SU1439870A1 - Method of electron-beam welding of rotor structures - Google Patents

Description

The invention relates to electron beam welding, in particular, to a technology for welding rotors of a hot engine path and can be used in engine building, turbine building and aggregate building.

The purpose of the invention is improving the quality of welding of finished parts by eliminating craters at the beginning and end of the seam.

Figure 1 shows the assembly diagram for electron beam welding of the rotor (axial section): figure 2 is the same, top view.

The method consists in installing at the beginning and end of the joint 1 technological input and output liners 2, which are applied to the joint 1 and pressed against the end surfaces of the parts of the blade 3. For this, the sector parts of the blade 3 are assembled on an annular snap in the form of supporting rings 4 and 5 located on the ends of a bandage mounted from parts. In rings 4 and 5 of the tooling, on their inner surfaces facing the end surfaces of the parts, grooves 6 are preliminarily performed on the entire thickness of the rings, placing them with a step equal to the distance between the straight joints 1 of the parts. blades 3. In the grooves 6 of the rings 4 and 5 insert the technological liners 2 with shoulders 7 having predetermined geometric parameters. Rectilinear joints 1 in the design of the rotor of the hot engine tract are located at an angle a relative to the axis of the product. Moreover, the larger the angle a, the more severe the deterioration of the conditions of heat removal from the edge sections of straight joints to less heated areas of the welded assembly. It was established experimentally that with an increase in the angle of inclination, the length of the crater at the beginning and end of the seam increases. Therefore, the beads 7 are placed on the edge sections of the joints 1 at an angle of inclination a to the axis of the product and are made together with the inserts 2. The width a of the beads 7 E1 is chosen equal to the width of the seam in its upper part when welding butt 1. This is due to the fact that in case of an increase in width the flange is observed its incomplete melting, which leads to the need to remove excess metal by additional machining, i.e. to increase the complexity of manufacturing structures. In the case of reducing the width of the shoulder at the edge sections of the seam, defects such as undercuts arise, which must subsequently be corrected, which also leads to an increase in labor intensity. The height of the shoulders h is determined by e depending on the thickness of the welded parts at the edge sections of the joints 1, since the size of the crater depends on this. It was experimentally established that the height of the beads is 1 / 10-1 / 15 of the thickness of the part, which guarantees filling the volume of the crater with molten bead liquid metal. Reducing the lower limit on the height of the bead may lead to insufficient filling of the volume of the welding crater. An increase in the upper limit along the height of the shoulder leads to the formation of large sagging at the end sections of the welds formed due to the excess volume of molten metal of the shoulder.

The length of the flanges is chosen equal to the length of the crater, based on the condition of full filling of the crater with the volume of the flange metal. Based on statistical data, the empirical dependence of the bath length on the angle a of the inclination of the joints 1 to the axis of rotation of the product is determined.

L-.5 + 3 sin a, where L is the flange length equal to the length of the crater; and - the angle of inclination of the joint to the axis of the product.

Some average flange sizes are shown for each part size in the table.

The thickness of the flange, equal to 1 / 10-1 / 15 of the thickness of the joint, provides, along with its other geometric parameters, defect-free formation of seams at the edge sections. When the flange thickness is more than 1/10 of the welded thickness (1/9, 1/8 ...) at the marginal sections of the welds due to the excess of molten metal, sagging are formed, requiring additional machining, i.e. increases the complexity of manufacturing parts. When the flange thickness is less than 1/15 of the welded thickness, an underestimation of the seam is formed in these areas, which is also unacceptable and requires welding of the seams.

The liner 2 with shoulders 7 have different sizes due to the different thicknesses of the details of the blade 3 in the edge sections of the joints 1. Install the liners 2 in the grooves 6 of the rings 4 and

5. The rings are pulled together between each other in the center of the product and with the help of screws 8, the liners 2 are tightly pressed against the end surfaces of the annular joint. In this case, the collars are placed along the joints 1. The assembled product with snap is placed in the chamber.

The fixation of the details of the blades 3 relative to each other is carried out by tacking straight lines of the electron beam

1. The length of the tack zone is located in the middle of the joints 1 to exclude vodka in the contact areas of parts with equipment. Welding of the longitudinal joints 1 begin and end on the inserts 2, after which the rings are removed and the inserts are cut.

