The manufacture of high-speed steel rolls was earlier developed by the Japanese in 1988 and used in the hot strip mill. The United States began to introduce high-speed steel rolls in the early 1990s, and Europe started relatively late. High-speed steel rolls are generally defined as tool steels that have the ability to maintain hardness during high-speed cutting.
The material of the working layer of the roll has high red hardness and high wear resistance during hot rolling. The content of carbon elements and other carbide-forming alloy elements in high-speed steel rolls is generally greater than 15%, while in tool steel rolls Less than 15%. The difference between high-speed steel rolls and semi-high-speed steel rolls is mainly reflected in the difference in alloy content. The content of carbon elements and other carbide-forming alloy elements between the two is nearly doubled. The casting HSS rolls used in large quantities are mainly produced by three methods:
One is the vertical centrifugal casting method, which is used in Europe and North America to produce H SS rolls.
The second is CPC-continuous casting method. 60% to 70% of H SS rolls in Japan are produced by CPC method, and 30% to 40% of H SS rolls are produced by centrifugal casting method. At present, only Nippon Steel Corporation in the world has successfully mastered the manufacturing technology for the production of H SS rolls by the CPC method.
The third is ESR-electroslag casting method, which is a method of producing H SS rolls based on CPC method and electroslag purification. Ukraine and Belgium have produced a small number of rolls by this method.