How to improve the roll performance to meet the needs of rolling mill is a new topic.

Roller is one of the main spare parts consumed in steel rolling production, and the consumption cost of roller accounts for about 5%- 15% of the production cost of steel rolling. If the factors such as shutdown, production reduction and equipment maintenance increase caused by roller consumption are taken into account, the proportion in production cost will be higher. Roller quality not only relates to the production cost of steel rolling and the productivity of rolling mill, but also affects the quality of rolled products to a great extent. With the development of steel rolling technology, the speed and automation of rolling mills are constantly improved, which puts forward higher requirements for the quality of rolls, especially the wear resistance, strength and toughness of rolls. In recent years, due to the special demand for steel, higher requirements are put forward for the size, surface accuracy and performance of steel. In addition, with the development of rolling technology, the working environment of rollers is getting worse and worse. Taking hot continuous rolling as an example, the roller has been in the harsh working conditions of high temperature, high load and high speed for a long time, which requires higher performance of the roller. How to improve the performance of rolls to meet the needs of rolling mills is a new topic faced by roll developers.

Since 1996, the annual steel output has exceeded 1 100 million tons, and the steel output has been increasing continuously. 200 1, an increase of 65438+509 million t, an increase of 49.6438+0% compared with 1996. According to the statistics of the World Iron and Steel Association (IISI), the crude steel output in China in 2006 was 4188,000 tons, with an increase of 3 13.8% in 10 years. The proportion of China's crude steel production in the world has also increased exponentially. 1996, China became the country with the largest steel output in the world for the first time, but the total output only accounted for13.5% of the world total output; In 2006, its share rose to 33.8%, slightly higher than one-third of the total production of vinegar cans in the world. At present, the roller consumption per ton of steel in China exceeds 2.0 kg/t, hundreds of thousands of tons of rollers are consumed every year, and the roller capital is more than 7 billion yuan every year, while the roller consumption per ton of steel in developed countries is only 1.0- 1.4kg/t in the same period. In order to meet the actual needs of steel rolling production, China needs to spend a lot of foreign exchange to import rollers every year. If the roller consumption in China can be reduced by 30%-40%, it will not only save a lot of foreign exchange, but also save a lot of roller materials. Therefore, it is of great significance to develop new roll materials and their manufacturing methods for improving roll quality, prolonging roll life, improving rolling mill operation rate and reducing rolling cost.

Replacing roll material is an important measure to improve roll performance. The obvious trend of roll material development is to widely use alloying elements and gradually improve the alloying degree. For example, the pre-finishing stage of hot rolled strip developed from high nickel-chromium infinite chilled cast iron roll in 1930s to semi-steel roll in 1960s, high chromium cast iron roll and high chromium cast steel roll were used in 1970s, and high speed steel roll was used in the late 1980s. The material of cold rolled strip work roll has developed from 2.0% Cr steel to 3.0% Cr and 5.0%Cr steel. Semi-high speed steel was used in the 1990s, and recently it was also used. The roll material of bar, wire and profile rolling mill has also developed from ordinary chilled cast iron, alloy ductile cast iron, high nickel-chromium infinite chilled cast iron, high chromium cast iron and forged alloy tool steel to cemented carbide. At present, the application of high-speed steel roller in high-speed wire rod mill and bar mill has also achieved satisfactory results.