An "Interpass Annealing Furnace" is a specialized equipment used in the heat treatment process of metal during a multi-pass rolling operation, typically in the production of steel or certain non-ferrous metals. The purpose of interpass annealing is to optimize the material's microstructure and properties between rolling passes, ensuring better formability and reducing the risk of defects.
Usage of Interpass Annealing Furnace:
- Heat Treatment during Multi-Pass Rolling: The interpass annealing furnace is used to subject the metal to a controlled heating and cooling process between consecutive rolling passes.
- Microstructure Optimization: Interpass annealing is done to refine the material's microstructure and relieve stresses accumulated during the rolling process.
How it Works:
- Multi-Pass Rolling: The metal is subjected to a series of rolling passes in a rolling mill to achieve the desired thickness reduction.
- Transfer to Annealing Furnace: After each rolling pass, the metal is transferred to the interpass annealing furnace before the next rolling pass.
- Heating: In the annealing furnace, the metal is heated to a specific temperature below the recrystallization temperature (the temperature at which new grains form during rolling).
- Soaking: The metal is held at the annealing temperature for a predetermined period, allowing for the relaxation of internal stresses and the diffusion of certain elements.
- Controlled Cooling: After soaking, the metal is cooled slowly and uniformly to room temperature to avoid the formation of new stresses.
- Interpass Time: The time spent in the annealing furnace is called the "interpass time," and it can vary depending on the material and rolling process.
- Next Rolling Pass: After the interpass annealing process is completed, the metal is sent for the next rolling pass, and the cycle repeats until the desired thickness is achieved.