CRYSTALLOGRAPHIC STUDY OF HOT DIP GALVANIZED STEEL

With special attention to hetero-epitaxial growth of FeZn13(zeta) crystals precipitated on 99.999% pure iron substrate, we have investigated the reaction between Fe and Zn during hot dip galvanizing. The results obtained are as follows. (1) Hetero-epitaxial growth of zeta crystals on iron substrate is found. (2) The epitaxial growth largely depends on the crystal plane of iron substrate. On(111)-(113)-(313) alpha the epitaxial growth occurs, while on (001)-(101)alphazeta crystals are oriented randomly. (3) FeZn7(delta1) Crystals are often precipitated at the interface between randomly oriented zeta crystals and iron substrate. (4) Zeta has [001]zeta axis as the growing axis and a diamond cross-section surrounded by four {110}zeta planes. (5) The crystallographic relationship between zeta crystal and iron substrate is as follows; (121BAR)[113BAR]alpha//(110) inverted right perpendicular 001 left perpendicular zeta or (211BAR)[113BAR]alpha//(010)[001]zeta.