HOT-DIP COATING OF FERROUS STRANDS

摘要

In hot-dip coating a ferrous metal strand with an aluminium/zinc alloy or like metallic coating medium, the strand is traversed from a furnace to a "galvanising" bath, through a duct terminating in a hood which dips into the bath. While the strand is in the duct and the hood it is subjected to a gaseous reducing environment. The gas consists of N2 and may have as much as 15% of hydrogen in it. The temperature of the gas may be ambient temperatre. The pressure of the gas is just great enough to establish a plenum in the duct so that it may diffuse into the hood and there be quiescent and maintained substantially constant in quantity and composition.