1010 What is the raw material for cold rolling?
A: Hot-rolled coil (usually SPHC/DC01), thickness 2.0-4.0mm, surface free of severe oxide scale and inclusions.
What is the appropriate total reduction rate for cold rolling?
A: 50-60% total reduction rate for soft finished products (≤60% is less prone to cracking); 70-75% for fully hardened products.
How should the rolling tension be set?
A: Low tension 5-8MPa, to prevent strip waviness and edge cracking; tension decreases by 10-15% for each stand in continuous rolling.
What are the emulsion concentration and temperature?
A: Concentration 2-4%, temperature 40-50℃; to ensure lubrication and cooling, reduce surface roughness, and reduce roll wear.
What are the annealing process parameters?
A: 700-750℃, holding for 2-4 hours, nitrogen-hydrogen mixed atmosphere (9:1), slow cooling in the furnace; to eliminate work hardening and improve plasticity.