High-speed steel rolls are high-carbon, high-speed steel composite rolls and have become an important part of the development of modern steel rolling production. After 20 years of development, they have been widely used in rolling mills around the world. Currently, cast high-speed steel rolls are not only widely used in the finishing stands of cold and hot strip rolling mills, but also in the finishing stands of wire and bar rolling mills. This is a very good application, so let's learn about the advantages of high-speed steel rolls below.

　　Advantages of high-speed steel rolls:

　　1. High hardness of carbides: In the past, the rolls used were mostly distributed with Fe3C or M7C3 eutectic carbides on the matrix, with a coarse structure and low hardness. High-speed steel rolls generally use high-C, high-V high-speed steel, and also contain a larger amount of alloying elements such as Cr, Mo, W, Nb, and Co. During solidification and heat treatment, these alloying elements form primary and secondary carbides. Things. The carbides in high-chromium cast iron rolls are M7C3 (2500Hv) and M23C6 (1600Hv). In infinite cold-hard cast iron rolls, the carbide is Fe3C (1300Hv).

　　2. Good thermal stability: High-speed steel rolls contain a larger amount of W, Cr, Mo, V, and Nb elements, and have good thermal stability. Studies have found that the hardness of ordinary roll materials decreases significantly with increasing temperature, while high-speed steel rolls still maintain 500Hv at 600, which will greatly improve the wear resistance of the rolls. This trend is even more obvious, especially after adding Co elements distributed in the matrix.

　　3. It is easy to form an oxide film during use. In the rolling process, if a continuous, dense, uniform, and well-bonded oxide film is formed on the surface of the roll, it can not only reduce the friction coefficient between the roll and the rolled material, but also improve the dimensional accuracy and surface quality of the rolled material. In the initial stage of use, ordinary rolls have greater wear due to the lack of oxide film protection. High-speed steel rolls will quickly form an oxide film during use. The appearance of the oxide film can reduce the friction between the strip and the roll surface, prevent the roll from sticking to the steel, and improve the service life of the roll. Compared with ordinary rolls, high-speed steel rolls have lower initial wear, which is conducive to improving the wear resistance of high-speed steel rolls.

　　4. Good hardenability: High-speed steel rolls have good hardenability. At room temperature, within 50mm of the working layer, the hardness drop from the roll surface to the core is less than 3HS, which can ensure that the roll has good wear resistance from the outside to the inside.

　　5. Good toughness: Compared with general infinite cold-hard cast iron, high-chromium cast iron, and semi-steel rolls, high-speed steel rolls have high basic mechanical properties, tensile strength, and fracture toughness. Rolls entering the field.

　　6. Good resistance to thermal cracking: Due to its unique structural characteristics, high-speed steel can effectively inhibit the formation and expansion of cracks. In actual use, it has been found that the resistance to thermal cracking of high-speed steel rolls is indeed superior to that of high-chromium cast iron rolls. Therefore, if a general production accident occurs, the impact of the accident can be eliminated by normal grinding or a small amount of additional grinding, simplifying the processing technology and saving costs.

　　7. Good wear resistance: Compared with semi-steel, high-chromium cast iron, and high-nickel chromium infinite cold-hard cast iron rolls, the rolling tonnage of high-speed steel rolls has been greatly improved. The F1-F4 stands are about 10000t, and the F5 stand is about 6000t, which shows that high-speed steel rolls have good wear resistance. The increase in the rolling tonnage of high-speed steel rolls leads to a significant decrease in roll consumption. Under the same rolling conditions, the roll consumption of high-speed steel rolls is 1/5 of that of high-chromium cast iron rolls in the F1 stand, and high-chromium cast iron rolls in the F2 stand. The F4 stand is 1/13 of the high-nickel chromium infinite cold-hard cast iron roll, and the F5 stand is 1/8 of the high-nickel chromium infinite cold-hard cast iron roll.

　　The above is an introduction to the advantages of high-speed steel rolls. For more information, please contact us!