Here is a summary of the cold rolling line key equipment and processes involved.
| Equipment/Process | Key Features | Function in High-Ductility Production |
|---|---|---|
| Complete Rebar Production Line | Integrated line with descaling, rolling, heat treatment, shearing, and collecting. | Produces ribbed steel bar with high elongation, combining cold rolling and in-line heat treatment. |
| Multi-Roller Cold Rolling Mills (e.g., 6-high, 12-high) | Small diameter work rolls, high roll stiffness, excellent shape and thickness control. | Rolls high-resistance metals into thin strips with uniform microstructure and mechanical properties. |
| In-line Heat Treatment | Intermediate Frequency (IF) heating system with multiple heat sources. | Crucial for achieving high ductility by controlling the microstructure (e.g., annealing, tempering). |
| Advanced Control Systems | Automatic Gauge Control (AGC), shape control, and PLC systems. | Ensures consistent and precise product dimensions (thickness, flatness), which influences mechanical properties. |
High-Ductility Cold Rolling Line Equipment
🔬 How to Achieve High Ductility
The "high-ductility" of the product is not solely determined by the rolling mill itself, but by a combination of processes.
The Critical Role of Heat Treatment: For many materials, cold rolling alone increases strength but reduces ductility. Integrating a heat treatment process immediately after rolling is essential for restoring ductility. The inline IF heat treatment in the rebar line is a perfect example of this principle in action.
Grain Boundary Engineering: Modern metallurgical research shows that ductility can be significantly enhanced by controlling the material's microstructure. Techniques like "grain boundary engineering" through specific strains and annealing processes can create a high fraction of "special boundaries," which help in achieving both high strength and excellent ductility.
Controlling the Cooling Process: For some steel grades, controlling the cooling path after hot rolling or heat treatment can produce a beneficial dual-phase microstructure (e.g., Ferrite + Bainite). This structure is known to break the traditional strength-ductility trade-off, providing a superior combination of both properties.
