Way high-speed argon-arc welding of cylindrical parts

 

The invention relates to the manufacture and repair of machine parts, and in particular to methods for automatic arc welding of worn shafts, and can be used in mechanical engineering for application to the neck of the shafts of special alloys. The invention allows to obtain the deposited layers with a thickness of 0.2...0.5 mm without loss spray filler metal in the high performance area clean surface. The end of the additives previously formed into the shape of a cone with the angle at the vertex 2. Additive oriented relative to the workpiece at an angle= 75...88and injected into the contact generatrix of the cone additives and forming parts. Additive rotate, and the vector of linear speed of the base of the cone additives coincides in magnitude and direction with the vector of linear speed of the part. The surface is heated by the arc burning between a tungsten electrode and workpiece. The end of the additives is in the arcing zone and heats up this arc or from an external source to plastic state. Welding is carried out in such a geometrical arrangement of the elements that plane, perpendicular the DKI and electrode. 6 Il.

The invention relates to the manufacture and repair of machine parts, namely, the way automatic argon-arc welding of the workpiece surface, and can be used for repairing worn surfaces of cylindrical parts, as well as to give the surface details of the special physical and mechanical properties in their manufacture.

Most parts of internal combustion engines and transmissions modern agricultural machines have wear in the range 0,1...0,3 mm For repair of these parts are different methods of electric arc welding, which in real production conditions do not allow to obtain the thickness of the cladding is less than one mm on the side. During further machining needless weld metal irrational converted into chips. To conserve weld metal with subsequent machining is necessary to apply a layer thickness of 0.3...0.6 mm

There are various methods of welding, which consists in the fact that it surfaced parts and the electrode lead voltage. Arc burning between the part and the electrode melts plot surfaced workpiece surface and the electrode, which m is isoamsa and forms a deposited layer [Basics with car repairs. Ed. by Y. N. Petrov. -M.: Kolos, 1972, S. 220-265]. These methods give satisfactory welding results in obtaining the thickness of the surfacing 1,0...1,5 mm or more and if thermal effect of the deposition process does not adversely affect the properties of the part. However, in the manufacture and repair of parts often require the application of a layer thickness of several tenths of a mm, for example, when restoring a shaft journals under the bearings or by applying anti-corrosion coatings on parts like rods of hydraulic cylinders, etc.,

There is a method of welding, for example, in the environment of protective gases non-consumable electrode [Petrov, L., Tomarev A. S. Theory of welding processes. -M.: Higher school, 1977, S. 7, Fig.1.13 b) in which light arc between a nonconsumable electrode and the workpiece, and a filler wire serves in an arc or weld puddle formed on the details. The method gives the thickness of the surfacing of more than one mm, in addition, the process has a very low performance on surface area, surfaced in a unit of time (about 20...30 mm2/s).

The closest to the technical nature of the present method is a method of electric arc welding cylindrical parts [and.with. 599935. The way ele is tangent to the surface automatically fed electrode wire. Directly behind the combustion zone of the arc to the workpiece pressed with a little effort forming roller, the rotating friction of the item. Drops of metal, formed on the end of the electrode when the arc is on the roller and the latter is transferred to the surface of the part and formed by the roller into a thin layer. The method provides improved performance relative to counterparts, small heat-affected zone on the workpiece (about 0.3 mm) and satisfying the production of the thickness of the cladding is 0.5 mm

This method has the following disadvantages. Surfaced rollers are undercut (sharp transition surfaced roller to the surface of the part), which leads to the formation of a large number of pores and sinks in the fusion zone adjacent rollers. In the end there is a defect due to globular transfer of electrode metal electrode on the roller, and then on the item.

Another disadvantage of the process is the use of electrode wires of small diameter 0.5...0.9 mm, to ensure that the process must be submitted to the arc zone with high speed, about 1500 mm/sec High speed wire feeders require the creation of complex, inconvenient in operation mechanisms for wire feed.

