Cast iron rolls are the main consumable of rolling mills and have a great influence on product quality, processing technology and equipment selection. After years of extensive use in the iron and steel industry, cast iron rolls have made great progress in manufacturing process and materials. The high quality cast iron roll can guarantee the accuracy, surface quality and service life of the final product.
The use of cast iron rolls in the iron and steel industry is mainly due to its very high hardness and abrasion resistance, which are very important mechanical properties for rolling mill rolls. However, due to its low thermal conductivity, high thermal expansion coefficient and large thermal deformation, its high temperature mechanical performance is poor. In addition, cast iron is brittle at low temperature, and its low impact toughness makes it difficult to improve its life.
As early as the 18th century, German engineers began to study the new material of nodular cast iron of spheroid type. The nodular cast iron is composed of graphite in the spheroidal form, which makes the matrix of cast iron become more stable, increases its impact toughness and increases its anti-fatigue performance. As a result, cast iron roll using spheroidal graphite cast iron as material has a higher comprehensive performance when compared with normal cast iron roll.
In recent years, with the development of milling technology, the quality of steel rolling is improving all the time. The application of fine grains and high strength steel has been widened, thus requiring high and new technology. This mainly lies in the casting process of cast iron rolls, in which the core technology is to select the type, number and type of additives to prevent carburization and graphitization. The most widely used alloy elements for nodular cast iron rolls are Cu and Ni, which can improve the graphitization resistance of cast iron.
In the selection of cast iron rolls, the size, weight and materials of the rolls are all considered. Generally speaking, the diameters range from 200-1200mm, and the length is slightly shorter than the roller surface. The weight of large diameter cast iron rolls can reach 130 tons, and special design is needed for the roll support device. According to different service conditions and product requirements, cast iron roll material is usually grade 10-30 or grade 30-100. As one of its main consumables, cast iron rolls play a major role in iron and steel production. With its improvements in process, material and craftsmanship, its performance has been improved. This will ensure higher product quality and quality stability.
