Towards a dependable TEM characterization of hot-dip galvanized steels with low and high Si content

Designing Advanced High-Strength Steels assumes fine-tuning of alloying elements to enhance performance properties. This affects the kinetics Fe-Zn interaction during further galvannealing. A key role here belongs inhibition layer at steel/coating interface. Applying mutually-reinforcing TEM techniques, we traced evolution Zn-Fe phases in low- and high-Si steels It has been shown that conventional room temperature Ga FIB for sample preparation is applicable only annealed low-Si steel, a coating which comprises equilibrium compounds. The were validated via electron microscopy diffraction methods. In contrast, even relatively long annealing steel was not sufficient form stable pointing hampering interphase reactions. As-galvanized specimens contain almost pure Zn are affected by eutectic reaction preparation. Thus, low-temperature applied reliable Zn-coated We refined with HRTEM structures specific grades. While typical Fe2Al5-xZnx interface found samples, ones formation quite Si-Mn mixed oxide membrane, drastically hinders Fe-Al reaction, disclosed.