A method for producing H-beams by splitting and rolling slabs with a universal rolling mill

Abstract

The invention provides a method for producing H-steel by chopping and rolling slabs with universal mills. The method comprises the following steps: firstly, a suitable slab is selected; then the slab is heated, is conveyed in front of a universal mill group through a roller bed, and is fed into the universal mills; each universal mill is of a hole-type structure formed by up-down horizontal rolls and left-right vertical rolls, wherein the up-down horizontal rolls are driving rolls, and the left-right vertical rolls are driven rolls; the up-down horizontal rolls first grab the slab and then drive the slab to pass through the powerless left-right vertical rolls; the left-right vertical rolls are provided with convex roll rings for cutting the slab; the slab is subjected to multiple steps of rolling of the multiple universal mills; and the angles of the roll rings of the vertical rolls of each universal mill are changed sequentially, so that the slab is milled into an intermediate blank of H-steel. The slab is clamped by the up-down horizontal rolls, so that the problem of cutting instability does not exist; blanks with small thickness can be cut; in a chopping and cutting process of the vertical rolls, along with the pressing of the horizontal rolls, the thickness at the waist part of the rolled slab is reduced at the same time; the extension coefficients of the whole rolled slab tend to be uniform; the internal stress is small; and the quality of products is high.

Description

technical field [0001] The invention belongs to the field of iron and steel manufacturing, in particular to a method for producing H-shaped steel by splitting and rolling slabs with a universal rolling mill. Background technique [0002] The production of H-shaped steel requires large-sized rectangular billets or special-shaped billets, and the production of large-sized rectangular billets or special-shaped billets requires a large continuous casting arc radius due to its high section height. Due to the large investment in large-arc continuous casting, H The production cost of section steel remains high. To produce H-beams, billets are necessary, and large-size billets are basically unavailable in the market, so the production process of traditional H-beams is as follows: steelmaking→continuous casting→rolling. That is to say, if there is no dedicated continuous casting, the production of H-beams is like cooking without rice. If slabs can be used to directly produce H-beam...

AI Technical Summary

Problems solved by technology

However, there are the following problems in the production process: 1) vertical rolling is required, and the steel bite is unstable, and the splitting is poor in neutrality; 2) in order to prevent the rolling pass from being unstable in the vertical rolling pass, the width-thickness ratio of the slab should not be too large, so it is necessary to Thick slab; 3) In the process of splitting, when the splitting of the rolled piece is completed, the thickening of the billet is accompanied by the thickening of the billet, resulting in a large amount of subsequent processing; at the same time, in order to compensate for the narrowing of the rolled piece caused by the thickening of the pier, a wider raw material needs to be selected 4) Due to the many forming passes, the temperature drop is very large; 5) After splitting, the legs of the rolled piece are thin and the waist is thick, while the requirement of the intermediate billet is that the legs are thick and the waist is thin. The small elongation coefficient of the waist and the large elongation coefficient of the waist make the internal stress of the joint of the waist and legs very large, the rolled piece is easy to warp, ripples are easy to occur, and the root is easy to crack

Due to the above problems, the two-roller BD machine was used to split and roll the slab to produce H-beams, which was finally declared a failure.

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