What method does caster galvanize have?
As we all know, for caster galvanized we all know is actually in caster alloy surface plating a layer of zinc is mainly a beautiful, anti-rust effect of a kind of surface treatment technology. But for caster galvanized method is also there are many kinds of galvanized methods used in different places. The following universal wheel to introduce caster galvanized several methods.
1, cyanide galvanized
Due to the extremely toxic nature of cyanide (CN), the environmental protection has put forward strict restrictions on the use of cyanide in electrogalvanization of caster metal parts, and continuously promoted the development of electrogalvanization bath system for reducing cyanide and replacing cyanide caster metal parts. Low - cyanide (micro - cyanide) caster hardware parts of the plating solution. Using this technology caster hardware parts of electroplating product quality, especially color plating after passivation can be very good to maintain the color.
2, zincate galvanized
Zincate zinc plating process is evolved from cyanide zinc plating. At present, there are two major domestic factions:
(1) "DPE" series of wuhan material protection institute
(2) "DE" series of broadcasting institute
Both of these are alkaline additive zincate zinc plating; The PH value is 12.5~13. The lattice structure of the coating is columnar with good corrosion resistance.
Typical formula :NaOH--110~120g/l; ZnO - 11 ~ 12 g/l; 94-5 ~ 7 g/l. For the product code 94 is "DPE - Ⅱ" and the combination of ethanolamine.
Note: the product out of the groove - > wash - > after the light (nitric acid and hydrochloric acid) - > wash - > passivation - > washing - > washing - > hot dry - > drying - > aging treatment (oven within 80 ~ 90 oc).
3, chloride galvanized
Chloride zinc plating process in the caster part of the metal plating industry widely used in the proportion of up to 40%. After passivation (blue white) can be zinc instead of chromium (comparable to chromium plating), especially after the addition of water-soluble varnish, it is difficult for the layman to distinguish galvanized or chrome plating. This process is suitable for white passivation (blue white, silver white). When the customer has no special requirements, it is best to choose silver passivation (color and luster remain relatively stable).
Typical formula: KCl--180~220g/l; ZnCl - 65 ~ 75 g/l; H3BO3--25~30g/l(buffer); The PH value of 5 ~ 5.5; Ci-87 --15~20g/l(brightener).
4, sulfate galvanized
Sulfate zinc plating process is suitable for continuous plating (wire, strip, simple, large and coarse parts) with low cost.
Typical formula: ZnSO4--300~500g/l; H3BO3-25 ~ 30 g/l; PH value: 4.5 ~ 5.5; Sulfur zinc --15~20g/l(brightener).