Forging method for forged steel supporting rolls used for rolling mill of large-scale wide thick plates

Abstract

The invention discloses a forging method for forged steel supporting rolls used for a rolling mill of large-scale wide thick plates. A double-vacuum steel ingot is adopted to manufacture the forged steel supporting rolls, wherein the weight of the double vacuum steel ingot is no less than 250 tons, an average diameter of an ingot body is no less than phi 3300mm, and the height of the ingot body is no less than 4000mm. The forging method comprises a first step of prepulling; a second step of upsetting: carrying out heat preservation on the steel ingot for 30-50 hours with the temperature of 1200-1250 DEG C, and then carrying out upsetting on the steel ingot on an open die forging hydraulic machine through adoption of an upsetting plate and a forging method of wide anvil forcing; a third step of carrying out drawing out on the steel ingot through adoption of a forge operation machine and a tilting gear and through the forging method of the wide anvil forcing; and a fourth step of distributing materials until completing is achieved according to a forging drawing. In the forging process, an as-cast structure of the steel ingot can be smashed, internal gaps can be forged and combined, metal inclusions and out-phase particles are dispersed, so that a workpiece can obtain a fine and even recrystallized grain structure and obtain a reasonable fiber distribution trend, and requirements on structure property of the support rolls by the support rolls of large-scale wide thick plates are met.

Description

technical field [0001] The invention relates to a forging method of a large forged steel backup roll, in particular to a forging method of a forged steel backup roll for a large wide and thick plate rolling mill. Background technique [0002] With the vigorous development of construction projects such as shipbuilding, west-to-east gas transmission, high-pressure vessels, oil exploration, and ocean development, the demand for wide and thick plates has increased significantly. For this reason, large-scale wide and thick plate rolling mills with a manufacturing capacity of 4000mm or even 5000mm or more are required . The delivery weight of the backup rolls of this large wide and thick plate mill is often 170 tons, or even more than 250 tons. The average diameter is at least φ3300mm, and the height of the ingot body is at least 4000mm. [0003] However, the existing 650 tons·m forging manipulator has a tonnage of about 250 tons for independently safely clamping the steel ingot...

AI Technical Summary

Problems solved by technology

However, due to the large size and heavy weight of the extra-large steel ingot required for forging large backup rolls, there are metallurgical defects such as coarse and uneven as-cast structure, segregation, porosity, shrinkage cavity, non-metallic inclusions and various structural inhomogeneities in the steel ingot. Very serious, unable to meet the requirements for manufacturing large backup rolls

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