What are the advantages of SPCC coils compared to hot-rolled coils?
A: Room temperature rolling results in no iron oxide scale, better surface quality, a smoother appearance, higher dimensional accuracy, and the ability to be rolled into thinner sheets, offering superior forming and processing performance.
What causes SPCC coils to crack easily during processing?
A: This could be due to excessively high hardness in the fully hard state, an unreasonable cold rolling reduction rate, or a high inclusion content in the raw materials, leading to poor forming performance and easy cracking during processing.
How to improve the forming performance of SPCC coils and avoid cracking during processing?
A: Optimize its chemical composition, adjust the hot rolling coiling temperature and cold rolling reduction rate, and control the surface hardness of the fully hard state product below 95HRB to improve forming performance.
What causes black spots and black bands to appear on SPCC coils after annealing?
A: This is often related to the annealing process. For example, excessively rapid heating can lead to a large temperature difference between the inside and outside of the coil core, insufficient grain growth, or improper atmosphere control during annealing, resulting in these surface defects.
How to solve the bonding defects after SPCC coil annealing?
Answer: Slow down the heating rate during the high-temperature stage. After 620℃, heat at a rate of 25℃/h and extend the holding time by 1 hour. Simultaneously, adjust the holding time according to the furnace load; extend the holding time appropriately when the furnace load increases.