However, to avoid these not the scarlet surface area of the electrode, located in the immediate vicinity of the details. So on used in the process of cladding modes (voltage, current, wire feed speed, and other), only globular transfer of electrode metal with regular short circuits by a drop of the interelectrode gap. Thus, when the welding wire with a diameter of 0.5 mm, the average diameter of the droplets of the metal electrode is 2.3 mm

This phenomenon can be eliminated by using wires of large diameter and decrease the angle of entry of the electrode into the arcing zone.

Secondly, the speed of rotation of the details, though, are higher than those used to prototype methods were insufficient and cause only globular metal transfer. On the other hand, such speed limit the performance of the deposition process, although its increase available reserves.

The aim of the invention is to increase the efficiency of the deposition process by ensuring the optimum thickness of surfacing and reduce spattering and burning metal while maintaining high productivity and high quality of the layer.

As is known, when using the prototype method to the surface rotating with the super guide on the surface of the rotating forming roller, installed directly behind the welding bath, and then the roller is transferred to the metal workpiece and form a deposited layer.

According to the invention, i.e. in the present method of surfacing, this objective is achieved in that the surface of the part is heated by an electric arc burning between a tungsten electrode and workpiece, and the end of the additives is formed into the shape of a cone with the angle at the vertex 2(Fig. 1), additive Orient the longitudinal axis relative to the axis of rotation of the workpiece at an angle= 75...88combining the generatrix of the cone forming additives with details and warm up the end of additives indirect impact of the arc or from the external power source to plastic state, and the vector of the peripheral speed of the base of the cone additives coincides with the direction and magnitude with the vector of the peripheral speed forming parts at the point of contact of the base of the cone forming additives with the details, and the line of action of the vectors of the peripheral speed of the additive and the details at the point of coincidence combine with the plane perpendicular to the axis of the piece and passing through the forming the tungsten electrode from the non-nuclear submarine is Noah argon-arc welding of cylindrical parts has new features: - the end of the filler wire is pre-formed into the shape of a cone with the angle at the vertex 2that is additive Orient the longitudinal axis relative to the axis of rotation of the workpiece at an angle= 75...88combining forming parts with the generatrix of the cone additives; - warm up the end of additives to plastic state; - the vector of the peripheral speed of the base of the cone and additives combine in magnitude and direction with the vector of the peripheral speed forming parts; - the line of action of the vectors of the peripheral speed of the additive and the details at the point of coincidence combine with the plane perpendicular to the axis of the piece and passing through the forming the tungsten electrode from the deposited layer.

In the analysis of patent and technical literature the applicant has not found another identical and equivalent to the proposed technical solution and therefore believes that the proposed invention meets the eligibility criterion of "novelty". In addition, the set of essential features and the achieved result is not explicitly follow from the prior art, which allows to make a conclusion on the conformity of the decision criterion "izobretatel trebuetsya figures 1, 2, 3, 4, 5, 6.

The first distinguishing feature of the invention is to make the end of the additives before the beginning of the deposition process forms a cone with the angle at the vertex 2. (Fig. 1).

After heating the surface by electric arc to a temperature close to the melting zone of the arc is served additive and in the moment of contact starts surfacing of the first roller. If the end of the additives is not cone shaped, such as to leave a flat end, in a moment of touch with additives detail (beginning welding) at a constant axial force F contacting the additive with the item will be geometrically point, that is, the specific pressure of the additive in place of the probe will be higher than if the contacts on the generatrix of a cone, hence the formation conditions of the first roll will be different, the roller is uneven in thickness than during stable running process, when the end of the additive is maintained automatically. Thus, when using this character provided the conditions for the formation of first surfaced roller, the same as in consistently reaching the deposition process.

