Common surface defects?
Horizontal crease: Caused by bending deformation due to the yield plateau during uncoiling; common in thicknesses of 3–6 mm.
Oxide scale: Incomplete removal after hot rolling, affecting coating.
Rust: Caused by moisture during storage; requires rust-preventive oil/packaging.
Edge cracks: Poor edge structure; prone to cracking when bending.
Deoxidation method: Boiling/Killed/Special killed?
Boiling steel (F): Incomplete deoxidation, low cost, high impurities (A/B grade).
Killed steel (Z): Complete deoxidation, good quality (B/C grade).
Special killed steel (TZ): More thorough deoxidation, superior low-temperature toughness (D grade).
Steel coil weight and diameter?
Standard: 20–30 tons/coil; Coil diameter: Φ508–Φ610 mm; Width: 1000–1500 mm.
Surface treatment methods?
Rust-preventive oil, galvanizing, aluminum zinc plating, painting, sandblasting, pickling and passivation.
Welding performance?
Excellent, low carbon, low carbon equivalent; suitable for arc welding, gas welding, and spot welding; no preheating required (for thick plates > 20mm, preheating to 100–150℃ is required).