RU2042466C1 - Shaft forging method - Google Patents

Abstract

FIELD: forging equipment. SUBSTANCE: method of forging shafts includes steps of heating an ingot, upsetting it an broaching, upon deformation process providing a displacement of an inner central zone of the ingot onto its surface. In order to perform that, the upset ingot is being broached and expanded along its diameter, and cone cylindrical broaching tools are being alternatively embedded into an opening, had been made. Each subsequent tool has a diameter of its cylindrical portion more, than a previous one. A ring, had been made, is being chopped to separate parts, then being straightened for forging a shaft from each part. The axial defect zone, had been displaced onto the surface, is being partially removed with the scale at subsequent heating operations, and it is being completely removed upon working of the shaft forging. In the result a quality of the metal, had been remained, is significantly enhanced, as the axial zone contains a large number of additives. The expansion of the broached blank along its diameter enhances structure of metal in the whole body of the forging, providing extremely high mechanical properties of shafts metal. After chopping the ring forging to separate parts, blanks for forging shafts are being made. EFFECT: enhanced quality of shafts. 1 cl, 9 dwg

Description

 The invention relates to the processing of metals by pressure and can be used for forging shafts of various metals and alloys.

A known method of manufacturing forgings of shafts, including heating the ingot, billing, draft and broaching, moreover, the ingot upset is combined with extrusion of a faulty defective zone into the hole of a concave spherical sedimentary plate [1]
This method of manufacturing forgings of shafts in the body of the ingot from the profitable side creates conditions of uneven comprehensive compression, contributing to the study of the metal structure, brewing of internal defects. However, the axial defective zone of the ingot is not completely squeezed out, and the used methods of forging the precipitate and broaching do not provide uniform development of the metal structure throughout the forging volume. And, as a result, they obtain low, uneven cross-sectional mechanical properties of the forgings.

 There is a known method of forging shafts [2] according to which the ingot is cut into two equal parts along the longitudinal axis of symmetry, each workpiece is crimped along the separation plane with a height-strain factor of 1.3-1.6 with the molding of a T-profile, the protrusion of which has a width of 1,0-1,2 width of the segregation zone of the ingot, and the protrusion is separated from the T-profile. The disadvantage of this method is the insignificant study of the metal structure in the entire forging volume, which negatively affects the mechanical properties of the resulting shafts.

 The technical result obtained by using the invention lies in the possibility of manufacturing shafts of high-quality metal with high mechanical properties throughout the forging volume.

 The purpose of the invention is the creation of a method of forging shafts, in which the central zone of the ingot is brought to the surface and during deformation, along with draft and broaching, the workpiece is distributed in diameter.

 The goal is achieved by the fact that in the method of forging the shafts, including heating the ingot, cutting it into pieces with the output of the central zone to the surface and forging from each part of the shaft, according to the invention, the ingot is deposited before being cut, stitched and repeatedly distributed in diameter by alternately introducing into the obtained the hole of cylindrical piercing with a conical section and draft of the workpiece with embedded piercing, with each subsequent piercing the diameter of the cylindrical part is larger than the previous one, and after cutting the resulting ring Eve forgings are straightened to pieces.

 A large amount of impurities accumulates in the axial zone of the ingot. When flashing a deposited ingot, part of the axial defective zone is removed. Subsequently, after the central zone of the ingot is brought out onto the forgings surface, part of the defective zone goes into scale during subsequent heating, and finally it is removed by machining the shaft forgings. Thus, the quality of the metal of the finished shaft increases sharply compared to the quality of the ingot metal. Distribution of the stitched billet in diameter improves the study of the metal structure in the entire forging volume, which leads to a sharp improvement in mechanical properties. As a result of cutting the annular forgings into parts, blanks for forging the shafts are obtained.

 Figure 1 presents the precipitated ingot; figure 2 precipitated ingot with a stitched hole; figure 3 the beginning of the introduction into the deposited ingot with a stitched hole of the first conical-cylindrical piercing; figure 4 intermediate forging with a fully embedded conical-cylindrical piercing; in Fig.5 intermediate forging obtained by sludge together with a conical-cylindrical piercing embedded in it; Fig.6 the beginning of the introduction into the intermediate annular forging of the next conical-cylindrical piercing; 7, the final forging of the ring; on Fig forgings rings chopped into parts; Fig.9 final forging of the shaft.

 The method of forging shafts is implemented as follows.