An example implementation of the method. We performed electron beam welding of the rotor design of the compressor impeller, consisting of 35 separate blades, from VT25U titanium alloy. The maximum weldable thickness of the blades 10 was 42 mm, and on the contact side of the supporting rings - 15 mm and 37 mm. Assembly implementation on supporting rings of the same material. The height of the rings was 50 mm, and the thickness corresponded to 15 the thicknesses of the ends of the rim, i.e. 15 mm and 37 mm. In the supporting rings, grooves for the entire thickness of the rings were preliminarily performed before assembly. The width of the groove was 20 mm and the length was 30 mm. The blades were assembled in a rim on the supporting rings so that the ends of the straight joints were opposite the grooves. Technological inserts were inserted into the grooves, fixed to the end surfaces of the 25 blades, providing a snug fit. The liners were 15 mm and 37 mm high, and 15 mm wide. length - 25 mm. The beads on the respective inserts were made: 30 wide: a - 3 mm high: Ή1 - 22 mm, Ng - 4 mm long: L - (5 + 3 sin a) = (5 + 3 0.82) = 7.5 mm angle of inclination a “55 °. 35

The liners were installed with the collars at the junction of the parts and pressed them tightly to the end surfaces of the parts with a gap of not more than 0.2 mm.

Top produced on the installation of ELU20, equipped with a power unit BEP-60 / 15K. Previously, the joints were seized by an electron beam in the middle of their length.

Tack modes: accelerating voltage 60 kV beam current 45 mA focus lens current 460 mA welding speed 30 m / h

Welding was started and finished on the liners and carried out at the same speed and accelerating voltage, but with a beam current of 75-160 mA, depending on the thickness of the parts.

After welding, all straight seams have the same reinforcement height and a root bead uniform in height.

The spread of the blades relative to each other is within the requirements of the drawing for the manufacture of this product.

Compared with the base object, for which the prototype is adopted, the proposed method will allow to obtain minimal deformation from the thermal effect of the beam on the welded parts. The possibility of self-installation (melting) of the liners eliminates the occurrence of stress at the edge sections of straight joints and thereby eliminates the likelihood of cracks in the joint and the base metal of the blades.

(56) USSR Copyright Certificate No. 976573, cl. B 23K 15/00, 1981.

Swedish patent No. 371384, cl. B 23K 15 / 00,18.11.74.

The influence of the standard sizes of technological beads on the quality of the weld metal

Metal thickness mm The angle of inclination of the joint to the axis of rotation of the part, ⁰ Geometrical parameters of the crater Flange length - (5 + 3 sin a) mm Flange height Seam quality Note length, mm width on the. mm volume, mm ³ estimated mm taken in fractions of the thickness of the metal fifteen 0 20 4.65 5,6 16 16.4 25.5 5.0 6.0 1,1 1.4 1/15 1/10 No defect

Table continuation

Tol shina Tilt angle Geometrical parameters of the crater Flange length Flange height Seam quality Note metal la mm at the joint to the axis of rotation of the part, ⁰ length, mm width on mm volume, mm ³ - (5 + 3 sin a) mm estimated mm taken in fractions of the thickness of the metal 45 6.7 31.5 7.1 1,5 1/10 Defek Geometrical * no sky 70 7.5 35.1 7.8 1.5 1/10 meters 70 7.5 35.1 7.8 17 1/9 Nally - craters you taken metal Redenny- 0 4.8 28.1 5,0 1.9 1/15 · " mi from 20 5.7 33.8 6.0 1.9 1/15 processing thirty 45 6.8 41.8 7.1 2.0 1/15 N results 70 7.6 48.6 7.8 2.1 1/14 AND 8 exp 70 7.6 48.6 7.8 1.8 1/16 Sub- recommendations PS for each 0 4.9 42.9 5,0 2.6 1/15 W thickness 20 5.7 53.5 6.0 2.7 1/15 40 45 6.8 70.1 7.1 3.0 1/13 W 70 7.7 82.0 7.8 2,8 1/14 and 70 7.7 82.0 7.8 2.5 1/16 AND

Claims (1)

The invention is a METHOD OF ELECTRON BEAM WELDING OF ROTOR STRUCTURES, in which sector parts of the blades are joined together in a ring tool before welding and welding parts with full penetration of the joint, starting and ending seams on the ring tool, characterized in that. that, in order to improve the quality of welding of finished parts by eliminating craters at the beginning and end of the weld, grooves are made in the ring rigging along the inner surfaces of the interface with sector parts to the entire depth with a step equal to the distance between the joints, and set in the grooves before welding input and output inserts that overlap the joint and press them to the end surfaces of the parts, while the length of the liners L is chosen equal to 'L = 5 + 3 slna i 5 + 3sina, where a is the angle of inclination of the joint to the axis of the product. 1439070 Editor N. Kozlova Compiled by V. Morochko Tehred M. Morgenthal Corrector M. Keretsman Order 3351 Circulation Subscribed NGO Search for Rospatent 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Combine Patent, Uzhgorod, 101 Gagarin St.