Evaluation of Effect of Ti Addition to Zinc Bath on Kinetics of Growth of Alloy Layer Formed in Process of Hot-Dip Galvanisation on Steel Substrate

Faced with the raw material crisis in Zn resources, researchers are facing the challenge of developing technology for producing zinc coatings that are thinner than those that have been produced to date. This would make it possible to reduce Zn consumption in the hot-dip galvanisation process. The study included an experiment that involved dip galvanising steel samples in baths of different Ti concentrations; this process was carried out at 450 °C and 550 °C. The use of this additive made it possible to reduce the growth of the alloy layer in the obtained zinc coatings. Using an optical microscope, observations were made of the microstructures of the resulting coatings, which made it possible to determine the thickness of the alloy layer in the coating. Thanks to the use of scanning electron microscopy with EDS analysis, however, it was possible to plot the chemical composition of the studied coatings and accurately observe the morphology of the formed phases. An intermetallic Zn-Fe-Ti phase was observed in the coatings formed in a Ti-added bath, which can affect the growth inhibition of the alloy layer in the zinc coating.