SU1660815A1 - Method of manufacturing ringlike items - Google Patents

Abstract

The invention relates to the processing of metals by pressure, in particular to the production of ring products. The purpose of the invention is to improve the quality of the macrostructure of ring blanks and increase the utilization rate of the metal. The ingot is divided into sets of N * 981 blanks. The complete blank is cut into multiple parts. In this case, the ratio of the diameter of the complete blank left when cutting the neck to the diameter of the piercing mandrel is selected within D _w / D _o = 0.8 - 1.05, and the neck width is within 0.01 - 0.04 diameter of the complete workpiece. Next, cut the complete billet is heated to the temperature of deformation, after which it is stitched by the method of cross-helical rolling with simultaneous separation into individual ring blanks. The resulting blanks rolled on ring-rolling mill. The method allows, by improving the macrostructure, to reduce scrap by 20%, as well as to increase the utilization rate of metals by eliminating the squeeze when flashing blanks. 4 silt, 1 tab.

Description

The invention relates to the processing of metals by pressure and can be used in the manufacture of solid-rolled ring products such as crowns, flanges, bearing rings, power rings for aircraft engineering and other industries.

The purpose of the invention is to improve the quality of the macrostructure of ring blanks and increase the utilization rate of the metal.

FIG. 1 shows the original complete blank length L and diameter D; Fig, 2 - the workpiece after trimming into multiple blanks; in fig. 3 - flashing of the trimmed billet on the cross-helical rolling mill; in fig. 4 - rolling

ring blanks on a ring rolling mill.

The essence of the method is as follows.

The original complete blank (Fig. 1) of length L and diameter D is cut into multiple parts (Fig. 2, pos. 1) of length L. Trimming is based on the ratio of the diameter of the left neck (Osh) to the diameter of the piercing mandrel (D0) Osh / 00 0.8-1.05, i.e. Osh (0.8 ... 1.05) D0. The value of the coefficients of 0.8-1.05% is chosen depending on the diameter of the original complete blank (D) according to the table. At the same time, the neck width (S) is prescribed in the range of 0.01-0.04 of the diameter of the complete blank, i.e. S (0.01-0.04) 0.

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In this case, the cutting and cutting of complete blanks are carried out in combination with the use of the entire useful line (taking into account the constant minimum cut-offs), i.e. Complete blanks are cut into various weight weights of individual blanks, from which rings of a different assortment are made. Then, the trimmed complete workpiece 1 (Fig. 2) is heated to the deformation temperature (1050-1280 ° C depending on the steel grade) and transferred to the helical rolling mill, where during the squeezing process between the rolls 2, the mandrel 3 is pierced (FIG. .3), with a diameter of D0. In the process of flashing, the complex blank is divided into individual ring blanks 4 (FIG. 3) with a given outer diameter He, inner diameter DB and height N.

In the future, the ring blanks 4 (fig.Z) can be used as finished products or subjected to further redistribution, for example, rolling on a ring rolling mill (FIG. 4), where by simultaneous deformation between the outer 5 and inner 6 rollers, as well as between the end rolls 7 get the final annular billet 8.

The upper and lower limits in the ratio of the diameters of the neck (Osh) of the cropped workpiece and the piercing mandrel (D0) are selected on the basis of experimental data. It has been established that at a ratio of Osh / 00 0.8, there are cases of neck breakage and in the initial stage of insertion of the mandrel into the body of the workpiece, which violates the stability of the firmware process and leads to a distortion of the product profile. With a ratio of Osh / 0 to 1.05, metal flows are occurring on the end surfaces of the individual blanks, and the risk of separation of one blank from another increases.

Recommended optimal ratios of Osh / 00 depending on the diameter of the complete blank are given in the table.

Experiments to determine the range of the trim width are repeated under industrial conditions using model 18A65 cutting machines, as well as by fire trimming. The trimming on the machines is carried out with incisors of a width of 10, 15, 20, 25, 30 mm, and with fire cutting, the cutting width is 3-7 mm.

With the outer diameters of the complete blanks 300, 380, 450 and 500 mm, the undercut width is 0.01-0.1 of the diameter of 300 mm, 0.008-0.08 of the diameter of 380 mm,

0.007-0.07 diameter of 450 mm, 0.006-0.06 diameter of 500 mm.

When the neck width is less than 0.01 the diameter of the complete workpiece, the cutting conditions deteriorate sharply, which is reflected in the quality of the end surfaces of the workpiece (especially when cutting fire), and as the cutting width increases to more than 0.040, the complete workpiece breaks during firmware 0 due to deterioration conditions of capture of each subsequent cut workpiece.

When flashing the trimmed complete blanks on the covalent mills using this method, in 5 of the deformation process, the internal liquation zone of the blanks is evenly distributed on the inner surface of the sewn blanks, which positively reflects on the quality of transverse blanks 0 and the structure of the finished product.

