Zn Electro-Galvanized Steel Sheets

• Workability

  Since electrical galvanized steel has a lower coating weight and has no heat-affected zones during the manufacturing process compared to GI and GA, it has the material characteristics and workability comparable to those of the base metals, that is, cold rolled (CR) or hot rolled (HR) sheets.

• Corrosion Resistance

  Substrate steel can be protected by the sacrificial anode reactions caused by the galvanic actions of Zinc and, even if it is exposed to air, can still be protected from corrosion by a thin film formed on the surface. (Some post-coated steel sheets are used for automobiles for better anti-corrosion property.)

• Paintability

  The steel’s flat and even surface provide good conditions for painting. Phosphate treatment improves its paint adhesion and anti-corrosion properties after painting.

• Weldability

  Pure Zn galvanized steel has lower weldability than cold rolled steel due to a wide area of contact under pressure and inferior electrical conductivity. However, it allows for spot or seam welding if its surface condition permits and post-treatment is applied.

• Welding Current

  

• Properties During Repeated Welding

  

Comparison of Anti-Corrosion Levels Between Non-Treated and Phosphate-Treated Zn-Galvanized Steels

• White Rust Testing

  

• Red Rust Testing

  

Zn-Ni Alloy Coated Steel

This product has been developed in order to improve the anti-corrosion durability (and prevent the through-hole corrosion) against deicers (e.g., NaCl, CaCl2) for melting ice from the roads in winter. In addition, since the coated layer of the product is solid and has a higher melting point than those of other plated layers by adding some Ni, the layer does not easily soften or melt as a Pure Zn coated layer does. The steel also allows for welding at a lower current than pure Zn galvanized steel and has a superior corrosion resistance over a long period of time.

• Comparison of Corrosion Resistance Between Pure Zn and Zn-Ni

  

• Comparison of Weldability Between Pure Zn and Zn-Ni

  

Types of Surface-Treated Products

• Structure of Coated Film

  Cr6+, Cr3+/CrO3, resins and others were coated in order to improve the anti-corrosion and paint adhesion properties after Zn & alloy plating.

  

• After Improvement

  Some other chemicals having properties similar to chrome are applied.An example can be an organic-inorganic polymeric composite (containing some additives).
   

  

Post-Treatment Code

Quality Features by Product