Process for manufacturing large high-chromium medium-carbon alloy forging back-up rolls

Abstract

The invention relates to a process for manufacturing large high-chromium medium-carbon alloy forging back-up rolls. The process includes the steps: firstly, forging a blank after smelting alloy steel and annealing the forged blank; secondly, performing rough turning, semi-fine turning and fine turning; and thirdly, polishing the forged blank to obtain a finished product. The large back-up rolls are manufactured by means of advanced full-automatic numerical control differential-temperature integral quenching heat treatment process, the hardening depth of each large back-up roll reaches and exceeds 100 millimeters, hardness uniformity of roll bodies is within two Shore hardness units, and the weight of a single roll exceeds that of each large back-up roll of 25 tons. The practical service lift of the rolls is greatly prolonged, roll consumption is reduced, production cost is saved, and high-precision wide strips with even and smooth rolled plate surfaces can be used for automobile manufacture, space shuttle and national defense industry.

Description

technical field [0001] The invention relates to the field of support rolls, in particular to a manufacturing process for large-scale forged support rolls of high-chromium and medium-carbon alloys. Background technique [0002] With the continuous launch of domestic large-scale strip projects, the demand for large-scale back-up rolls for cold tandem mills has increased, but large-scale special equipment is required for its manufacture, and the processing and manufacturing cycle is long. Generally, it takes 8 to 12 months for the production process. At present, domestic Such large back-up rolls are highly dependent on imports and have high value, and have a long online life cycle and cannot be rotated off-line regularly. Therefore, abnormal failure or normal scrapping will have a great impact on the cost control and resource utilization of the user unit. Plants and roll manufacturing plants are key management products. [0003] At present, the large support rolls manufactured...

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Problems solved by technology

[0002] With the continuous launch of domestic large-scale strip projects, the demand for large-scale back-up rolls for cold tandem mills has increased, but large-scale special equipment is required for its manufacture, and the processing and manufacturing cycle is long. Generally, it takes 8 to 12 months for the production process. At present, domestic Such large back-up rolls are highly dependent on imports and have high value, and have a long online life cycle and cannot be rotated off-line regularly. Therefore, abnormal failure or normal scrapping will have a great impact on the cost control and resource utilization of the user unit. Plants and roll manufacturing plants are key management products

[0003] At present, the large support rolls manufactured in China, due to the poor hardenability of the material, affect the depth of surface hardening. Generally, the effective use depth does not exceed 50mm. The actual service life of the roll is limited, and the hardness of the roll surface is uneven, more than 5 Xiao Hardness unit, resulting in poor flatness and smoothness of the rolled strip surface, unable to produce high-precision strips

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