What are the functions and elongation rates of surface finishing (smoothing)?
A: Improves sheet shape, eliminates yield plateaus, and enhances surface quality; elongation 0.5-2.0% (0.5-1.0% in soft state).
What are the thickness tolerance standards?
A: Ordinary precision ±0.02mm, high precision ±0.01mm; width tolerance ±0.5mm, flatness ≤3mm/m.
What are the common surface defects of 1010 cold-rolled steel?
A: Scratches, pitting, oxide scale, peeling, indentations, edge waviness, camber, tapering, and oil residue.
How to prevent surface scratches?
A: Use mirror-finish rolls, stabilize tension, control emulsion cleanliness, electrolytic cleaning (oil ≤5mg/m²), and avoid foreign matter indentation.
What are the causes and prevention of oxide scale formation?
A: Improper annealing atmosphere, prolonged uncoiling exposure time; control the nitrogen-hydrogen protective atmosphere, shorten exposure time, and apply anti-rust oil.