Causes of zinc removal in hot rolled strip
The base plate is coated with an iron oxide layer, which proves that the substrate in the annealing furnace has not been completely reduced to the spongy pure iron required for galvanizing.
The residual impurity particles on the substrate surface are not removed before immersion into the zinc pot, which affects the adhesion of the zinc layer.
The Al content in the alloy layer is little, and the Fe2Al5 alloy layer which is decisive to the adhesion of the zinc layer is not generated, or the alloy layer is damaged by the excessive growth of the iron zinc alloy layer.
