1.Why is galvanized coil an ideal material for traffic sign poles?
Excellent Corrosion Resistance - Core Advantage
Sacrificial Anodic Protection: Zinc is more chemically active than iron. When the galvanized surface is scratched or slightly damaged, the zinc acts as a "sacrificial anode" and corrodes preferentially, protecting the underlying steel substrate from rust. This is a highly effective electrochemical protection.
Barrier Protection: The complete galvanized layer completely isolates the steel substrate from the external environment, forming a physical barrier.
Long Life
A high-quality hot-dip galvanizing treatment can ensure a maintenance-free service life of 30-50 years for traffic poles in typical atmospheric conditions. This significantly reduces lifecycle costs.
Proven Process and Standards
The transportation infrastructure industry has very strict specifications and standards (for example, China's GB/T 13912 "Metallic Coatings - Hot-Dip Galvanized Coatings on Steel Parts - Technical Requirements and Test Methods").
Specific requirements for the thickness, adhesion, and uniformity of the galvanized layer ensure reliable quality.
2.What is the standard process for traffic poles?
Guaranteed Integrity: Hot-dip galvanizing the entire, pre-formed rod ensures a uniform, thick coating of zinc on all internal and external surfaces, including welds, corners, and interior surfaces. This is crucial for corrosion protection of hollow rod interiors, as direct galvanizing with coils offers no protection.
Stronger Protection: Hot-dip galvanizing typically produces a thicker zinc layer than continuous galvanized coils (e.g., GI, Galvanized Steel Coil), resulting in a longer corrosion life.
3.What is the standard process?
Steel plate/strip → Made into rod → Hot-dip galvanizing
4.What is the non-standard/low-cost process?
Galvanized coil → Directly rolled into rods
5.What are the mainstream applications?
Galvanizing is a standard and mandatory anti-corrosion process for outdoor steel structures such as traffic sign poles, street light poles, and signal light poles.