Manufacturing technique and device for improved bainite nodular cast iron composite roller provided with forged steel roller neck

Abstract

The invention discloses a manufacturing technique and device for an improved bainite nodular cast iron composite roller provided with a forged steel roller neck. The improved bainite nodular cast iron composite roller provided with the forged steel roller neck is prepared from, by mass, 3.0%-3.6% of C, 0.60%-1.20% of Si, 0.30%-1.20% of Mn, 3.0%-5.0% of Ni, 1.0%-2.0% of Cr, 0.40%-1.2% f Mo, 0.1%-2% of W, 0.5%-1.0% of Cu, 0-0.05% of P, 0-0.30% of S, 0.04%-0.06% of Mg, 0.1%-0.3% of Nb, 0.1%-0.30% of Ti, 0.2%-0.6% of V, 0.05%-0.2% of B, 1.5%-2.5% of Ba, 1%-2% of Ca, 1%-3% of Sb, 0.02%-0.18% of N, 1.0%-2.0% of Y / RE, and the balance Fe and inevitable trace elements. According to the manufacturing technique and device for the improved bainite nodular cast iron composite roller provided with the forged steel roller neck, yttrium-based rare earth is used for nodularization, Ba, Ca and silicon iron are used for combined inoculation, Nb, Ti, V, B and Sb are added for modification treatment, and thus the mechanical property of the roller is improved; by the adoption of the forged steel roller neck, the strength of the roller is improved; integral in-mold heating and casting of a core rod are conducted through an induction heater, and a water-cooling crystallizer is used for formation; the interface of a composite layer can be controlled dynamically, the technique is simple, power consumption is low, the cost is low, composition segregation is avoided, and the service life of the roller is long.

Description

Technical field [0001] The invention belongs to the technical field of metal pressure processing, and in particular relates to a manufacturing process and equipment for an improved forged steel roll neck bainite ductile iron composite roll, which is suitable for the manufacture of composite rolls in the steel rolling industry. Background technique [0002] Rolls are known as the "mother of steel". They are tools for plastic deformation of metal materials in the rolling production of steel, aluminum, copper and other metals. It is an important large-scale component that determines the production efficiency of the rolling mill and the quality and economy of the rolled material. The consumption cost of rolling indispensable key components and the most important bulk consumable components is about 5% to 15% of the rolling production cost. If you consider factors such as production downtime, reduced production, and increased equipment maintenance due to roll consumption, the proportio...

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Problems solved by technology

Therefore, when the core material is cast steel, a good composite interface cannot be obtained.

[0012] 3) Composite rolls with forged steel cores with high strength and high toughness cannot be produced

At present, it is mainly manufactured by the centrifugal composite casting process in China. Due to the limitation of the manufacturing process, the core is made of nodular cast iron. Due to the low strength of nodular cast iron, it is easy to break the roll during steel rolling production, which seriously affects the steel rolling production and product quality.

[0023] At present, centrifugal bainite rolls are usually used in the rolling of finished bars, slitting racks, and strips. This roll has the following shortcomings in the long-term use process: 1. The hardness drop is large, and the centrifugal bainite rolls From one use to the last use, the material structure changes greatly, the hardness and wear resistance decrease rapidly, and the rolling tonnage can decrease by 50-70 tons; 2. The thermal fatigue resistance is poor, and the rolls work at high temperature for a long time. Due to the thermal fatigue resistance of the roll, after a period of use, the roll is prone to cracks and surface blocks, which seriously affects the quality of the rolled piece; 3. The centrifugal bainite roll has low toughness and high brittleness, and roll breakage occurs from time to time

Moreover, because the graphite is in the form of flat strips and the carbides are in the form of a network, the matrix strength is relatively low. Therefore, in actual use, its wear resistance is still insufficient, and the service life is not long (the rolling amount of mm is generally 2000~ 3000 tons); secondly, due to the network structure of carbides and the boundary effect of graphite voids, the thermal crack resistance of the material is also poor, and the rolled rolls produced during the strip rolling process, with the rolling The increase of the amount will cause thermal cracks, so it is necessary to stop frequently to replace the roll, remove it for repair

It not only affects the shift production efficiency of the rolling mill, increases the intensity of replacement operations, and the workload of repairs; but also affects the surface quality of the rolled strip, and the repair of thermal cracks also reduces the service life of the rolls, resulting in higher production costs

The above problems lead to the short service life of centrifugal bainite rolls, which cannot meet the production requirements of high-efficiency rolling mills

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