 The ingot is heated to forging temperature, fed to deforming equipment and precipitated. In the deposited ingot 1 (FIG. 1), a hole is stitched and a precipitated ingot with an opening 2 is obtained (FIG. 2). A conical-cylindrical piercing 3 is inserted into the obtained hole (Fig. 3). When introducing firmware, the deposited ingot is distributed in diameter. Get an intermediate forging with a fully embedded conical-cylindrical piercing 4 (figure 4), which is upset with the embedded piercing. An intermediate forging 5 is obtained (FIG. 5), from which the conical-cylindrical piercing 3 is removed (FIG. 5). Get an intermediate annular forging 6 (Fig.6).

Then, another conical-cylindrical piercing 7 (FIG. 6) is introduced into the obtained intermediate annular forging 6 (FIG. 6), the diameter of the cylindrical part of which D _{2 is} larger than the diameter of the cylindrical part D _{1 of the} previous conical-cylindrical piercing. Next, the cycle is repeated several times. If necessary, the intermediate ring forgings are heated to forging temperature. The result is the final forging of the ring 8 (Fig.7), which is cut into several parts, for example, into two 9 and 10 (Fig.8). Then the resulting half rings are straightened and each is pulled onto a shaft of the required size and shape. Get the final forging of the shaft 11 (Fig.9).

 PRI me R. An ingot was made of steel 40X GOST 4543-71 with a diameter of 100 mm and a height of 200 mm. Four stitchings were made: one conical with a cylindrical girdle with a diameter of 30 mm and three continuous conical-cylindrical with a diameter of the cylindrical part, respectively: 45 mm, 70 mm and 100 mm. Material piercing steel 5XHM.

The ingot was heated to 1250 ^{° C} in an electric furnace. Heating was controlled by a platinum-platinum-rhodium-thermocouple and a KVP1-503 device.

Forging was performed on the hammer with falling weight parts of 1 m. Pins hammer and pierce previously warmed to a temperature of 200-250 ° ^C.

The heated ingot was mounted on the lower hammer and, with the blows of the upper hammer hammer, besieged it to a height of 100 mm. A precipitated ingot 1 was obtained (Fig. 1), in which a hole with a diameter of 30 mm was pierced along the axis. Got a precipitated ingot with a hole 2 (figure 2). A conical-cylindrical piercing 3 (Fig. 3) with a diameter of the cylindrical part of 45 mm was introduced into the obtained hole with a diameter of 30 mm. When introducing the piercing, the deposited ingot was distributed in diameter and the defective zone was worked out. Received an intermediate forging with a fully embedded conical-cylindrical piercing 4 (Fig. 4), which was besieged with the embedded piercing to a height of 80 mm. Received an intermediate forging 5 (Fig. 5), from which the conical-cylindrical piercing 3 was removed (Fig. 5). Received an intermediate ring forging 6 (6) with dimensions: outer diameter 145 mm, inner 45 mm, height 80 mm, which was heated to 1250 ^about C.

 Then, a second conical-cylindrical piercing 7 (Fig. 6), the diameter of the cylindrical part of which is 70 mm, was introduced into the obtained intermediate ring forging 6 (Fig. 6). After the full implementation of the conical-cylindrical piercing, the obtained intermediate forging was besieged to a height of 60 mm and the piercing was removed. An intermediate ring forging was obtained with dimensions: outer diameter 160 mm, inner 70 mm, height 60 mm.

 Then, a third conical-cylindrical piercing with a cylindrical diameter of 100 mm was introduced into the intermediate forging hole, after which the intermediate forging was besieged to a height of 40 mm and the piercing was removed. Received the final forging of ring 8 (Fig.7) with dimensions: outer diameter 190 mm, inner 100 mm, height 40 mm

The resulting final forging ring was warmed to 1250 ^C and hacked into two parts 9 and 10 (Figure 8). Then the obtained parts were straightened and each was extended to a shaft with a diameter of 40 mm. Got two final forgings of the shaft 11 (Fig.9) with a diameter of 40 mm, length 220 mm

The forgings of the shafts are oil hardened. Quenching temperature of 800 ^{° C,} tempering 500 ° ^C. Laboratory trials of standard samples showed the following mechanical properties: σ _t = 1950 MPa, σ _to 2670 MPa, δ 17% Ψ = 68% KCU 73 J / cm ^2.

 The analysis of the macrostructure revealed a uniform fine-grained structure throughout the volume of the metal forgings.

 Using the invention will allow to obtain high technical and economic results.

Claims (1)

 METHOD FOR FORGING SHAFTS, including heating the ingot, cutting it into pieces with a central zone leading to the surface and forging from each part of the shaft, characterized in that the ingot is deposited before flashing, stitched and repeatedly distributed in diameter by alternately introducing cylindrical piercing with conical section and draft blanks with embedded piercing, with each subsequent piercing, the diameter of the cylindrical part is larger than the previous one, and after cutting the resulting ring forging into parts of their straightening lure.

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