SU789167A1 - Bar billet rolling method - Google Patents

Description

The invention relates to metallurgy, and in particular to a technology for the production of high-quality billets on rolling mills.

A known method of hot rolling of various profiles, consisting in the simultaneous parallel rolling of several profiles with the leaving between them of refined sections along their entire length and subsequent separation from each other 11].

The disadvantage of this method is the increased wear of the separating crests of the rolls forming a thin jumper, and, therefore, the deterioration of the quality of separation as the crests wear.

A known method of rolling high-quality billets ¹ wok, including rolling a slab into several threads joined together and their subsequent separation [2].

The disadvantages of this method are the increased wear of the separating ridges of the rolls forming a thin bridge, especially sharp ridges, and the deterioration of the quality of the divided workpieces in the zones of the jumpers.

The purpose of the invention is to increase the durability of the work rolls by reducing wear of the separating crests of the rolls and improving the quality of the workpieces in the separation zones.

The goal is achieved by the fact that between the passes locally deform the zones of the future separation of the workpieces, and the degree of local deformation is chosen so that in the next pass in the zones of separation of the workpieces, it does not exceed 10%.

In addition, the width of the zone of local deformation is chosen equal to (0.04 — O, 25) C, where C is the step between the streams along the ridges of the work rolls.

In FIG. 1 shows a multi-grooved roll rolled in caliber; in FIG. 2 is a diagram of local deformation; in FIG. 3 - multi-groove roll in η + 1 caliber; in FIG. 4 - zone of local deformation after η caliber; in FIG. 5 - the same, in η + 1 caliber.

Work rolls 1 and 2 (Fig. 1) form a multi-groove gauge, where they form a roll 3 with a predominant deformation in the zones of future jumpers 4. After the roll comes out of the η gauge, the roll is deformed (Fig. 2) using rollers 5 and 6 located outside the work rolls in zones 7. Moreover, depending on the width of the rollers and the magnitude of the degree of local deformation, the rollers can be driven or idle. At small degrees of deformation in narrow rollers, the deformation is carried out due to the energy of the drive of the work rolls, and at the exit from them - due to the inertial forces of the roll and the friction forces (pulling force) of the roller table. Rolling in n + 1 gauge is accompanied by a lower degree of deformation in the compression zones by rollers than in the rest of the caliber perimeter. When rolling-separation in a continuous billet mill, local deformation is most preferably carried out with canting. rolls in the interstand spaces, using the drive energy of the work rolls.

It is known that wear of the cutting ridges of the work rolls prevails over wear in the rest of the caliber. An analysis of experimental wear plots, for example, according to [3], shows that in gauges of the split type use stop. rykh crests quickly destroys the caliber.

Preferred wear is most noticeable in the range (0.1-0.4) K, where K is the width of the crest of the split gauge. Given the geometrical analogy of a multi-grooved caliber with a split one, this range is (0.04-0.25) C, where C is the step between the streams along the ridges of the work rolls. Especially important is the fact that the loss of the shape of the crest in a multi-armed caliber is more dangerous than in a conventional split, which is always a draft caliber.

The minimum value of 0.04 is limited by the actual design parameters of the rollers. In addition, the stress-strain state diagram along the ridge axis causes tensile stresses that reduce the strain energy in this zone.

The maximum value of 0.25 is limited by the reduction in the difference in wear over the ridge relative to the average caliber wear.

The efficiency of the multi-strand rolling process depends on the distribution of the degree of deformation over the passes. The average degree of deformation is always above 10%. Therefore, choosing

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Example p. Multi-strand rolling of a 135 mm square constructed is carried out from a 250x500 mm slab in a reverse stand with rolls with a diameter of 920 mm for 7 passes (the last one being the 5th separating one).

After the fifth pass, the jumper thickness is 30 mm. At the exit of the rolls, a set of two pairs of rollers with a diameter of 400 mm and a width of each 30 mm was installed. The upper and lower pairs of rollers are mounted on one common axis, have a degree of freedom in the axial direction and are oriented along the troughs on a three-strand roll. Compression in the sixth pass by work rolls - 10 mm. Hence, the 15th degree of deformation without crimping by rollers is 1.5. The average degree of deformation in height of the stream is 1.05. Compression by rollers on both sides of the roll, necessary to ensure the degree of deformation along the ridge 1.1, is. 2Q 8 mm. The average roller compression is 4 mm.

The loads arising on the rollers as a result of deformation do not exceed 3-5% of the loads on the work rolls.

