, or with special visual effects (metallic or wood effect)

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