The three main rolling process schedules refer to the deformation system, rolling speed system, and rolling temperature system.
1. Deformation System
Under specific rolling conditions, the process in which raw materials are deformed into final products is known as the deformation system. Its core purpose is to define both the total reduction and pass reduction. The distribution of reduction is a key parameter and serves as an important basis for equipment selection and roll pass design. The deformation system plays a critical role in determining mill capacity and product quality. Processes such as the reduction schedule of the roughing mill, the pass design of section mills, the reduction schedule in plate rolling, and part of the tube rolling procedure all fall under the deformation system. Pass design includes determining the number and sequence of rolling passes, distributing elongation ratios, designing sectional passes, and designing roll passes.
2. Rolling Speed System
The rolling speed system focuses on defining the rolling speed, which involves determining the speed of each rolling pass at different stages of the process. Higher rolling speeds typically result in greater mill productivity, making speed a primary factor in increasing output. However, the rolling speed is constrained by factors such as the structural strength of the mill, motor capacity, and the level of automation. The speed system includes the speed schedule for roughing mills and the speed settings for each stand in a continuous rolling mill.
Speed control also varies by mill type. In continuous mills, for example, it is essential to maintain a consistent metal flow rate (metal seconds) through each stand by adjusting the individual rolling speeds accordingly.
3. Rolling Temperature System
The temperature system governs the temperature range during rolling, particularly the initial (opening) rolling temperature and the final rolling temperature. This schedule directly affects mill productivity, equipment safety, and product quality.
These three systems—deformation, speed, and temperature—are closely interrelated and mutually restrictive. A well-balanced design must account for the interactions among them to achieve optimal rolling performance.