Claims (3)

The invention relates to metallurgy, and generally to the technology for the production of high-grade billets on rolling mills. There is a method of hot rolling various profiles, consisting in simultaneous parallel rolling of several profiles, leaving between them refined sections along their entire length and subsequent separation from each other 1. The disadvantage of this method is the increased wear of the separating ridges of the rolls forming a thin web, and, consequently, the deterioration of the quality of separation as the ridges wear. There is a known method of rolling billet billets, which includes rolling the slab into several threads joined together and then separating them 2. The disadvantages of this method are increased wear of the rolls separating the ridges forming a thin web, especially sharp ridges, and deterioration of the separated billets in areas jumpers. The purpose of the invention is to increase the durability of the work rolls by increasing the wear of the separating ridges of the rolls and improving the quality of the blanks in the separation zones. The goal is achieved by the fact that between the gaps the zones of the future separation of blanks are locally deformed, and the degree of local deformation is chosen so that in the next pass in the zones of separation of the blanks it does not exceed 10%. In addition, the width of the local deformation zone is chosen to be (0.04-0.25) C, where C is the step between the strands along the ridges of the work rolls. FIG. 1 shows a multi-roll roll rolled in a caliber; in fig. 2 - local deformation scheme; in fig. 3 - multi-ripple in p + I caliber; in fig. 4 - zone of local deformation after n gauge; in fig. 5 - the same, in n + 1 caliber. The work rolls 1 and 2 (Fig. 1) form a multi-groove caliber, where they form the roll 3 with the predominant deformation in the zones of the future bridges 4. After the roll out of n gauge, the roll is deformed (Fig. 2) with the help of the rollers 5 and 6, located outside the workers rolls in zones 7. Moreover, depending on the ishrins of the rollers and the magnitude of the degree of local deformation, the rollers can be driven or idle. At small degrees of deformation in narrow rollers, the deformation is carried out due to the drive energy of the work rolls, and at the exit from them - due to the inertial forces of the roll and the frictional force (drag) of the roller table. Rolling in n + 1 caliber is accompanied by a lesser degree of deformation in the areas of reduction with rollers than in the rest of the perimeter of the caliber. When rolling-separating under the conditions of a continuous-billet mill, it is most preferable to carry out a local deformation by means of turning. rolls in interstand intervals, using the energy of the drive work rolls. It is known that the wear of the cutting ridges of the work rolls prevails over the wear of the rest of the caliber. Analysis of experimental plots of wear, for example, according to data 3 shows that in gauges of the type of cutting use ryh crests quickly caliber caliber. Predominant wear is most noticeable in the range (0.1-0.4) K, where K is the width of the ridge of the split caliber. The pin of the geometric analogy of a multi-rifle caliber with a split, this range is (0.04-0.25) C, where C is the step between ruts along the ridges of the work rolls. Especially important is the fact that the loss of the ridge shape in a multi-gauge caliber is more dangerous than in the usual split caliber, which is always a draft gauge. The minimum value of 0.04 is limited by the actual design parameters of the coke role. In addition, the stress-strain state along the ridge axis causes tensile stresses that reduce energy and strain in this zone. The maximum value of 0.25 is limited by a decrease in the wear gradient along the ridge relative to the average wear size for the gauge. The effectiveness of the multi-strand rolling process depends on the distribution of the degree of deforming through the passes. Average, the degree of deformation is always higher than 10%. Consequently, choosing the degree of deformation of the areas of bunkers with work rolls of not more than 10%, it is possible to eliminate the preferential wear of the ridges. 74 Example r. Many-hand rolling of a built-in square of 135 mm is carried out from a slab of 250x500 mm in a reversing stand with rolls with a diameter of 920 mm for 7 passes (the last pass being the separating one). After the fifth pass, the lintel thickness is 30 mm. At the exit of the rolls, a set of two pairs of rollers with a diameter of 400 mm and a width of 30 mm each is installed. The upper and lower pairs of rollers are planted on one common axis, have a degree of freedom in the axial direction and are oriented along the hollows on the three-strand roll. Obzhashe in the sixth pass working rolls - U mm. Hence, the degree of deformation without crimping with rollers is 1.5. The height of the brook is the height of the deformation - 1.05. The roller compression on both sides of the roll, necessary to ensure the degree of deformation along the ridge 1.1, is 8 mm. The average compression rollers - 4 mm. The loads that occur on the rollers as a result of the deformation do not exceed 3-5% of the loads on the work rolls. Claim 1. Method of rolling billet billet, including rolling the slab into several threads joined together and their subsequent separation, characterized in that, in order to increase the durability of the work rolls by reducing the wear of the separating ridges of the rolls and improving the quality of the blanks in the separation zones , between passes, the zones of future separation of workpieces are locally deformed, and the degree of local deformation is chosen so that, in the next passage, in the areas of separation of workpieces, it does not exceed 10%. 2. A method according to claim I, characterized in that the width of the local deformation zones is chosen to be (0.04-0.25) C, where C is the step between the strands along the ridges of the work rolls. Sources of information taken into account in the examination 1. UK patent number 1040119, cl. In 2dr / 1964. 2. USSR author's certificate number 527218, cl. B 21 B 1/03, 1975. 3.Vorontsov NM and others. Operation of rolls crimp and varietal mill. M., Metallurgists, 1973, fig. 42