The main working components and tools on the mill that produce continuous plastic deformation of the metal. The roll is mainly composed of a roll body, a roll neck and a shaft head. The roll body is the middle part of the roll that actually participates in the rolling of the metal. It has a smooth cylindrical or grooved surface. The roll neck is mounted in the bearing and transmits the rolling force to the frame through the bearing housing and the pressing device. The transmission end shaft head is connected to the gear base through the connecting shaft, and transmits the rotational torque of the motor to the roller. The rolls can be arranged in the form of two rolls, three rolls, four rolls or multiple rolls in the rolling mill stand.
The variety and manufacturing process of rolls are constantly evolving with the advancement of metallurgical technology and the evolution of rolling equipment. Gray cast iron rolls with low strength are used in the medieval rolling of soft non-ferrous metals. In the mid-18th century, the United Kingdom mastered the production technology of chilled cast iron rolls for rolled steel sheets. The advancement of European steelmaking technology in the second half of the 19th century required the rolling of larger tonnage ingots, whether the strength of grey cast iron or chilled cast iron rolls could not meet the requirements. Ordinary cast steel rolls with a carbon content of 0.4% to 0.6% were born. The emergence of heavy-duty forging equipment has further enhanced the toughness of the forged rolls of this composition. The use of alloying elements and the introduction of heat treatment in the early 20th century significantly improved the wear resistance and toughness of hot and cold rolled rolls of cast steel and forged steel. The addition of molybdenum to the cast iron rolls for hot rolled strips improves the surface quality of the rolled material. The flushing compound casting significantly increases the core strength of the casting rolls.