Some knowledge points of rolls
The cable tray equipment roll is an important part of the cable tray equipment. What are the characteristics of the design and use of cable tray equipment rolls? The design and use of cable tray equipment rolls have the following characteristics.
The principle of average force in each pass makes the average force of the entire line of rolls balanced and prolongs the service life of the rolls. The arc of the track is the core part of the slide rail. The arc after the last press-in should be effectively protected by the upper and lower rollers or the horizontal wheel during the next rolling and edging.
The arc position of the cable bridge equipment material will definitely change during the stretching process, the R will become a triangle, the steel ball will not reach the bottom, and the two-point contact will generate noise. When R becomes larger, the matching rail will shake, the track of the rail will be blurred, the force will be uneven, the rail will be deformed, and the service life will be shortened. The machining accuracy of the rollers is the key. Therefore, a special tool is specially made under the projection equipment, which will be magnified 20 times for testing.
The carbon content of cast iron rolls is about 2.5%-3.5%. According to the main materials, it can be divided into four categories: ordinary cast iron rolls, high nickel-chromium infinite chilled composite cast iron rolls, high chromium composite cast iron rolls and alloy ductile iron rolls. The common structure of cast iron rolls can be divided into three categories: matrix, cementite and graphite. The matrix structure is mainly bainite, ferrite, pearlite, bainite and martensite. Graphite in cast iron generally comes in two forms: flakes and spheres.
Ordinary cast iron rolls can be divided into chilled cast iron rolls, medium and low alloy infinite chilled cast iron rolls and medium and low alloy ductile iron rolls. Chilled cast iron is a kind of cast iron obtained by using the supercooling of molten iron and the chilling of the surface of the mold. The surface of the roll body is chilled to form a white layer with high hardness and good wear resistance. Chilled cast iron rolls can be divided into non-ductile iron, ductile iron composite and spherical core according to the manufacturing process and core material. Infinite chilled cast iron roll is a material between chilled cast iron and grey cast iron. There is graphite in the matrix structure of the working layer of the roll body, and there is no obvious dividing line between the working layer of the roll body and the core. Rubber rollers are such low-end rollers. Ordinary cast iron rolls are mainly used for rolling sheet mills, three-high mills, medium plate mills, wire rod mills, bar mills and profile mills.
Infinite chilled cast iron is a material between chilled cast iron and grey cast iron. There is evenly distributed graphite in the matrix structure of the working layer of the infinite chilled cast iron roll. The graphite content increases with the increase of the roller body surface to the inner depth, and the hardness decreases accordingly. Therefore, there is no obvious dividing line between the working layer of the roll and the roll core, which is also called the infinite chilled cast iron roll material with high chromium, nickel and molybdenum alloy elements. There are a lot of carbides in the matrix structure of the working layer of the high nickel-chromium infinite chilled cast iron roll body, so it has high wear resistance. The presence of graphite in the matrix structure makes it have good heat resistance and heat resistance, and is widely used as finishing rolls in wide, medium and heavy plate mills and strip mills.