High-carbon high-speed steel roll (referred to as high-speed steel roll) is the hot roll material with the shortest time, the fastest development, and the widest application prospect. High-speed steel is also known as wind steel or front steel, which means that it can harden even when cooled in the air when quenched, and it is very sharp. It is a complex alloy steel containing carbide-forming elements such as tungsten, molybdenum, chromium, and vanadium. The total amount of alloying elements is about 10% to 25%.
High Speed Steel Roll Application
The application of high-speed steel rolls is an important part of the development of modern steel rolling production. It is another major change to the development of the iron and steel industry after microalloying, controlled rolling, and controlled cooling technology. High-speed steel rolls have been widely used in steel rolling production in the fields of plate, section steel, bar, and wire in Japan, not only for work rolls but also for backup rolls. The good wear resistance of high-speed steel rolls is inseparable from its characteristics which are significantly different from traditional rolls.
Performance Of High Speed Steel Rolls:
(1) High-speed steel rolls have high carbon content and high alloying elements such as vanadium, chromium, tungsten, molybdenum, and niobium. Therefore, the types of carbides in the roll structure are mainly MC type and M2C type. High hardness and good wear resistance.
(2) The high-speed steel roll has good thermal stability, and at the rolling temperature, the roll surface has high hardness and good wear resistance.
(3) The high-speed steel roll has good hardenability, and the hardness from the surface of the roll body to the inside of the working layer hardly decreases, so as to ensure that the roll has the same good wear resistance from the outside to the inside.
(4) During the use of the roll, under good cooling conditions, a thin and dense oxide film is formed on the surface of the roll body. This uniform, thin and dense oxide film exists for a long time without falling off, which makes the high-speed steel roll wear-resistant. significantly improved.
(5) The formation of an oxide film on the roll surface of the high-speed steel roll during rolling reduces the friction between the rolled material and the roll surface, so it is easy to cause slippage during the rolling process, which increases the difficulty of rolling mill adjustment.
(6) The high-speed steel material has a large expansion coefficient and good thermal conductivity, which is easy to cause roll shape changes during rolling and affects the rolling accuracy. Therefore, when the high-speed steel roll is used in the plate and strip mill, not only the design of the cooling system but also the design of the roll shape must be changed.
(7) Since the core of the high-speed steel roll is made of alloy ductile iron, graphite steel, or forged steel, the strength of the roll neck of the roll is high.
(8) Due to the high wear resistance and poor accident resistance of high-speed steel materials, the use effect of high-speed steel rolls not only depends on the quality of the high-speed steel rolls themselves but also depends on the conditions of use of the rolls and the maintenance of the rolls.