The Influence of Cutting Metal Elements on the Structure and Corrosion Resistance of the Zn Coating

The aim of the research was the indication of the causes of a difference in thickness of the zinc coating on the surface shaped by plasma cutting. The research was focused on fittings for overhead power lines - a double eyes links made of steel S355J2. The prepared materials were cut by plasma. Then, links were subjected to mechanical treatment (shot-blasting) and chemical treatment (pickling, rinsing and fluxing). The hot-dip galvanizing process was performed in industrial conditions by applying the constant temperature equal to 457°C, and a dipping time equal to 150 s. The research was conducted on the link’s flat surface (after rolling) and the side surface (after cutting). The (Zn) - coating morphologies and sub-layer thicknesses were evaluated on the basis of metallographic analysis and corrosion tests (acc. to EN ISO 9227). The correlation between the results of corrosion test and coatings morphology was determined.The observed changes are closely related to the outer layer steel structure (HAZ) which subsequently influences the mechanism and zinc coating growth kinetics