Preparation method of high-speed steel roller for headless strip steel rolling finish rolling rear section

Abstract

The invention discloses a preparation method of a high-speed steel roller for a headless strip steel rolling finish rolling rear section. The preparation method comprises the following steps of performing three-layer centrifugal composite casting, correspondingly casting an outer layer, a middle layer and a core part through using high-strength nodular cast iron, controlling the content of castingmolten steel of the middle layer and the core part to comprise the following components of 1.8 wt%-2.8 wt% of C, 0.6 wt%-0.9 wt% of Si, 0.5 wt%-0.8 wt% of Mn, 0.4 wt%-0.8 wt% of Ni, less than or equal to 0.03 wt% of P, less than or equal to 0.03 wt% of S, 17 wt%-22 wt% of Cr+Mo+Nb+V+W and the balance Fe and inevitable impurities. According to the method, graphite obtained on the outer layer reduces the friction coefficient, a certain number of hard carbides enhance the wear resistance of the roller, and therefore such structure can effectively reduce damage of tail frame drifting to the roller; and meanwhile, the middle layer and the core part are subjected to methods of wire feeding spheroidizing and wire feeding inoculation (two wires for each method, so that four wires are fed at the same time), in this way, the nodulizing grade and tensile strength of the nodular cast iron are improved, and accident resistance of the roller can be greatly enhanced.

Description

technical field [0001] The invention belongs to the field of iron and steel casting, and in particular relates to a method for preparing a high-speed steel roll used in the rear section of endless strip steel rolling and finish rolling. Background technique [0002] At present, although high-speed steel rolls have been used on hot-rolled strip steel, most of them are used in the front section of finish rolling (F1-F3 or F1-F4), and a small amount are used in rough rolling, and after finish rolling. At present, high-nickel-chromium infinitely chilled rolls are generally used, and the use of high-speed steel in the rear frame is almost blank. However, with the continuous adjustment of the product structure of the steel industry, the requirements for rolled materials continue to increase, such as rolling high-performance silicon steel. Higher requirements are put forward for the wear resistance of the roll and the maintenance of the roll shape for products such as automobile sh...

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Problems solved by technology

[0004] However, the performance requirements of the work rolls required by the ESP rolling line are very high, and the single online time is long. Generally, the single pass of the hot strip continuous rolling mill is about 50 kilometers, while the single pass of the ESP hot rolling line is 150 kilometers. Kilometers, sometimes even more, is about three times the mileage of a single rolling of ordinary rolls; at the same time, the thickness of the general ESP rolled material is concentrated at about 0.8-1.1mm, which is difficult and demanding to roll. Accident downtime will lead to the shutdown of the entire production line, which requires rolls to have super wear resistance and roll shape retention capabilities, as well as strong accident resistance, which requires us to continue to study new high-speed steel roll materials to meet the needs of rolling mills. line usage requirements

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