Galvanized steel strip used for cable armor is a metal material specially used to provide mechanical protection for cables and optical cables. It is galvanized to enhance its corrosion resistance and is suitable for harsh environments such as outdoor, underground, and humid environments.
What are the characteristics of Galvanized Steel Strip For Cable Armoring?
Base material: cold-rolled low-carbon steel strip (such as Q195, Q235, SPCC, etc.), low carbon content (≤0.15%), good plasticity, easy to process and shape.
Galvanized layer:
Hot-dip galvanizing (HDG): The zinc layer is thicker (usually 20~60μm), with strong corrosion resistance and suitable for harsh environments.
Electrogalvanizing (EG): The zinc layer is thinner (5~20μm), the surface is more uniform, and the cost is lower.
Mechanical properties:
Tensile strength: ≥300 MPa (as required by GB/T 2952 standard).
Elongation: ≥20%, to ensure no cracking during wrapping.
Surface treatment: Anti-rust oil or passivation can be applied to further prevent rust.
Armor forming process
Unwinding
The galvanized steel strip is loaded into the armoring unit, and the tension is controlled to prevent deformation.
Forming rolling
The steel strip is pressed into a corrugated shape (common) or a flat strip through multiple sets of rollers to enhance flexibility and pressure resistance.
Corrugation parameters: peak height 1~3mm, wave distance 10~30mm (adjusted according to cable diameter).
Welding (in continuous production)
The head and tail of the steel strip are laser welded or high-frequency welded to ensure continuity.
Rewinding
After forming, the steel strip is wound into a disk and packaged (moisture-proof paper + steel-wood pallet).
Common Problems and Solutions of Galvanized Cold Rolled Steel Strip for Armoring
Zinc layer peeling off:
Reason: Residual impurities on the surface of the substrate or improper galvanizing process parameters.
Solution: Strengthen pickling and surface activation treatment.
Forming cracking:
Reason: Insufficient elongation of the steel strip or excessive roller pressure.
Solution: Optimize annealing process or adjust roller gap.
Insufficient salt spray resistance:
Reason: The zinc layer is too thin or the passivation is poor.
Solution: Increase the thickness of the zinc layer or use chromium-free passivation technology.
Can galvanized steel armored cables be used underwater?
Yes, but they must be used with a waterproof sheath (such as PE or lead sheath), and the zinc layer must be thickened (≥80g/m²) to resist long-term immersion corrosion.
