Chilled cast iron contains almost no free graphite in the matrix of working layer of the barrel. The microstructure is fine pearlite and carbides. It has a high hardness and excellent wear resistance. It is suitable for finishing stands of light bar and wire-rod rolling mills and narrow strip mills.
High Cr iron has a high hardness and outstanding wear-resistance in high temperature, by controlling the chemical composition and heat treatment process, the hardness of working layer of roll barrel can reach 80-85HSC, there is complex carbides of vanadium, wolfram, niobium, molybdenum in matrix of martensite, which commits homogeneous hardness throughout the working layer, and even wear in grooves.
Roll produced by forging steel ingot. Forging can forge the metallurgical defects such as porosity and shrinkage cavity in the ingot, break the coarse casting structure, and obtain high-quality rolls with dense structure and uniform composition. Forged steel rolls have better strength and toughness, surface hardness uniformity and fatigue resistance than similar cast rolls. (Table 1) in order to meet the specific requirements of different rolling mills and rolling conditions, different alloy elements can be added to the roll steel to improve the roll performance. A certain amount of carbon and alloy elements have the following different effects on the structure and properties of forged steel rolls: carbon can increase the hardness and strength of rolls, reduce plasticity and improve wear resistance; Manganese can increase hardenability and strength; Silicon deoxidizes and improves strength; Chromium can increase hardenability, strength and wear resistance; Molybdenum can increase hardenability, strength and thermal hardness; Vanadium can control the grain size of steel and increase the strength. See Table 2 for the main chemical composition of common forged steel hot rolls and backup rolls.
Alloy Indefinite Chilled is cast iron with fine inter-crystalline graphite evenly distributed throughout the working layer of roll barrel.The sizes, shapes and distributions of graphite and carbide are controlled by the chilling effect and the contents of alloy elements.The addition of alloy elements such as Mg,Ni,Cr,and Mo changes the matrix from pearlite and bainite to martensite. Plus the present of small amount of fine graphite, the performance of spalling resistance, thermal crack resistance and wear resistance were enhanced significantly. The material has small hardness gradient in the working layer of roll barrel and is suitable for intermediate and finishing stands for bar,wire and section mills.
Paper-making cots are cots used for papermaking. According to the structure, they can be divided into smooth roll (flat roll, no pattern on the surface), groove roll, screw roll, vacuum roll, movable arc roll (hollow bending roll) and medium high roll. It is used in different parts of the paper machine to squeeze water, press and polish.
Papermaking cots are cots used for papermaking. According to the structure, they can be divided into smooth roll (flat roll, no pattern on the surface), groove roll, screw roll, vacuum roll, movable arc roll (hollow bending roll) and medium high roll. It is used in different parts of the paper machine to squeeze water, press and polish. A long net paper machine usually has 70 or 80 rubber rollers of different sizes. According to the structure, it can be divided into smooth roll (flat roll, no pattern on the surface), grooved roll (groove on the surface of the coating), threaded roll (thread groove on the surface of the coating), vacuum roll, movable arc roll (hollow bending roll) and medium high roll. It is used in different parts of the paper machine to squeeze water, press and polish. Generally, it is made of various Sr (such as PU, etc.).
High Speed Steel roll has a high hardness and outstanding wear-resistance in high temperature, by controlling the chemical composition and heat treatment process, the hardness of working layer of roll barrel can reach 75-95HSD, there is complex carbides of vanadium, wolfram, niobium, molybdenum in matrix of martensite, which commits homogeneous hardness throughout the working layer, and even wear in grooves. Chemical composition
Graphite Steel (GST)
The character of graphite steel roll is similar to that of adamite roll. The main character is that it contains a small amount of fine graphite in its micro-structure, which increases its resistance to fire-crack and prevent oxidized scales from adhering. Thus making it suitable for blooming and roughing stands.
Alloy steel formed by adding some alloy elements into the common carbon steel, through heat-treatment process, the good performance of wear-resistance and toughness can be achieved. It is widely used for backup/roughing roll for plate/strip mill and backup
roll for leveling mill, Roughing roll for plate/section/bar & wire-rod mill; Break-down roll for rail beam/universal section mill; Descaling/roughing/backup/vertical roll for strip mill.
High chrome steel contains a lot of Cr, Ni, Mo and other alloy elements in the liquid metal. When the liquid metal solidifies, the carbide precipitated in the matrix structure is M7C3 eutectic carbide, , so it has good wear resistance.
These kind of rolls are mainly for grain and oil, foodstuff, with special alloy content in white iron and grey iron, makes it good for applications, our manufacturer has participated in grain rolls standard drafts and compiles, which has good experience and high cost performance.
SGA rolls are widely used in intermediate stands and finishing stands, due to it's stable quality, and better strength, toughness and wear resistance. In normal steel rolling process, it has no rolling accident, no breakage, in most of severe situation, mills used for replacing AIC rolls.
Material C Si Mn Cr Ni Mo
SGAâ? 2.90~3.60 1.20~2.20 0.20~0.80 0.20~1.00 3.01~3.50 0.50~1.00
SGAâ?¡ 2.90~3.60 1.00~2.00 0.20~0.80 0.30~1.50 3.51~4.50 0.50~1.00
Adamite is a material that has both high strength and toughness of cast steel and good wear-resistance and hardness of cast iron. Due to its alloy elements such as Si, Ni, Cr, Mo etc, and some amount of carbides in the matrix, through a certain of special heat treatment technology, making it has a good wear-resistance and toughness. AD roll also has small amount of hardness drop and deep cutting depth.
Cemented carbide roll ring (also known as tungsten carbide roll ring) is a roll made of tungsten carbide and cobalt by powder metallurgy. There are two types of cemented carbide rolls: integral and combined. Superior performance, stable quality, high machining precision, good wear resistance and high impact resistance. Cemented carbide roll has been widely used in the production of rod, wire rod, deformed steel bar and seamless steel pipe due to its good wear resistance, high temperature red hardness, heat fatigue resistance and high strength, which greatly improves the effective operation rate of the rolling mill. According to the difference of working environment of each stand roll, various kinds of cemented carbide roll rings of different grades have been developed, which are mainly used for finishing rolling block.