The second distinguishing feature of surfacing is orientation additives longitudinal axis of atmosfair> and the combination of the generatrix of the cone forming additives with the details. When argon-arc welding of parts [Taratuta A. I., Crickets A. A. Progressive methods of repairing cars. Minsk: Uraji, 1986, S. 120] additive is typically placed at an angle to the workpiece surfaceless 45o. In the proposed method of welding this angle is closer to direct, but does not exceed 88o. Due to this characteristic ensures a minimum area of contact of the additive with the item and the minimum area of fusion of the filler metal with the base (near the point a, Fig. 1). When installed additives anglemore than 88ofor example 90o, contacting the additive with the item will occur on the median line of the face additives that will reduce approximately doubled at constant axial force F, the specific pressure additives on the item at the place of contact, and this affects the conditions of formation surfaced roller at the point A. in Addition, the metal additive can be smeared on the item to the left of point 0 (Fig. 1) still not on the heated surface, which degrades the quality of welding and fusion layer basis. A decrease in the angle to less than 75oquality is ome, with decreasing angleincreases the bending moment acting on the force F (Fig. 2 and 4), the additive on her departure L, which leads to increased wear of the mouthpiece, the beating of the end of additives and eventually deterioration of the conditions of formation of the roller at the point A.

The combination of a generatrix of the cone forming additives with details when contacting the additive with the item automatically when the axis additives intersects the axis of the items, and won't mix with it.

Thus, this provides optimal conditions for the formation of the platen, providing uniformity last in thickness.

The third distinctive feature of the method of welding parts is warming by the end of the additives to the temperature of the plastic state of the metal. The temperature of the additive on the departure L is gradually increased from the temperature of the mouthpiece at the output of the additive (about 100o(C) to the temperature of the plastic state of steel within 1000...1500oWhen the end of the additives still retains mechanical strength sufficient for transmission of axial force F. When the rotation of the additives in the place of its contact with the part under the influence of effort F is the plastic deformation of the metal end additives. Metal wit, the rich cap diameter larger than the diameter of the additive, and the edges of the cap are heated to the melting temperature of the metal.

Thus, this feature provides the movement of the metal additives in a certain place and in conjunction with other signs, the transition metal additives on the item at the point A.

Fourth, previously unknown characteristic of the invention is the coincidence of the direction and magnitude of the vector of the peripheral speed of the base of the cone additives(Fig. 3) and the vector of the peripheral speed forming partsat the point A.

The coincidence of vectorsandthe magnitude and direction of the following is achieved. Metal additives, extruded in the case base (pileus) and brought to melting, is held on a rotating insertion tool by surface tension. At point a (Fig. 3) molten metal additives in contact with the surface of the part heated by the arc to a state close to melting. Due to the coincidenceandat point a there is no relative displacement of microvolumes of metal additives and components that facilitates the transition micromanage argon gas, flowing from the nozzle argon-arc torch. The area of the sheet near the point And is a miniature of the welding bath, which is located in the zone of the electric arc (Fig. 3).

Thus, this feature provides uniform conditions of transition metal additives on the part of education microsurvey bath and, as a consequence, the formation of the deposited layer uniform in thickness.

The fifth distinctive feature of the invention is the combination of the lines of action of the circular velocity vectors additives and details at the point of coincidence with the plane perpendicular to the axis of the piece and passing through the forming napravlyayuschego electrode-side layer surfaced.

The significance of this characteristic is determined as follows. The zone of action of the arc on the workpiece surface has the shape of an ellipse, the major axis of which coincides with the direction of welding. The center of the ellipse 02(Fig. 3) is displaced in the direction of the vectorsthe temperature of the arc in the center of the ellipse maximum and gradually decreases towards the edges of the ellipse. When implementing the proposed method of welding width of the zone of action of the arc on the item (the minor axis of the ellipse) is approximately on the order bolumu impact at the moment of passing under the arch. The temperature of the surface area with each pass under the arc increases and reaches its maximum when the plot goes along the line AB (Fig. 3), coinciding with a plane perpendicular to the axis of the piece and passing through forming a non-consumable electrode from the deposited layer.

If this plane goes to the right of point a (Fig. 3), the line of greatest heat of the arc will take place on the already deposited layer, thus reducing thermal impact at point a decreases the volume microsurvey baths, and the weld surface is subjected to less heat and is heated to the temperature close to the melting point of the metal and, as a result, rasplavlennyi metal additives with the base.

