Brief Introduction of Commonly Used Galvanizing Alloy Process
Apr 07,2021
Zinc-based alloys have excellent corrosion resistance. Binary or ternary alloys of zinc and other metals can be obtained by electroplating. Most of the zinc alloy corrosion resistanceBetter than pure zinc, can effectively reduce the coating thickness. Currently used zinc alloys are:Zn-co · zn-co-cr · zn-fe · zn-mn · zn-ni · zn-ti,Zn-A1 and so on. The most noticeable is the Zn-Ni alloy, which has excellent corrosion resistance and low hydrogen brittleness, and may replace zinc andCadmiumPlating.Zn-CoAlloyAppearance likeChromiumIt can be used as a decorative coating.Zn-Fe alloy has better corrosion resistance than zinc, can be phosphated, and has been used for electroplating of steel plates and parts.
1,GalvanizingNickelAlloy
ZincNickelalloyNickel content8% ~ 15% is better. ZincNickelcombinedGold'sThe corrosion resistance and wear resistance of zinc are approximately3~5 times, heat resistance up to 200~250 ℃, weldability and ductility and zinc equivalent, in carbon tool steelmicroscopicThe hardness isHV550 has good bonding force with paint and hydrogen embrittlement is close to zero (embrittlement rate is only 1.5, whileCyanideGalvanized53%, zincateGalvanized78%, bright platingCadmiumFor18%, chloride zinc plating is 46%), the coating toxicity is small, but the lubrication performance is not as good as zinc. It is the ideal generationCadmiumThe coating has been widely used in steel plates, vehicles and household appliances.
toComposition and process conditions of plating solutiondistinguish,ZincNickelThe main types of alloy bath are: chloride type, sulfate type, amino sulfonate type, acetateType, lemonCitrate type, gluconate type, etc. The most widely used is the chloride type and sulfate type.
2,Galvanized iron alloy
containing iron8% ~ 20% zinc-iron alloy has been widely used in the production of tin plate and tin belt, and its corrosion resistance is better than zinc. The corrosion resistance of zinc-iron alloy containing 1% ~ 8% iron is equivalent to or slightly lower than that of pure zinc layer. The high corrosion resistance zinc-iron alloy contains 0.2~0.7 iron, and the 5um coating can be resistant to neutral salt spray test for 2000h after chromate color purification, and its ductility is equivalent to zinc, the plating solution has good dispersion ability and low cost. The coating can be passivated in color, white or black, and can be used for electroplating steel plates and various parts.
3. Galvanized cobalt alloy
Electroplating zinc-cobalt alloy is a relatively new process, the plating system of zinc-cobalt alloy is mainly4 types: chloride type, sulfate type, chloride-sulfate mixed type and alkaline zincate type, research and application is more chloride type. In recent years, the development of alkaline plating solution is fast, and its application is more and more extensive. The zinc-cobalt alloy coating has good corrosion resistance and is also an anodic coating for steel substrates with electrochemical protection. The corrosion resistance of the alloy coating is related to the cobalt content in the coating. With the increase of cobalt content, the corrosion resistance increases, and when the cobalt content exceeds 1%, the improvement of corrosion resistance becomes smaller. Therefore, people from the economy and the maintenance of the plating solution, most of the use of cobalt content of 0.6 to 1% of the zinc-cobalt alloy coating. The neutral salt spray test shows that the red rust time of zinc-cobalt alloy coating is more than two times higher than that of zinc layer with the same thickness. Zinc-cobalt alloys with low cobalt content can also be passivated by chromate, and the corrosion resistance is also greatly improved. Because the cobalt content of this kind of alloy coating is relatively small, the cost is low and the process is simple.
Dazhi Chemical has been committed to the development and research of various electroplating processes. As a leader in the industry, it has also made great achievements in galvanized and zinc alloy products. If interested, welcome friends to discuss together!
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Email: sales@dazhichem.com
Phone/WeChat: 86-18520125168
Address: No.1 Tianyuan East Road, Yonghe Economic Zone, Huangpu District, Guangzhou City
