GB2159079A

GB2159079A - Roll pass design

Info

Publication number: GB2159079A
Application number: GB08510500A
Authority: GB
Inventors: Hans-Jurgen Nowak
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1984-05-25
Filing date: 1985-04-25
Publication date: 1985-11-27
Also published as: JPH0763721B2; JPS60261602A; FR2568796A1; GB2159079B; DE3419501A1; GB8510500D0

Abstract

I- and U-section beams are rolled in a mill comprising a reversing blooming train and a subsequent continuous finishing train. The number of roll sets required in the blooming train for a given range of beam dimensions are reduced by providing a single leading pass in the blooming train which is capable of dealing with at least two and up to four finished section dimensions. <IMAGE>

Description

SPECIFICATION Roll pass design This invention relates to a roll pass design for rolling I- and U-section beams.

Such beam sections are rolled in a rolling mill constituted by a two-high reversing blooming train (the so-called breakdown stand), and a subsequent continuous finishing train. The finishing train has a plurality of universal stands, upstream of and between which are connected edgers. In order to roll a specific range of differing beam dimensions, it is usual to allocate, to each beam section, a separate leading pass on the stand of the blooming train. The beam sections are then rolled out, to the required finished dimensions, in the successive stands of the continuous finishing train. The rolling out of the leading pass, as the last pass of the reversing blooming train is called, takes place in three to five shaping passes in the stand of the blooming train, the exact number of shaping passes depending on the size of the section.

As it is necessary to provide, for each finished dimension, a leading pass adapted thereto, it goes without saying that, depending on the number of different leading passes, the same number of different sets of rolls for the breakdown stand of the blooming train have to be provided. A further set of rolls is also required for finishing operations in the workshop, and a further set of rolls in reserve.

This equipment inevitably involves high investment costs, to which very high storage costs are added.

The aim of the invention is to provide a roll pass design having a reduced investment cost, and which can roll out the entire beam range of a typical rolling mill in a more economical manner.

The present invention provides a roll pass design for rolling I-and U-section beams in a rolling mill constituted by a reversing blooming train and a subsequent continuous finishing train, wherein a single leading pass of the blooming train is provided for at least two and up to four finished section dimensions, the size of the web chamber of the leading pass corresponding substantially to the web width of the smallest finished dimension to be rolled, and the flange size corresponding substantially to the flange height of the greatest finished dimension to be rolled.

If the invention allows only a single leading pass to be performed in the breakdown stand at least for two finished dimensions, then it is possible at the same time to reduce the investment costs by at least half.

The advantage simultaneously arises that only half as many sets of rolls have to be stored for the blooming train, so the storage costs are reduced significantly. Finally, a further saving results from the fact that the roll-change times on the reversing stand of the blooming train are at least halved, as two to four sections are rolled with only one leading pass according to the proposal of the invention.

According to a preferred embodiment, marked edging of the flanges is effected for rolling the smaller finished dimensions in the edgers, and marked spreading of the webs is effected for rolling the greater finished dimensions, inside the continuous finishing train in each case.

To achieve marked spreading of the webs, it is proposed according to a further feature of the invention that the flange pitch of the horizontal rolls be at an inclination of from about 0.5" to 25 from stand to stand from the finishing train to the first universal stand. This marked pitch of the flange in the stand of the finishing train allows not only the marked spreading of the web of the large section dimensions, but also allows desirable finishing work by the horizontal rolls by turning to size and corresponding advance into the web chamber.

The invention will now be described in greater detail, by way of example, with reference to the accompanying drawing, the single figure of which is a schematic representation which compares the roll pass design of the invention with a conventional roll pass design.

A normal rolling schedule for a typical train arrangement proposed the following sections for the range of beams; iPE100to220 HEA100to160 INP 100 to 220 Further beam sections with dimensions in inches are added to this schedule, such as IWF joist and junior beams As a separate leading pass is rolled out on the breakdown stand for each beam section in this conventional rolling schedule, the leading pass being rolled out in the continuous train to the finished dimensions, the following sets of rolls are required for the breakdown stand: IPE 100 and 120 one set IPE 140 one set IPE 160 one set IPE 180 one set IPE 200 one set IPR 220 one set HE 100 and 120 one set HE 140 one set HE 160 one set Nine sets of rolls are, therefore, required for the entire beam rolling schedule, the equivalent dimensions in inches having been taken into consideration.

As one set of rolls has to be kept in the workshop, and one set of rolls in reserve in each case, a roll park of 27 sets of rolls, that is to say 54 rolls, is required.

The invention proposes that up to four section sizes, for example IPE 160 to 220, be rolled in the subsequent continuous finishing train when using a single leading pass coming from the breakdown stand. For example, the following sets of rolls would then be required for the same beam schedule: IPE 100 to 140 one set IPE 160 to 220 one set HE 100 to 120 one set HE 140 to 160 one set Thus, only four sets of rolls are required for the entire beam rolling schedule, the equivalent dimensions in inches having been taken into consideration.

The investment costs can thus be reduced by 2.25 fold, the storage costs are much lower, and the roll-change times for the breakdown stand can be shortened.

The combination of the leading passes for various finished dimensions in one leading pass in the breakdown stand necessitates corresponding adaptation of the universal roll pass design of the finishing train. A corresponding pass design is illustrated in the drawing for the example of the dimensions IPE 160 to 220 of the breakdown stand.

This pass design diagram shows that the leading pass dimensions of the beam range to be rolled receives different rolling treatments only in the finishing train, and a significant feature of this arrangement is that the beam IPE 160 experiences marked edging of the flanges (and only insignificant spreading of the web) in the first edger El,whereas the beam IP 220 is scarcely edged (but the web is markedly widened) in the first edger E7. This is continued in the universal passes, the universal passes U6 to U1 having increasing flange pitch of the horizontal rolls of 0.5 in the U6 train to 25 in the U1 train.

Claims

1. A roll pass design for rolling I-and U-section beams in a rolling mill constituted by a reversing blooming train and a subsequent continuous finishing train, wherein a single leading pass of the blooming train is provided for at least two and up to four finished section dimensions, the size of the web chamber of the leading pass corresponding substantially to the web width of the smallest finished dimension to be rolled, and the flange size corresponding substantially to the flange height of the greatest finished dimension to be rolled.

2. A roll pass design as claimed in claim 1, wherein marked edging of the flanges is effected for rolling the smaller finished dimensions in the edgers, and marked spreading of the webs is effected for rolling the greater finished dimensions, inside the continuous finishing train in each case.

3. A roll pass design as claimed in claim 1 or claim 2, wherein theflange pitch of the horizontal rolls of the continuous finishing train increases in a range of about 0.5 to 25c from train to train.

4. A roll pass design substantially as hereinbefore described with reference to, and as illustrated by, the accompanying drawing.