If the plane perpendicular to the axis of the piece and passing through forming a non-consumable electrode is located to the left of point a (Fig. 3), the line of greatest heat of the arc will be held on enablewindow surface. The latter will overheat and fuse slightly, will fuse slightly stronger additive will increase the amount microsurvey baths. The liquid metal from the surface of the workpiece is blown by an electric arc, and on the surface was datalo thickness.

Thus, this feature provides optimum conditions for the existence microsurvey baths, its size, and thus the conditions for the formation of a thin and uniform thickness.

Based on the above, the applicant came to the conclusion on the conformity of the proposed technical solution the criterion of "inventive step".

When performing the deposition process of the proposed method surfaced roller turns a little thick, solid, well fused with the base and the previous roller. This is achieved due to the small size of the weld pool, and a slight excess of the temperature of the metal bath above the melting point of the metal. Mikroshemy deposited metal crystallize immediately after the exit from the zone of action of the arc due to heat in body parts.

The deposition process proceeds almost without formation of spray when properly selected surfacing mode, as there are no conditions for the formation of spray. Liquid metal additives covers the base of the cone additives a very thin layer and well kept on the insertion tool due to surface tension forces. The liquid metal additives on the item occurs only in Microfine near point a, ucitelem the runout of the workpiece surface, when there is a periodic separation of the additive from the surface of the part.

The possibility of obtaining a layer of small thickness and high quality layer and full fused with metal parts due to the action of the whole complex of features in the claims and in the first place, high deposition rates, the corresponding diameter of the additive and the small size of the welding bath.

An example of the method of welding.

Installation for implementing the method argon-arc welding of cylindrical parts up and running (Fig. 5). Installation involves the following basic mechanisms: -serial screw-cutting lathe, which serves to effect the rotation of the parts and the supply of S; surfacing the head, which is mounted on the caliper screw-cutting lathe. Surfacing the head includes a mechanism for imparting insertion tool rotational motion and exercise constant axial force preload additives F; on the head is mounted special argon-arc burner; equipment for hardfacing process: electrical panel and remote control, apparatus for feeding argon; -rectifier welding VDU-1201.

When overlaying the shaft of steel 45 with a diameter of 40 mm are used Lugol= 80flight additives L=5 mm, interelectrode gap 2 mm

The surfacing mode.

Speed details 2,33-1the supply of S=0.4 mm/Rev, speed additives 46,7 with-1, the axial force F=20 H, U=16 B, J=425 And argon flow rate 5 l/min.

Welding of parts made in the following order.

The item is fixed in the centers of a lathe. Surfacing the head is applied to the neck of the details and setting of the mouthpiece and argon-arc burner installation according to the parameters given above. Before the end of additives sharpened on a cone at angle 2and the additive is removed from the workpiece at a distance of 5...6 mm

The sequence of the process. Turn on the rotation part, served the argon gas in the cylinder, a voltage is applied to the electrode and workpiece, and ignited the arc between the tungsten electrode and the part. Arc is generated using an oscillating voltage or by shorting a carbon rod electrode gap. The surface is heated by the arc within 4.. .6 C. turn on the rotation of additives and filing. When contacting the additive with the item additive exerts a constant force F, the primary roller. Included filing S caliper machine attached to the caliper surfacing head and neck is deposited on the entire length (Fig. 6). The end of the deposition process is a common "stop" button: in arc voltage, argon, drive machine drive speed and wire feed.

The specified surfacing mode gives full fusion layer with the base layer thickness 0.25 mm; welding cervical length of 25 mm approximately 28 C. If an additive to warm up on the departure from the secondary power source current J1= 180 A at U1=4 B, the thickness of the cladding is increased to 0.5 mm by Changing the values of U1and J1(Fig. 4) you will receive intermediate values of thickness of the surfacing.

The proposed method of welding gives a minimum roughness of the deposited layer that allows you to assign an allowance for further processing (grinding) within 0.1...0.15 mm per side. When restoring parts with small wear to the proposed method of welding saves filler metal 4...6 times in comparison with the method adopted for the prototype.

