Why will form the different sizes of packaging steel strip production zinc flower

Why will form the different size of the packaging steel strip production zinc flower clotting properly, if zinc galvanizing solution without people spend promote element, the coating is in spontaneous state of cooling crystallization, number of crystal nucleus can be formed, which grows in size small spangles, almost invisible to the naked eye, like a flower without zinc, the so called no zinc products. If in zinc plating solution to join the spangles promote elements such as lead, antimony, they will hinder the formation of crystal nucleus can have only a few embryos grow crystal nucleus, so the final grain size is larger, the zinc flower is bigger, also is the big zinc products. When zinc flower crystallization, lead and antimony will be exclusive to the grain boundary, after long time use black change will happen, and oxidation corrosion from the grain boundary. So big zinc flower, although appearance beautiful, & other; Couldn't use & throughout; Abroad, corrosion resistance, early in the 1970 s it has eliminated the big zinc products. If in zinc plating solution while the spangles promote element, but if under the action of external force to a large number of crystal nucleus formation, after the crystallization of zinc flower size is small, forming small zinc products. The common small zinc production process are: ( 1) Without solidification atomization on the coating of water, make coating rapid cooling, thus forming a large number of crystal nucleus. ( 2) Without solidification of spray coating on the surface of zinc powder, the zinc powder can be external crystal nucleus, the zinc liquid on the zinc powder crystal grew up into smaller flowers of zinc. ( 3) At the end of the annealing furnace factory ammonia, ammonia condensation on the surface of steel strip, the formation of tiny particle, the particle will also be a crystallization of external crystal nucleus, on which the zinc crystals grow up into smaller flowers.