SU761037A1 - Method of producing flanged sections - Google Patents

Description

The invention relates to rolling production and can be used when rolling flange (I-beams, channel bars, ball pullets, pan, etc.) profiles on section rail-beams and specialized beam mills.

In modern rolling production, flange profiles are obtained by gradual reduction from the passage to the passage of the initial billets of square, rectangular and shaped section in the system of closed, half-open and four-roll calibers [1].

Known rolling methods do not allow to obtain flanged profiles of increased accuracy, since the profile wall in the finishing and intermediate passages is assumed to be of the same thickness over the entire width.

By virtue of a smaller section, but a larger perimeter, the wall temperature is 150-250 ° C lower than the temperature of the flanges, and this, in turn, sharply worsens the plastic properties of the metal of the wall.

A known method of manufacturing flange profiles by rolling a profile billet in calibrated rollers in several passes with crimping flanges and walls to a predetermined thickness [2].

2

In this method, the workpiece has a variable wall thickness, the wall thickness in the middle section of the width is greater than in the places of mating with flanges.

5 However, this method cannot contribute to obtaining profiles of increased accuracy, since, on the one hand, the temperature difference between the wall and the flanges decreases in the middle part, remaining

Yu is the same at the mating site, and, on the other hand, an increase in compression in the middle part of the flanges leads to the appearance of such a defect as a “wave” (corrugation) along the wall.

15 In addition, the uneven deformation of the wall cannot completely exclude the zones of increased compression in the area of the wall transition to the flange, contributing to the wear of the gauge and obtaining increased

20 profile accuracy, since the wear of the gauge should be considered as a result of the transverse, rather than the longitudinal flow of the metal, which is practically impossible to eliminate by the method under consideration.

25 The aim of the invention is to improve the accuracy of the finished profile and reduce the wear of the gauge by reducing the difference in temperature compressed along the sections of the profile.

761037

3

This goal is achieved by the fact that the proposed method of manufacturing flange profiles by rolling a profile billet in calibrated rollers in several passes with crimping 5 flanges and walls to a given thickness, according to the invention, the middle wall section is compressed in one pass to a given thickness, and in subsequent passes on the other hand, sections of the wall that are increasingly approaching the flanges are subjected to compression, while on the non-compressible wall sections they leave a wall gap with a caliber surface for compensators. and metal broadening.

The final width of the wall is obtained by gradually reducing the uncompressed areas from the passage to the passage. The principal difference between the proposed operation and the known one is that the main wall formation in a single pass in a limited area is carried out in elevated temperature zones, as a result of which the accuracy of obtaining flange profiles is significantly increased.

FIG. 1 shows the shape of the shaped blank by a known method (I-profile); in fig. 2 - preparation of the proposed method; in fig. 3 - the location of the roll in the subsequent caliber.

Beam No. 36 at the Azovstal plant is rolled from a billet of 320x320 mm with a straight wall from a duo crimping stand in the first calibers of the 800 trio stand. Measurements 15 found that in the second caliber the temperature of the wall and flanges (on average section) at thicknesses of 21.4 and 21.7 mm, respectively, is almost the same and is equal to 1080 ° C. It was decided, starting with the third 20 gauge, to change the configuration. New roll calibration gave the following results, which are tabulated.

Purpose processing Processing mode,% Temperature treatment of the wall, ° C 3 caliber four caliber five caliber 6 caliber 7 caliber 3 caliber four caliber five caliber 6 caliber 7 caliber Known method 0 0 0 0 20.2 1065 1030 1000 940 890 wall processing 21.5 19.2 15.7 13.3 ί 10.1 The proposed method of processing the wall 0 0.1 0.2 0.3 0.4 1070 1060 1045 1020 1000 67.3 67.5 67.7 68.0 68.4

Note. For a known method, a minator for an equal wall.

at

numerator shows deformation

given the 'thickening,

For the proposed method, in the numerator the magnitude of the metal broadening in the compensator (gap) is shown, and in the denominator the magnitude of the wall reduction in a limited area, taking into account the broadening of the metal in the compensator (gap).

The use of the proposed method of rolling flange profiles in comparison with existing ones provides the following advantages:

the possibility of obtaining flanged profiles of high accuracy;

reliable preservation of high temperature rolling conditions of the thinnest cross-section, but large along the perimeter of the profile-wall element;

completely eliminates high compression zones, which determine the wear of gauges and the accuracy of the profile, and thereby increases the service life of the replacement equipment, which improves the productivity of rolling units.

Claims (1)

Claim A method of manufacturing flange profiles by rolling a profile billet in calibrated rollers in several passes with crimping flanges and walls to a predetermined thickness, characterized in that, in order to improve the accuracy of the finished profile and reduce the wear of the gauge by reducing the temperature difference between the sections of the profile compressed along the aisles walls are compressed in a single pass to a predetermined thickness and, in subsequent passages, sections of the wall that are increasingly approaching the flanges are subjected to the same compression, while and the uncompressed wall sections leave a wall gap with the surface of the caliber, to compensate for the broadening of the metal.