Galvanized steel strip is processed by ordinary steel strip pickling, galvanizing, packaging and other processes. It is widely used because of its good corrosion resistance. It is primarily used in the manufacture of metal products that are cold worked but no longer galvanized. For example: guardrail net peach-shaped columns, light steel keels, sinks, bridges, rolling shutter doors and other metal products.
1. Main uses:
1.General civilian use
Processed into household appliances, such as sinks, reinforced door panels or reinforced kitchen appliances, etc.
2.Construction industry
Roofing, light steel keels, walls, suspended ceilings, water shields, rain jackets, rolling shutter doors, warehouse interior and exterior panels, insulation shells, etc.
3.Household appliances
Strengthen and protect household appliances such as refrigerators, washing machines, showers and vacuum cleaners.
4.Automobile industry
Parts for large cars, trailers, trucks, luggage carts, refrigerated trucks, wipers, garage doors, fenders, fuel tanks, water tanks and more.
5.Industrial
As the base material of stamping materials, it can be used in bicycles, digital products, armored cables, etc.
6.Other aspects
Equipment covers, instrument panels, electrical cabinets, stainless steel office furniture, etc.
2. Main production technology
first stage
The entire roll of steel strip should be pickled to remove rust and dirt and make the surface smooth.
second stage
After pickling, it is cleaned in an aqueous solution of ammonium chloride or zinc chloride or a mixed aqueous solution of ammonium chloride and zinc chloride, and then sent to a hot-dip galvanizing tank for hot-dip galvanizing.
three stages
After the steel strip is galvanized, it can be rolled up and stored in storage. According to customer requirements, the galvanized layer is generally not less than 500g/m2, and any sample is not less than 480g/m2.
What are the causes and solutions for whitishness of galvanized steel strips?
If there is a layer of condensed water on the surface of the zinc coating, it will turn into a corrosive aqueous solution after interacting with chemical gases such as oxygen, carbon dioxide, hydrocarbons, sulfur dioxide, smoke, dust, etc., and then adhere to the surface of the zinc coating to form Electrolytes. The electrolyte electrochemically corrodes the zinc layer with poor chemical stability, resulting in a powdery corrosion product - white rust.
The main reasons for corrosion of the zinc layer indoors are: ① High indoor air humidity; ② The finished product is stored in the warehouse without drying; ③ There is a layer of water film condensation on the surface of the zinc layer. When the water content in the air reaches 60% or is in the range of 85~95%, and the PH value is less than 6, the corrosion reaction will be more intense.
When the water temperature reaches about 70°C, the corrosion rate of the zinc layer is faster. Methods to prevent white rust include: ① When stacking zinc plates, there must be no condensation on the surface; ② Air circulation should be maintained in the warehouse, and the relative humidity of the air should not be 60% or Between 85~95%; ③ There should be no harmful gases and excessive dust when stacking zinc plates; ④ The surface of the galvanized layer should be oiled and passivated.
