The 20th century is the era of great development of the world steel industry. World steel production in 1900 was 28.5 million tons, reaching 843 million tons in 2000, an increase of 28.5 times. From the 1950s to the 1970s, steel production increased from 200 million tons to 700 million tons, which was the first period of rapid growth. Later, due to the economic crisis, the economic depression was between 700 million and 800 million t/a, and it was not more than 800 million tons until 2000. In the 21st century, world steel production entered a second period of rapid growth, from 800 million t/a to 1.14 billion tons in 2010. It is still in this period of rapid growth. Affected by the financial crisis, the world's crude steel output in 2009 was 1.22 billion tons, down 8%. In 2010, global crude steel production reached 1.414 billion tons, a year-on-year increase of 15%, a record high. In 2010, China's crude steel and steel output were 6.2665 billion tons and 792.27 million tons, up 9.3% and 14.7% respectively. After 2011, steel production will remain at around 1.6 billion tons.

The basic characteristics of high-speed steel rolls are: high hardness of carbide; good thermal stability; excellent toughness; good hardenability; strong ability to form oxide film; good resistance to thermal cracking; good wear resistance. The main features of the high-speed steel roll components are: high carbon content and vanadium content, in order to obtain more high-hardness MC-type carbides and improve the wear resistance of the rolls. The high chromium content makes the roll contain a certain amount of M7C3 type carbide, which is beneficial to improve the surface roughness of the roll and reduce the rolling force. In addition, the centrifugal casting high-speed steel roll contains 5% or less of niobium, which is advantageous for reducing segregation caused by large difference in alloying elements and carbide density in high-speed steel.

High-speed steel roll manufacturing techniques include the following: forging high speed steel rolls, casting high speed steel rolls, spray deposition forming (OSPREY) high speed steel rolls and hot isostatic pressing (HIP) to produce high speed steel rolls. Among them, the methods for casting high-speed steel rolls are: centrifugal casting (CF), continuous casting outer layer forming (CPC), electroslag remelting (ESR) and liquid metal electroslag welding (ESLLM).

The main contents of the research progress of high-speed steel roll heat treatment include the following aspects: the influence of quenching on the microstructure and properties of high-speed steel rolls In order to accurately formulate the heat treatment process of high-speed steel rolls. According to the continuous cooling curve analysis after austenitizing at 1050 °C, the bainite temperature of the high speed steel roll is lower than 400 ° C, and the cooling rate of obtaining bainite is lower than 10 ° C / s, when the high speed steel roll is cooled. At a rate exceeding 10 ° C / s, a hardened martensitic matrix of high hardness is obtained. The austenitizing holding time has a certain influence on the microstructure and properties of the high speed steel roll. The quenching holding time affects the microstructure of high speed steel rolls. Baosteel will have a content of 2.28% C, 4.66% W, 4.79% Mo, 6.05% V, 7.70% Cr, 0.60% Ni, 0.80% Si and 0.50% Mn high speed steel rolls. After austenitizing at 1000 ° C, the microstructure changes were studied. After austenitizing for 2h, the carbides in the high-speed steel roll structure were mainly M7C3 type; after 4h heat preservation, the carbides were mainly M2C type; after 6h heat preservation, the carbides were mainly MC type. The austenitizing holding time also affects the wear resistance of high-speed steel rolls. The austenitizing heat preservation is 2h. The high-speed steel has the worst wear resistance and the carbide peeling is serious. The holding time is extended to 4h. The high-speed steel rolls wear evenly, only a few. The coarser M2C type carbides were peeled off; the holding time was extended to 6 hours, the M7C3 type carbides disappeared, the high hardness MC carbides increased, and no carbide falling off occurred. The high speed steel rolls had the best wear resistance.

The effect of tempering on the microstructure and properties of high speed steel rolls. Reasonable control of tempering temperature In the actual use of high-speed steel rolls, it is not the best to use the highest tempering hardness. The effect of tempering temperature on hardness, wear resistance and surface roughness of rolls containing 2.0% C, 5.0% V, 3.0% Mo, 1.5% W, 6.5% Cr and 1.0% Ni high speed steel. After tempering at 540 ° C, the hardness reached the highest value, and the hardness gradually decreased after exceeding 540 ° C. In addition, at 540 °C tempering, the high-speed steel roll mill has the least weight loss and the best wear resistance. As the tempering temperature increases, the wear loss weight increases and the wear resistance decreases.