Quality assessment of zinc coatings applied by selected methods

Abstract

Purpose: This article presents the problem of corrosion phenomena occurring on steel products, which contributes significantly to the shortening of safe service life. One method of corrosion protection is the application of metal coatings. The most commonly used zinc coatings are described, along with two methods of their application: the galvanizing bath method and the lamellar method. Design/methodology/approach: Coatings were made on the S195 steel specimens in different process variations. Weight, hardness and thickness, as well as surface defects, were used as criteria for assessing the quality of the coatings. Findings: It was found that the process in the galvanizing bath can produce untight coatings with defects. On the other hand, the coatings applied by the lamellar method, were characterized by better aesthetics, lower weight and thickness compared to galvanic coatings, higher hardness compared to galvanic coatings, and uniformly covered the material without discontinuities in the structure that could impair durability. Originality/value: The research clearly indicated the directions of application of the analyzed galvanic and lamellar coatings. The application of coatings is justified in the use of products exposed to corrosive agents. In terms of decorative qualities, more favourable results were obtained on the specimens with lamellar coatings, as these coatings had a silvery colour and an aesthetically pleasing sheen compared to the galvanic coatings. Due to the characteristics of the coatings, galvanic coatings can be used on parts that are operated in harsh environments, while lamellar coatings can be recommended for products that are required to have a low weight change and certain aesthetics Keywords: galvanizing, galvanic coatings, lamellar coatings, coatings quality. Category of the paper: research paper.