SU1766564A1 - Method of ring production - Google Patents

Abstract

Use: in the production of specialized rings on rolling mills. SUMMARY OF THE INVENTION: The heated billet is precipitated, while the billet is heated unevenly in height to the limit ah of the deformation temperature range. Stitch the workpiece with a punch to obtain a blind hole from the side of the less heated end to a hole depth equal to 0.84-0.94 of the height of the workpiece after the draft. Thus, before rolling at a hollow semi-finished product, the diameter of the less heated end is small enough, and the more heated one is large enough and shifted to the center of the semi-finished product due to the bulging of this end during the firmware. The profile of the side surface of the semifinished product is closer in shape to the profile of the rings with a central annular ledge at their outer diameter, which leads to a reduction in the time of rolling. 1 tab., 3 Il.

Description

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The invention relates to the field of metal forming, in particular, to the manufacture of rings with a profile surface.

There is a known method of manufacturing ring products, in which the heated billet is precipitated, pushed up to obtain a blind hole, pierced to remove the web, and rolling the billet between the mandrel and outer roll through its thickness and along its height between tapered rollers.

The disadvantage of this method is the large labor intensity due to the following reasons: 1) low productivity, due to the long time of rolling rings with a profile in the form of an annular protrusion in the central part of their outer side surface; 2) a long time for heating and holding the preform before sludge to ensure uniform heating.

The purpose of the invention is to reduce the labor intensity of manufacture.

The goal is achieved in the method of manufacturing rings, mainly shaped, in which the heated billet is slumped, pierced with a punch to form a blind hole, the piercer is removed by punching and rolling the billet between the mandrel and the outer roller through its thickness and its height between the conical rolls, which, according to the invention, the workpiece is heated unevenly in height within the temperature range of the deformation, and the piercing is carried out from the side of the less heated end surface and to a depth of Well holes equal to the height of 0.84 ... 0.92 preform after rainfall.

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Fig, 1 shows the contour of an upset billet with a less heated upper end surface; in fig. 2 - the workpiece after flashing the blind hole; in fig. 3 - the initial stage of rolling and the section of the profile ring.

The method is carried out as follows. The original billet is placed in a furnace and unevenly heated so. so that the lower and upper parts of it have a temperature equal to the lower and upper limit of the temperature range of deformation of the metal used. Then, the workpiece 1 is placed on the press table and upset to the height H, which determines the most optimal dimensions of the semi-finished product for subsequent piercing and rolling. At the same time, less heated areas are deformed to a lesser extent (Fig. 1, the upper part of the workpiece), and the settled workpiece has different diameters of the end planes DI, D2, as well as the maximum diameter of the barrel Dmax offset to the more heated end plane (Fig. 1, bottom). part of the workpiece). The deposited preform 1 is turned to a punch with a less heated end plane and a blind hole is pierced in it (Fig. 2). In this case, at the beginning of the piercing in the upper part of the workpiece, a hole is formed, the less heated metal is partially entrained by the punch into the blank, which decreases slightly in height and reduces the diameter DI of the less heated upper face plane to the value D. At the end of the firmware, the height of the workpiece increases significantly due to buckling of the lower end plane, the maximum diameter becomes the diameter D of the lower end plane, which is fixed at a distance I from the press table, and the resulting height of the workpiece 2 after the piercing exceeds the height of the deposited workpiece 1, i.e. ..In the firmware, a blind hole is formed with a depth S, equal to S (0.84 ... 0.92) H. In this case, there is the greatest buckling of the lower end plane of the workpiece, i.e. Hmax (0.16 ... 0.20) Hi, whereas at a less deep blind hole l (0.08 ... 0.15) Hi. Next, the stitched workpiece 2 is moved to another position that has a through hole in the press table, is placed with a jumper 3 opposite the opening and the piercing 3 is removed by punching. As a result, in the operations of upsetting, piercing and punching, a hollow shaped semi-finished product 4 having the largest volume is formed. metal in the central part, defined by a diameter of 62, and the smallest mass

near the end planes defined by the diameters D and D.

After deforming on the press, the hollow semi-finished product 4 is reheated again in

furnaces and then fit onto the mandrel 5 of the rolling mill until it stops at the movable table 6. The mandrel 5 with the table 6 and the semifinished product 4 is brought closer to the outer profiled roller 7, simultaneously with the side opposite the roller 7, the conical rolls 8 are fed to the finished product 4, after which in the diametral plane they are crimped in height by the rolls 8 and in thickness by the roll 7 and mandrel 5 of the prefabricated 4 to form

5 of the profile ring 9 (Fig. 3).

Uneven heating of the billet allows redistributing the volume of the metal in the hollow semi-finished product 4, reducing it in areas adjacent to the less heated face plane, and increasing it in the central part of the semi-finished product, i.e., bringing it closer to the final ring 9 shape. on the side of the less heated end plane, it is also suspended by the ductility of the metal. The formation of a jumper 3 on the side of the less heated part of the workpiece is accompanied by cracking of the metal of the end zones adjacent to the jumper 3.