The proposed method of welding can be used in engineering, for example in the manufacture of shafts, when the surface of the shaft journals requires giving special properties (the key is more efficient than known methods of welding or deposition of metal even when using expensive consumables since the proposed method of welding gives small thickness of the cladding at a relatively high process performance.


Claims

Way high-speed argon-arc welding of cylindrical parts in which the surface of the rotating parts is heated by an electric arc to a state close to melting, while in contact with the surface of the part lead additive which is served with a constant axial force in the arcing zone, rotating additive around its axis, characterized in that the end face of the additive pre-formed into the shape of a cone with the angle at the vertex 2, additive Orient the longitudinal axis relative to the axis of rotation of the workpiece at an angle= 75...88combining forming the latter with a generatrix of the cone additives, and heat the end of additives to plastic state, and additive rotate with the matching condition vector of the peripheral speed of the base of the cone in magnitude and direction with the vector of the peripheral speed forming parts, and the line of action of the vectors of the peripheral speed of the additive and the details at the point of coincidence combine with the plane, perp the OYA.

 

Same patents:

The invention relates to mechanical engineering and can be used in welding production

The invention relates to the field of welding and can be used in arc welding with a consumable electrode in the medium of shielding gasses, and can find application in various industries in the manufacture of structures of the active metals of medium and high thickness: titanium, aluminum and magnesium alloys

Tungsten electrode // 2162779
The invention relates to arc welding tungsten cermet electrode shielding gas

The invention relates to mechanical engineering and can be used in welding production

The invention relates to mechanical engineering and can be used in welding production

The invention relates to arc welding with non-consumable electrode and can be used in various engineering industries in the manufacture of critical structures of medium and high thickness
The invention relates to mechanical engineering and can be used in welding production

The invention relates to mechanical engineering and can be used in welding production

The invention relates to mechanical engineering and can be used in welding production

The invention relates to welding and can be used for restoration and repair of worn parts

The invention relates to welding equipment and can be used in the repair and restoration of worn parts by welding

The invention relates to welding technology can be used in the repair and restoration of worn parts by welding

The invention relates to welding equipment and can be used in the repair and restoration of worn parts by welding
The invention relates to the field of powder metallurgy, in particular to methods of processing of powder materials using processes of electron-beam welding, and can be used to restore worn surfaces of various products

The invention relates to the welding processes aimed at repair products, such as structural elements of a steam turbine

The invention relates to welding, in particular to the welding head for welding and surfacing products in inert gas, and may find application in the manufacture of welded structures in various engineering industries

The invention relates to the field of engineering, namely the technology of induction welding durable powder alloys, for example, to friction and moving the pair of machines and equipment transport vehicles, including cars, locomotives, track and road cars, parts superstructure
The invention relates to the welding process, and in particular to methods of electric arc welding for application to the surface details of a special composite layers having high wear resistance

The invention relates to a method of welding with non-consumable electrode and can be used for automatic welding of thin-walled blade surfaces of the parts in all industries

FIELD: processes for surfacing with use of lying electrode, possibly restoration of worn surfaces of parts in different industry branches.

SUBSTANCE: method for surfacing bead of rollers of road building machines comprises steps of arranging roller in such a way that its axis is vertical; dividing surfaced zone of bead by technological sectors; forming electrodes of n mutually joined rods bent along arcs of sectors and arranging them on surfaced area of respective sector with gap; supplying flux and additive powder material to surfaced zone; connecting electrode and part with power source for exciting electric arc and performing surfacing; placing electrodes on sectors of bead simultaneously along the whole circle; electrically connecting front end of one electrode with bead; at surfacing narrow beads, forming electrodes of n mutually joined rods arranged one over another.

EFFECT: enlarged manufacturing possibilities of method for surfacing parts with annular worn surface, lowered cost, enhanced efficiency of process.

3 cl, 5 dwg, 1 ex

Up!