Galvanized coilï¼ˆÂ sheet/stripï¼‰ is coated with zinc, either by the hot-dipping or electrolytic deposition processes. Zinc coating applied by the hot dip method is normally heavy enough to resist corrosion without additional protective coating. Materials electronically galvanized are not used for corrosion-resistant applications without subsequent chemical treatment and painting, except in mild corrosive conditions, due to the thin coating of zinc.
Spangles cannot be seen on the surface of the steel plate by naked eyes, also called zinc-free plating, which is produced by controlling the chemical composition of zinc liquefaction. Zinc – free steel products can be produced by adding aluminum in zinc solution without addiation of lead, antimony and tin. The process is widely used throughout the world because it allows uniform surfaces to be obtained without additional equipment. It offers superior corrosion resistance and better coating performance, suitable for various purposes of modern industry, is the ideal base plate of color coated sheets.
Normal spangle are those with a diameter of more than 3mm that can be distinguished by the naked eye, also known as large spangle or natural spangle. The best size recognized internationally is 8~12mm.
Minimized spangles is the spangle with diameter 1~2mm. After the hot galvanized sheet came from zinc pot, spray water mist or zinc powder to no solidification of zinc layer, water droplets or zinc powder particles will form a crystallization center, which make the unit area zinc flower number increased and smaller, so galvanized plate surface will form with the naked eye can distinguish small spangle. However, this process often causes uneven zinc bloom and high production costs, so it is not widely used at present.
|Standard: JIS G3302, ASTM A653M/A924M, ASTM A525, DIN1716 EN10327 etc
|Grade: SGCC,SECC,DX51D,DX52D,Q195,Q215,Q235,Q345 etc
|Spangle: Zero spangles, Small spangles, Regular spangles, Large spangles
|Zinc coating: 40-275g/m2
|Processing Service: Bending, Welding, Decoiling, Cutting, Punching
|Delivery Time: 7- 14 Days