Flat steel can be finished steel, can also be welded pipe stock and laminated rolled sheet bar.
Main application: flat steel can be used for making hoop iron, tools and mechanical parts, and used for building structure parts and escalators.
The hot-dipped galvanizing process creates a multi-layer protective coating (zinc-iron alloy layer + pure zinc layer) that acts as a physical barrier and provides "sacrificial anode protection," delivering long-lasting rust resistance:
Dense Multi-Layer Coating: The inner zinc-iron alloy layer (5–15 μm thick) bonds tightly to the base steel, while the outer pure zinc layer (40–80 μm thick) forms a smooth, impermeable shield. This structure effectively blocks moisture, oxygen, road salt, industrial fumes, and even mild chemicals from reaching the steel substrate.
Sacrificial Protection: If the coating is scratched or damaged (e.g., by impact or wear), the surrounding zinc will corrode preferentially (instead of the steel) to "protect" the exposed steel—unlike paint or electroplating, which lose protection once damaged.
Long Service Life: In typical environments (e.g., urban, rural, or non-coastal areas), it can resist rust for 20–50 years without additional anti-corrosion treatments. Even in harsh conditions (e.g., coastal salt-spray areas or humid industrial zones), its service life is 10–25 years, far exceeding uncoated or painted steel bars.
II. High Structural Strength & Load-Bearing Capacity
The base steel (usually low-carbon steel like Q235 or Q355) retains its inherent mechanical properties after galvanizing, ensuring the flat bar meets structural and load-bearing demands:
Excellent Tensile & Yield Strength: The base steel provides high tensile strength (Q235: ≥375 MPa; Q355: ≥470 MPa) and yield strength (Q235: ≥235 MPa; Q355: ≥355 MPa), making the flat bar suitable for load-bearing scenarios—such as supporting brackets, structural framing, or reinforcement bars in construction.
Rigidity for Flat Profiles: The flat, rectangular cross-section (common thickness: 3–20 mm; width: 10–150 mm) offers stable contact with surfaces, ensuring good rigidity when used as floor joists, electrical grounding bars, or hardware brackets (e.g., for securing pipes or cables).
No Strength Loss from Galvanizing: The hot-dip process does not weaken the base steel’s mechanical properties (unlike some high-temperature heat treatments). The zinc coating only adds protection without compromising structural integrity.
III. Cost-Effective & Low Maintenance
Compared to other anti-corrosion steel products (e.g., stainless steel or painted steel), hot-dipped galvanized flat steel bar balances performance and cost, with long-term economic benefits:
Low Initial & Lifecycle Costs: While its upfront cost is slightly higher than uncoated or painted steel, the zero or minimal maintenance requirement (no repainting, rust removal, or re-coating) drastically reduces long-term expenses. For example, a galvanized flat bar used in outdoor fencing avoids annual painting costs, offsetting the initial investment within 3–5 years.
Easy Cleaning: The smooth zinc coating resists dirt, dust, and grime accumulation. Routine maintenance only requires wiping with a damp cloth or rinsing with water—no need for harsh chemicals or specialized cleaning tools.
