Evaluation of the Phases Present in the Zinc Coating Obtained on the Ductile Cast Iron Substrate in the Bath with the Addition of Ti

This paper presents the effect of the addition of Ti to the zinc bath. Hot-Dip Galvanizing was carried out on a machined ductile cast iron substrate. The process was carried out at 550°C. Experimental baths A, B and C contained 0.01%, 0.05% and 0.1%Ti, respectively. Metallographic samples were prepared to reveal the microstructure of the coatings. Thickness measurements of the obtained coatings were carried out, and graphs of the approximate crystallization kinetics of the zinc coating were prepared. High-temperature galvanization carried out on the treated surface led to the release of graphite beads from the metal matrix and their diffusion into the coating. This phenomenon can have an adverse effect on the continuity of the coating and its adhesion to the substrate. Crystallization of the δ phase was observed in the coating, and at longer immersion times – a mixture of two-phase δ1 and η phases. With increasing Ti content in the bath, a deterioration in the casting properties of the bath was observed.