What are the types and characteristics of cast iron rolls?

2022-01-17 09:31

Cast iron roll is an important part of the rolling mill in the rolling mill. The pressure generated by a pair or group of rolls is used to roll the steel. It is mainly affected by dynamic and static load, wear and temperature change during rolling. There are many kinds of rolls. The commonly used types of rolls include cast steel rolls, cast iron rolls and forged rolls. Today, let the roll manufacturer Wuxi Taihu roll editor bring you an explanation of the types and characteristics of cast iron rolls.




(1) Alloy chilled cast iron roll




Alloy chilled cast iron roll uses the method of undercooling of molten iron itself and chilling of cold shape appearance to generate white layer. There is basically no free graphite in the matrix structure of roll body operation layer. The metallographic structure is fine pearlite and carbide, which has high hardness and excellent wear resistance. U it is used in small rod and wire mill and narrow band steel finishing mill.


Cast iron roll

(2) Alloy infinite chilled cast iron roll




Alloy infinite chilled cast iron roll is a kind of material between chilled cast iron and gray cast iron. There is uniformly distributed graphite in the matrix of the working layer of the infinite chilled cast iron roll body. The content of graphite increases with the increase of depth from the outside to the inside of the roll body, and the hardness decreases with it. Therefore, there is no obvious boundary between the working layer of the roll body and the core. When the material of infinite chilled cast iron roll contains high chromium, nickel and molybdenum alloy elements, it is a high nickel chromium infinite chilled cast iron roll, which is produced by full flushing (overflow method) or centrifugal compound pouring process. There are many carbides in the matrix structure of the working layer of the roll body of high nickel chromium infinite chilled cast iron roll, so it has high wear resistance. The existence of graphite in the matrix structure makes it have excellent thermal crack resistance. It is widely used as the finishing roll of wide, medium and heavy plate mills and strip mills.




(3) Alloy nodular cast iron roll




The characteristic of this kind of roll is that the graphite is spherical and evenly distributed from the roll body to the core, so it has high tensile strength, can be full of heavy load and good wear resistance. The matrix structure is carbide and pearlite or acicular bainite. Alloy nodular cast iron roll can be divided into Pearlite Nodular Cast iron roll and bainite nodular cast iron roll according to the matrix structure of roll body. Alloy nodular cast iron roll has excellent thermal shock resistance and wear resistance. It is widely used as roll for large blooming mill, section steel mill, bar continuous mill and large seamless pipe mill.




(4) Pearlite ductile iron roll




Pearlite Nodular Cast iron roll is obtained by adding chromium, nickel and molybdenum alloy elements into nodular cast iron roll and special heat treatment. Pearlite ductile iron roll has excellent strength, high temperature performance and anti accident performance, and the hardness drop of the working layer is small.




(5) Acicular bainite ductile iron roll




The nodular cast iron roll contains alloy elements such as nickel, manganese, chromium and molybdenum. It is a matrix with acicular structure (bainite + a small amount of martensite). It has higher strength, better resistance and significantly improved wear resistance than Pearlite Nodular Cast iron roll. It can be produced by static casting and centrifugal casting, but due to the high alloy content and large casting stress of acicular bainite nodular cast iron roll, the centrifugal compound casting process can obtain ideal comprehensive performance.

Cast iron roll

(6) High chromium composite cast iron roll




Wear resistant high chromium white cast iron containing 12% ~ 22% chromium is used as the outer material of roll body, and nodular cast iron is generally used as the material of roll core and roll neck. The high alloy composite cast iron roll is produced by centrifugal composite casting process. Due to the existence of strip like M7C3 eutectic carbide, chrysanthemum like M2C eutectic carbide and granular M23C6 secondary carbide in the matrix, high chromium composite cast iron roll has excellent wear resistance and is widely used as roughing and finishing operation roll of hot strip continuous rolling mill, roughing and finishing operation roll of wide, medium and heavy plate rolling mill and finishing operation roll of small section steel and plate rolling mill.




The above is a brief introduction to the types and characteristics of cast iron rolls. Next, Xiaobian will continue to share the relevant contents of cast iron roll with you. If you are interested, you are welcome to pay attention to Wuxi Taihu roll Xiaobian.