Improved nickel chromium molybdenum inlimited cold hard cast-iron for roller and its compound roller

Abstract

This invention relates to an improvement of NiCrMo infinite cooling hard cast iron used in roll materials of metal machining hot rolling and cold rolling plate, especially relates to a kind of NiCrMo infinite cold hard cast iron used in roll with excellent wear resistance and thermal crack resistance property, long longevity, the character is adding 0.03-0.1%(WT) B and 0.2-1.5% Nb in the component of NiCrMo infinite cold hard cast iron. As well as the composite roll made from this materials. Because of the addition of B and Nb, the wear resistance and thermal crack resistance property are remarkably improved, which overcomes the disadvantage of raw materials. The operating life of composite roll whose working layers are made from this materials is enormously improved compared with original life. The plate band rolling amount increases more than 20%; the improvement of thermal crack resistance property.

Description

technical field [0001] The present invention relates to the improvement of the roll material used for metal processing hot rolling and cold rolling strips - nickel chromium molybdenum infinite chilled cast iron, especially relates to a kind of nickel for rolls with good wear resistance and thermal crack resistance and long service life Chromium molybdenum infinite chilled cast iron and composite rolls made of this material. Background technique [0002] The existing roll material for hot rolling and cold rolling of strips - nickel-chromium-molybdenum infinite chilled cast iron (IV) (GB / T1504-91), the composition is: C: 2.90-3.70%, Si: 0.60-1.20%, Mn Ni: 0.40-1.20%, Ni: 3.01-5.00%, Cr: 1.00-2.00%, Mo: 0.20-0.60%. Because the graphite is in the form of flat strips and the carbides are in the form of a network, the matrix strength of this material is relatively low. Therefore, in actual use, its wear resistance is still insufficient and the service life is not long (mm rolling...

AI Technical Summary

Problems solved by technology

Because the graphite is in the form of flat strips and the carbides are in the form of a network, the matrix strength of this material is relatively low. Therefore, in actual use, its wear resistance is still insufficient and the service life is not long (mm rolling amount 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. The increase 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 replacement operation intensity, and the repair workload; but also affects the surface quality of the rolled strip, and the repair of thermal cracks also reduces the service life of the roll, resulting in higher production costs

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