Wetting force and contact angle measurements to evaluate the influence of zinc bath metallurgy on the galvanizability of high-manganese-alloyed steel

The present investigation aimed to evaluate the influence of zinc bath metallurgy on the hotdip galvanizing of a high-manganese-alloyed steel (commercial grade X-IP 1000). Wetting force and contact angle measurements were carried out by the Wilhelmy plate methodology to assess zinc bath compositions. The Wilhelmy plate methodology was particularly suitable for both quantifying liquid zinc wetting and producing coated samples to be characterized. The aluminium content of the zinc bath varied between 0.05 and 1.10 wt % and manganese as well as silicon was additionally added to the bath composition. Best wetting occurred with aluminium contents which are typical for industrial galvanizing baths (0.12–0.22 wt %). But zinc wetting and wetting reactivity decreased with increasing aluminium content > 0.30 wt %. Hence, aluminothermic MnO reduction seems to be ineffective in the present case. Wetting results might be further improved by adding manganese or silicon to the zinc bath due to an improved wetting reaction. However, the formation of additional phases in the coating has to be considered with regard to technical use.