1、Principle

Because zinc in dry air is not easy to change, and in the humid air, the surface can generate a very dense zinc carbonate film, this film can protect the internal no longer subject to corrosion. And when some reason to make the plating damage and reveal not too large base, zinc and steel substrate to form a microcell, so that the fastener substrate to become the cathode and protected. Widely used in automotive transportation and other industries, but the need for trivalent chromium passivation layer, zinc-nickel alloy plating closed coatings to reduce the hexavalent chromium passivation harmful and toxic layer.

2、Performance characteristics

Zinc plating layer is thicker, the crystallization is meticulous, uniform and non-porous, good corrosion resistance; electroplating zinc layer is pure, corrosion in acid, alkali and other mists slower, can protect the fastening of the sand pieces of the substrate, zinc plating layer passivated by chromic acid after the formation of white, colorful, military green, etc., beautiful and generous with a certain degree of decorativeness, due to the zinc plating layer has a good ductility, so it can be cold-charged, rolled, bent and other kinds of molding and do not damage the Galvanized layer.

3、Application scope

Electro-galvanizing is involved in an increasingly wide range of fields, fasteners products have been used throughout the machinery manufacturing, making galvanized hook mesh, electronics, instruments, chemical industry, transportation, etc. in the national economy is of great significance.

1、Principle

Hot-dip zinc layer is zinc in liquid state, formed in three steps, the iron base surface is dissolved by the zinc liquid to form zinc, iron alloy phase layer; alloy layer of zinc ions further diffusion to the matrix to form zinc, iron mutual solubility layer; alloy layer wrapped around the surface of the zinc layer.

2、Performance characteristics

With a thick dense pure zinc layer covering the surface of steel fasteners, it can avoid the steel substrate and any corrosive solution contact, protect the steel fastener substrate from corrosion. In the general atmosphere, the surface of the zinc layer forms a very thin and dense zinc oxide layer surface. It is very difficult to dissolve in water, so the steel fastener matrix plays a certain protective role. If zinc oxide and other components of the atmosphere to generate insoluble zinc salt, the anti-corrosion effect is more ideal; with zinc - iron alloy layer, combined with dense, in the oceanic salt spray atmosphere and industrial atmosphere in the performance of corrosion resistance; due to the combination of solid, zinc - iron mutual solubility, with a strong wear resistance; due to the zinc has a good ductility, the alloy layer attached to the steel substrate. Because zinc has good ductility, its alloy layer is firmly attached to the steel substrate, so hot-dip galvanizing can be cold punching, rolling, drawing, bending and other molding processes, without damage to the plating layer; hot-dip galvanizing of steel structural parts is equivalent to an annealing treatment, which improves the mechanical properties of the steel substrate and eliminates the stress of steel molding and welding, which is conducive to the steel structural parts of the turning process; the surface of the hot-dip galvanizing of the fasteners after the surface of the bright and beautiful; the zinc layer is a layer of pure zinc in the hot-dip galvanizing The pure zinc layer is a plastic layer of hot-dip zinc galvanized layer, its nature is basically close to pure zinc, has good ductility.

3、Application range

This plating method is especially suitable for all kinds of strong acid, alkali mist and other strong corrosive environment.