DD252328A1 - METHOD FOR HOT-ROLLING STAFF-FORMED ROLLING MATERIAL - Google Patents

Abstract

Process for the hot rolling of rod-shaped rolling stock, which is applicable in rolling plants with H-V arrangement using a Umformwirksemen Laengszuges. The aim of the invention is to increase the Umformeffektivitaet in continuous hot forming of stabfoermigem rolling stock on rolling scales in block design and to achieve a flexible operation. The task is to use the forming effective Laengszuege to intensify the forming process at maximum Hoehenabnahme. According to the invention, this object is achieved by the fact that in a one-sided operation, wherein two rolling mills form a compact double rolling stand unit, a free inlet into the first gantry takes place, the outgoing cross section enters the second gantry with the assistance of the Laengsdruckkraefte from the first Geruest a bo / ho -The ratio0.5 for a guaranteed decrease in height of at least e60% and, as the thickened bar ends appear, the speed adjustment in the double rolling stand units is carried out in conjunction with the change in the height decrease in the first rack.

Description

Field of application of the invention

The invention relates to a method for hot rolling rod-shaped rolling stock using a forming effective longitudinal tension, which is applicable in rolling plants with H-V arrangement.

Characteristic of the known technical solutions

The targeted use of forming effective longitudinal tensile forces during hot rolling of rod-shaped rolling is already known. Thus, in the DD-PS 145233 and DD-PS 145716 proposals for the use of Längszugwalzens with respect to the variation of the Anstichlage, the caliber and the stitch sequences submitted. It is assumed that the Längszugorientierte influencing the continuous deformation of the rolling stock on the change in the roll gap height and the rolling speed of the Zugwälzstaffel belonging scaffolding is feasible. In this connection, DD-PS 227628 proposes system-side solution proposals for the use of the block design for longitudinal tension rolling. The shown solution of a rolling mill does not allow optimal utilization of all located within the Zugwalzstaffel scaffolding. In addition, the conditions necessary for the effective implementation of the rolling stock transmitted tensile forces are not given. At the same time, the thickened ends occurring during longitudinal drawing rolling can only be reduced to a limited extent with these possibilities.

Object of the invention

The aim of the invention is to increase the Umformeffektivität during continuous hot forming of rod-shaped rolling stock on Walzstaffeln in block construction and to achieve a flexible operation of the rolling mill.

Explanation of the essence of the invention

The invention is based on the technical object to use reinforced in the continuous hot forming of rolling stock with longitudinal tension in wire, fine steel and billet streets at maximum height decrease the forming effective longitudinal trains to intensify the forming process.

According to the invention, this object is achieved in that for hot rolling of rod-shaped rolling stock on the flat web in rolling mills with HV arrangement using a forming effective Längszuges in one-wire operation, a free inlet into the first frame and the expiring cross-section in each second frame a b _o / h _o ratio of b _o / h _o = 0.5 with guaranteed height reduction of at least ε = 60%. In this case, the inlet takes place in the second framework with the aid of longitudinal pressure forces from the first framework.

In a single-core operation form two rolling stands a compact double roll stand unit, wherein between two stands a minimum distance in the order of a roll diameter is present.

In order to minimize the thickened bar ends occurring the speed adjustment in the entire rolling mill in conjunction with the modified height decrease in each case in the first frame at a reinforced during the passage of the rolling stock or the -endes, short-term Höhenumformerhöhung completed.

The forming process between two stands takes place either under tension or without. By utilizing the natural cross-sectional defect reduction between two double roll stand units, the thickened ends can be shortened. With the use of scissors, which are arranged after each double roll stand unit, the thickened tips and ends can be scooped if necessary or in Haveriefall the rolling stock can be divided.

Using the deformation-effective longitudinal tension, an effective tensile transformation takes place in the process according to the invention, wherein a tensile stretch of at least \ _m = 1.3 can be achieved.

In the present method, the twin roll stand units can be arranged separately or also together with other double rolling stand units existing rolling mill sections or arranged in them, in which case a zuglosen coupling is present.

The method is particularly suitable for continuous rolling, since the proportion of thickened ends is negligible. The proposed method offers the following advantages:

- low tap temperature

- Increase of the piercing cross section

- increase the final rolling speed

- space and energy savings ~ *

- simple speed control

embodiment

The invention will be explained in more detail in the following embodiment.

On a block rolling mill, wherein two rolling mills form the billet, rod-shaped rolling stock with large height reduction is converted with the additional effect of transmitted over the rolling tensile forces. It is rolled with H-V arrangement using flat rollers.

The following stitch plan is used:

Stitch plan: T ₀₁ = 900 ⁰ C, C15, A ₀₁ = 180 χ 180mm ² , V = 10017h, V ₀₁ = 0,11m / s

without longitudinal tension 1.0 2nd framework with longitudinal train 1.3 2nd framework I.Gerüst 2,197 85 I.Gerüst 2,856 85 h / mm / 108 173.48 108 133.45 b / mm / 213.14 37.85 209.48 37.85 α ΓΙ 28.7 1,561 28.7 1,995 λ 1,407 'enforced 1,432 forced broaching • free free Ku

In the present process, the stretch is so great that two conventional scaffolds are saved. In addition, the use of longitudinal tensile rolling can improve the energy balance compared to the conventional forming process.

By stretching degree increasing measures during the passage of the thickened Walzgutspitze and desendes, as well as the short-term increase in the height deformation in the first frame and the simultaneous speed increase in the second frame (top) and the speed reduction in the first frame (end), the losses can Schopfverlusten to a minium be reduced.

Claims (3)

1. A method for hot rolling of rod-shaped rolling stock on the flat web in roll systems with HV arrangement using a forming effective longitudinal train, characterized in that in one-wire operation, with two rolling stands form a compact double roll stand unit, a free inlet into the first frame takes place, the expiring Cross section when entering the second frame with the aid of the longitudinal pressure forces from the first frame a b _o / h _o ratio of greater than _or equal to 0.5 with guaranteed height reduction of at least ε = 60% and the passage of the thickened bar ends occurring the speed adjustment in the twin rolling mill units in conjunction with the change in the height decrease in the first frame by an increased short-term Höhenumformerhöhung is completed. 2. The method according to claim 1, characterized in that a minimum distance in the order of a roll diameter is maintained between the two stands of the double roll stand unit. * 3. The method according to claim 1 and 2, characterized in that scooped up after each double roll stand scissors, the thickened ends and tips and in Haveriefall the wires can be divided.