0 The depth of the hole, 84H does not contribute to the bulging of the end plane with a diameter of D2 and does not provide the required redistribution of metal from the end zones to the center, i.e. 1 (0.08 ... 0.15) N, which is not enough. In addition, the volume of jumper 3 being removed unnecessarily increases. If, 92 H, then the probability of metal cracking in areas adjacent to bridge 3 increases, moreover, all high firmware pressure values are required, i.e., a press of greater power and more resistant die material for punches, which is not economically justified.

Rolling hollow semi-finished product 4 with

5, in the form as close as possible to the shape of the profile ring, occurs in a shorter period and in one transition without fear of the formation of plugs and clamps during the formation of the annular protrusion on the ring. This provides an increase in the productivity of the method, i.e., a reduction in its labor intensity. In addition, uneven heating of the workpiece in height does not require its exposure in a furnace to equalize 5 temperature to height, which shortens the heating time and also reduces the complexity of the method.

Example. The product is a ring (see Fig. 3) of a titanium alloy PT-ZV with a height of 295 mm, an internal diameter of 1440 mm, an external diameter of 1635 mm with an annular protrusion of a pyramidal shape (the height of the pyramid is 28 mm, the size of the bases: larger - 220 mm, smaller - 140 mm). Experiments were carried out in the process of making an experimental batch of rings on a ring-rolling complex RAW 315/260 2000/4005 according to the modes of operation of the equipment specified from personal computers. Billets with dimensions of 0410 (1070 ... 1083) mm were placed on the butt in an annular furnace with a moving hearth and upper heating with gas burners. Heating temperature - 1000 ° C. The uneven temperature of the workpieces in height was provided by varying the time of their heating (the top of the workpiece was heated faster). The heated billets were placed on the hydraulic press table with a force of 40 MN, centered with a centering device, set off, then a blind hole with a diameter of 250 mm was pierced with a punch. Next, the workpiece was lifted with a centering device, the press table was moved under it, the workpiece was set to another position, the jumper was positioned above the hole in the press table, after which the wire hook was removed by punching punch. Then the hollow semi-finished product was placed in an oven with a temperature of 920 ° C, heated in current 40. „120 minutes, removed from the furnace, placed on a mandrel with a diameter of 240 mm of the roll mill, brought the mandrel together with an outer profiled roller, from the opposite side were brought to the semi-finished product usnye rolls and rolled the last height and thickness to the profile ring sizes. According to the initial sizes of the semi-finished product, the computer of the mill autonomously selected the smallest rolling technology in time. During the experiments, the heating temperature of parts of the workpiece was controlled, the coordinates of the end planes of the workpiece on the press, the depth of piercing of the blind hole, the height of the upset workpiece. The results of the experiments are presented in the table (experiments 1-10), from which it is clear that the prototype method (experiment 1) causes the greatest operational rolling time, cooling the workpiece below the deformation temperature range (experiment 5) leads to the destruction of the workpiece during the draft, too deep a hole during the firmware, as well as the location of the less heated end plane of the workpiece on the press table leads to the destruction of the workpiece during the firmware. A reduction in rolling time of 1.4 ... 1.6 times is achieved in experiments 4, 7-9, carried out in full accordance with the invention. Note that heating

blanks above 1000 ° C were not used, as it did not provide the required properties in the alloy.

The product is a steel ring 40X with a central annular ledge on the outer

a diameter of 30 mm and a base length of 50 mm. Ring size - f 100 mm. Billets 200 (547 ... 550) mm were heated to 1200 ° C, precipitated to 132 mm in height, a blind hole with a depth of 100 (prototype) and 115 mm (, 87) were pierced, the jumper was removed and rolled without heating on the mill time 28 s. When the preform according to the invention was heated from one end plane to 1200 ° C, on the other to 1040 ° C, was installed before flashing with a less heated end plane opposite the punch, a hollow semi-finished product was obtained, which was rolled into a ring in 18c.

With uneven heating of the billet of titanium alloy PT-ZV were in the furnace for 0.5 h, and the billet of steel 40X - 0.8 h less than with uniform heating.

Claims (1)

Invention Formula A method of manufacturing rings, preferably shaped, in which the heated billet is precipitated, pierced with a punch to obtain a blind hole, the punching bridge is removed and the billet is rolled between the mandrel and the outer roller through its thickness and height between the conical rolls, characterized in that reduce the labor intensity of manufacturing, the workpiece is heated unevenly in height within the temperature range of the deformation, and the piercing is carried out from the side of the less heated end surface and to the depth holes, equal to 0.84-0.92 height of the workpiece after precipitation. 1 I, 2) / Editor 9bi.B Compiled by A. Anishchenko Tehred M. Morgenthal Proofreader S.Pekar