RU1770014C - Method of disk uncoiling (reeling out) - Google Patents

Abstract

The invention relates to the processing of metals by pressure and can be used in the manufacture of products such as disks of gas turbine engines from heat resistant nickel alloys. The method of processing heat-resistant nickel-based alloys consists in heating to a temperature of 1000-1100 ° C, deformations by rolling under conditions of superplasticity of the disk material in the direction from the workpiece axis to the periphery of the drive cantilever rollers inclined diametrically opposite to the axis of the workpiece, and the pairs of rolling rollers are offset relative to the horizontal plane passing through the rolling axis by an amount equal to half the diameter of the rolling roller, whereby the mutual rotation speeds of the rollers are set with a mismatch of 3-6% relative to the workpiece and 6-12% relative to each other. The method allows to obtain the following disk properties: c% 147-150 kg / mm2; OQI-- 97-101 kg / mm2: (5 21-27%. 1 tab.

Description

The invention relates to the processing of metals by pressure and can be used in the manufacture of products such as disks of gas turbine engines (GTE).

There is a known method of rolling discs, in which the workpiece is rotated and rolled under conditions of superplasticity of its material in the direction from the axis of rolling by drive cantilever pairs in pairs diametrically opposite to the axis of rolling rollers (1). Since GTD disks operate at high temperatures, high pressure, they must have high service properties. However, the aforementioned method does not provide the necessary level of service properties of the product, and also has a significant drawback - high specific rolling forces.

The closest in technical essence and the achieved effect to the proposed solution is the rolling method chosen by the authors for the prototype, which differs from the above in that the pairs of rolled cantilever rollers are offset from the horizontal plane passing through the rolling axis by an amount equal to 0.1 ... 0.5 the average radius of the neutral cross section of the rollers. Due to this, a reduction in the specific rolling forces is achieved, however, the service properties are not significantly improved.

The aim of the present invention is to improve the mechanical and service properties of the disks of gas turbine engines made of heat resistant nigel-based alloys.

The preform is heated to 1000-1100 ° C and deformed by rolling under conditions

sl

h o

Јь

superplasticity of the material of the disk in the direction from the axis of the workpiece to the periphery of the drive cantilever rollers inclined to the plane of the disk, pairwise diametrically opposed to the axis of the workpiece, and the pairs of rolling rollers are offset from the horizontal plane passing through the axis of rolling by an amount equal to half the diameter of the rolling roller, moreover, the mutual speeds of rotation of the rollers are set with a mismatch of 3-6% relative to the workpiece and 6-12% relative to each other.

Rolling the workpieces by rollers displaced relative to the horizontal plane, rotating with a mismatch of speeds, led to the formation of a radial metallophysical texture of the metal and a turbulent twist of the fibers in the direction of rotation of the workpiece. Since the workpiece is rotated around the horizontal axis of rolling, this prevents warping of the rolled workpiece. Due to the displacement of the rollers with respect to the horizontal plane passing through the rolling axis, no metal build-up occurs in front of the rollers. When rolling by the proposed method, an increase in shear stresses occurs in the deformation zone. Due to the release of the γ phase, carbide forming elements grow, while the carbon content remains the same as before. Carbides have a favorable effect on the tensile strength at high temperatures and affect the chemical stability of the matrix. Along with the increase in carbides of the Me.S. MebS type, the volume fraction of carbides of the Me2zCe type decreases. The volume fraction of grain slippage in the deformation zone increases, as a result of which the slipping along grain boundaries increases, which in turn reduces the strain forces. In addition to carbides, an excess 1-phase is also formed. which envelops them and the grain boundary with a plastic and creep resistant layer. Rolling of blanks of disks with cantilever drive cantilever rollers arranged in pairs diametrically opposed to the axis of the workpiece, the pairs of rolling rollers being displaced relative to the horizontal plane passing through the axis of rolling by an amount equal to half the diameter of the rolling roller, the mutual rotation speeds of which are set with a mismatch of 3-6% relative to each other, provides an increase in the mechanical properties of the disks.

The authors of the patent and scientific and technical literature, the set of distinctive features is not known.

The preheated billet is rotated and rolled under conditions of superplasticity of its material in the direction from the rolling axis inclined to the plane

0 rolling drive cantilever rollers, pairwise located diametrically opposed to the axis of rolling. The billet is rolled simultaneously by both pairs of rollers located at the same distance r from the rolling axis. During the rolling process, the billet is rotated around the horizontal axis of rolling, in addition, to prevent the influx of metal in front of the rollers, the rolling 0 is taken by rollers displaced relative to the horizontal plane passing through the rolling axis in the direction opposite to the direction of rotation of the billet by a value of D equal to half 5 not the diameter of the rolled video clip. During the rolling process, the workpiece is rotated at a speed of V. The rotation of the rollers is set with a mismatch of speeds. The speed of the 1st pair of rollers can be written as:

0Vi V + (3-6)% V

V2 V- (3-6)% V

The proposed method was carried out at the SRD-800 mill.

As a material for research

5 used a heat-resistant alloy based on nickel - EP742U.

After preliminary heterozygous annealing from the single-phase region, as well as precipitation under quasi-isothermal conditions

0 on the press with a force of 1600 i.e. from cylindrical blanks D 200 and Н 260 mm, blanks were obtained for rolling d. with an ultrafine-grained micro-duplex structure with an average size of dy 1 .. After

5 washer deposits are rolled out under superplasticity conditions. For workpieces made of heat-resistant nickel alloys (EP742U), the deformation temperature was 1000 ... 1100 ° С at the strain rate ....

0 A feature of the proposed rolling method is a reduction in the spot of contact and the resulting reduction in slippage, as well as a reduction in the rolling force. As a result of the experiment, the mechanical properties of the product were improved. The mismatch value (3 6%) was obtained practically and the optimal value was established

mismatch of 4%, at which the mechanical properties are the highest, this can be seen from the graph and the table.

The displacement of the axis of the roller relative to the horizontal plane passing through the rolling axis Ah is equal to half the diameter of the rollers. The optimal distance Д h is also practically determined.

The proposed method for rolling discs of gas turbine engines is economical since the weight of the article is reduced from 52 to 42 kg. whereby the metal consumption is reduced from 52205 kg (per 1000 pcs.) to 42000 kg. Costs for metal decreased from 1305125 rubles to 1044100 rubles. A decrease in the mass of the disk leads to a decrease in the mass of the engine, which in turn facilitates the entire structure of the aircraft, and also reduces the fuel consumption of the engine. This method is less energy-intensive, since the equipment used for manufacturing has less effort. Reduced deformation forces increase tool life.

Claims (1)

SUMMARY OF THE INVENTION A method for rolling disks, primarily their heat-resistant nickel alloys, including rolling under superplastic conditions in the direction from the axis of the workpiece to the periphery of the drive cantilever rollers inclined to the disk plane, pairwise diametrically opposed to the axis of the workpiece, the pairs of rolling rollers being offset relative to the horizontal plane passing through the axis of rolling by an amount equal to half the diameter of the rolling roller, characterized in that, in order to increase mechanical properties, the mutual speeds of rotation of the rollers are set with a mismatch of 3-6% relative to the workpiece and 6-12% relative to each other.