The method also provides a significant reduction in the expenditure ratio of the metal due to the elimination of the squeeze when flashing each last billet. 5 Example 1. It is necessary to make ring blanks with an outer diameter of 352 mm, an internal diameter of 216 mm, height H 457 mm, weight 217 kg. To do this, use a complete round billet of steel grade 50 with a diameter of D 380 mm, a length of L 1600 mm and a weight of 1395 kg, which is cut into 6 billets with a length of L 254 mm (figure 2, pos.1).

From the given final size of the internal diameter of the ring blank 4, equal to DB 216 mm, the diameter of the pierced mandrel of the pier of the tube is chosen from technological considerations equal to Do 220 mm. According to the data of the table, based on the size of the outer diameter of the complete billet O 380 mm, the optimum ratio between the diameter of the Osh neck and the diameter of the pierced mandrel 00 should be Osh / 00 0.93. 5, Thus, trimming of the complete blank is carried out by a neck diameter equal to Osh 0.93 x Do 0.93 x 220 205 mm. The undercut is made by width S - 0.040 0.04 x 380 15 mm (Fig.2, pos . one). 0 After trimming, the complete blanks 1 are heated to 1230-1250 ° C are fed to the helical rolling mill, where they pierce between the rolls 2 on the mandrel 3 with the diameter Do 220 mm (FIG. 3). As a result of 5 firmware, six annular blanks 4 are obtained with an outer diameter of DH 352 mm, an internal diameter of DB 216 mm and a height of H 457 mm. The draw ratio here is 1.8. The expenditure ratio of the metal in the manufacture of these ring blanks is 1.07. Some of the ring blanks 4 are used as finished products, and some for subsequent processing, i.e. for the manufacture of ring blanks 8 with geometrical parameters DK dK x Hk 600 x 530 x 440. For this, the ring blanks 4 are individually transferred to a ring rolling mill (figure 4) where they are rolled by deformation in the radial direction between the outer 5 and the inner 6 rollers and in the axial direction, between the end rollers. Rolling is carried out to obtain the specified dimensions of the ring blank 8, i.e. up to DK x oV x Hk 600 x 530 x 440 mm.

Example 2 It is necessary to make ring blanks 4 with an outer diameter of DH 433 mm, an internal diameter of DB of 227 mm, a height of H 465 mm, and a mass of 388 kg. To do this, use a complete round billet of steel 50 with a diameter of D 450 mm, a length of L 2000 mm and a weight of 2470 kg, which is cut into 6 billets with a length of Li 321 mm. Based on the specified final size of the internal diameter of the ring blank 4, equal to DB 227 mm, the diameter of the piercing mandrel is chosen equal to Do 230 mm. According to the table, based on the size of the outer diameter of the complete workpiece D 450 mm, the optimum ratio of 0W / O0 should be in the range of 0.96-1.0, chosen equal to Dm / Do 0.99. Thus, in this case, the trimming of the complete blank is carried out by a neck diameter equal to ps 0.99 x x Do 0.99 x 230 228 mm. In this case, trimming is carried out on a width of S 0.04 D 0.01 x 450 x 4.5 mm (Fig. 2, pos. 1). In the following, analogies with the first example are used to heat and flash the trimmed complete blanks. The draw ratio for the firmware is 1.45. The metal consumption ratio for this case is 1.06. The result is an annular billet 4 with given geometrical parameters DH x DB x H 433 x 227 x 365 mm.

From ring blanks made according to the known and proposed method, samples were taken for the study of the macrostructure. In ring blanks, obtained by the method of single-piercing, in the internal layers of the cross section, segregation areas were found, which are sources of such defects as cracks, tears, etc. In the circular blanks manufactured by this method, the central part of the cross section had a dense homogeneous structure, and the axial zone of the initial billet, contaminated with liquids, was evenly distributed along the inner surface of the product within the machining allowance.

In the manufacture of ring blanks in a known manner, the scrap on the macrostructure of the metal of the finished rings (accumulation of non-metallic inclusions, friability, reduced hardness, delamination, etc.) is 2.15%. The manufacture of ring blanks by the proposed method will reduce the scrap by the indicated indicators by 20%, i.e. from 2.15% to 1.72%.

Claims (1)

Claims The method of manufacturing ring products, including cutting, trimming, dividing the ingot into sets of blanks connected by necks, heating to deformation temperature, piercing complete blanks and subsequent rolling, characterized in that, in order to improve the quality of the products and increase the utilization rate of the metal of the blank, The complete billet is pierced by the method of cross-helical rolling with simultaneous separation into separate ring blanks, while the ratio of the diameter is greater than ki Osh of the complete billet to the diameter of the piercing mandrel Do is determined from the Osh / Do range of 0.8 .., 1.05, and the ratio of the width S of the neck to the diameter D of the complete workpiece is from the S / D range of 0.01 .. 0.04 . s4 Ръ.З . R 8 6 Fi, GL