During normal solidification, if no zinc flower promoting element is added in the zinc plating solution, the coating is cooled and crystallized in a spontaneous state, and a large number of product cores can be formed, thus growing into tiny zinc flowers, which are almost invisible to the naked eye, just like no zinc flowers, so it is called no zinc flowers.
If the zinc flowers such as lead and keto are added to the zinc solution to promote the formation of the product nucleus, they will hinder the formation of the product nucleus. There can only be a small amount of the product nucleus of the product embryo.Lead or brocade will be excluded from the boundary of large zinc flowers, and will be blackened after long use, and begin to oxidize and corrode from the grain boundary.Therefore, although the large zinc flower is beautiful in appearance, it is useless to look at it seriously, and its corrosion resistance is affected. As early as the 1970s, foreign countries had already eliminated the large zinc flower products.
If a large number of product cores can be formed under the action of external forces, even if the zinc flower promotion elements are added in the zinc plating solution, the size of the zinc flower after the product is small, then the small zinc flower products are formed.Common processes include:
(1) spray physicochemical water on the unsolidified coating to cool the coating rapidly, thus forming a large number of crystal nuclei.
(2) spray zinc powder on the surface of the unsolidified coating. These zinc powder can become foreign crystal nucleus and make the zinc liquid crystallize on these zinc powder to form smaller zinc flowers.
(3) ammonia gas is injected at the end of the annealing furnace, and the ammonia gas is condensed on the surface of the steel belt, forming tiny particle points, which will also become foreign crystal nucleus when crystallizing and crystallize on it to form smaller zinc flowers.