CN106925883A - The radially superimposed formula agitating friction welding of large thick-wall ring increases material forming technology - Google Patents

Abstract

Radial layered friction stir welding additive forming process for large thick-walled rings. Diameter-axial hot rolling technology is used to prepare thin-walled rings. Additive forming to stacked biaxial friction stir welding. The welding wire used for welding needs to be preheated by a laser heater to facilitate the plasticization of the welding wire during the welding process. The metal is micro-forged to ensure that the metal structure of the formed weld seam is almost completely formed into a weld nugget; after welding along the weld seam for a week, the welding wire continuously fills the keyhole, and at the same time the stirring head is slowly withdrawn from the workpiece, thus completing the first The thin-walled ring is welded alone; finally, the thick-walled ring is radially stacked and friction-stir welded to form additives. The invention can significantly improve the utilization rate of materials, reduce energy consumption, and improve the overall performance of the product.

Description

Radial layered friction stir welding additive forming process for large thick-walled rings

technical field

The invention belongs to the technical field of forming large metal rings, and in particular relates to a radially stacked friction stir welding additive forming process for large thick-walled rings.

Background technique

With the rapid development of my country's petrochemical, electric power, shipbuilding, aerospace and equipment manufacturing industries, the demand for ring parts is increasing, with more and more varieties and larger sizes, and the types of materials used are increasingly diversified. For small and medium-sized rings, the more common forming technology is to use ring rolling machines for ring rolling. However, for large rings, since the forming process requires a huge forming force to complete, large-scale rolling and forging equipment is difficult to manufacture, the manufacturing cost is high, and it is difficult to realize it by rolling technology due to the limitation of the forming capacity of the rolling mill and the forming quality of the product. It takes shape. As the ingot increases, the solidification speed is slow, the material segregation is serious, the grains are coarse and the crack casting defects cannot be completely eliminated in the later rolling and forging process, resulting in partial elongation and strength that cannot meet the design requirements. In actual production, it is very easy to have phenomena such as skin clipping, insufficient cavity filling, and coarse grains. And the successful rolling of large rings is often at the cost of more material loss and higher energy consumption. In addition, the existing friction stir welding is easy to form defects such as flash, pit and keyhole at the weld. Therefore, the traditional processing methods of large thick-walled rings can no longer meet the market's high-efficiency, energy-saving and material-saving manufacturing requirements, and superior performance.

Contents of the invention

In order to overcome the above-mentioned shortcomings, the object of the present invention is to provide a radially stacked friction stir welding additive forming process for large thick-walled rings, through which a high-performance large thick-walled ring with the metal structure at the weld completely forming a weld nugget can be prepared , can significantly improve the utilization rate of materials, reduce energy consumption, and improve the overall performance of products.

In order to achieve the above object, the technical scheme adopted in the present invention is:

Radial layered friction stir welding additive forming process for large thick-walled rings, including the following steps:

1) Single rolling forming of thin-walled ring parts: use radial-axial hot rolling technology to make thin-walled ring parts, and prepare metal ingots to prepare friction stir welding through blanking, billet making, ring rolling, heat treatment and machining processes. Thin-walled ring monomers required for additive forming;

2) Thin-walled ring single piece radially stacked biaxial friction stir welding additive forming: first, the first thin-walled ring single piece 1-1 and the second thin-walled ring piece single piece 1-2 are coaxially and radially stacked butted Clamped on the welding workbench as the workpiece to be welded; then, the welding wire 4 is preheated by the laser heater 5, and the preheated welding wire 4 is sent to the weld 2-1 of the workpiece to be welded by the feeder 3 Then, the first vertical stirring head 1 and the second vertical stirring head 2 rotating at a high speed are inserted into the upper and lower sides of the joint of the workpiece to be welded respectively, and the first vertical stirring head 1 rotates counterclockwise, and the second vertical stirring head 2 The vertical stirring head 2 rotates counterclockwise, while the first vertical stirring head 1 and the second vertical stirring head 2 move counterclockwise along the welding seam 2-1 around the end face of the ring; the feeder 3 rotates with the stirring head The same tangential linear velocity continuously transports the welding wire 4 to the weld 2-1, and the welding wire 4 is continuously stirred into the weld 2-1 by the first vertical stirring head 1 and the second vertical stirring head 2 at the same time, The rotation rate of the first vertical stirring head 1 and the second vertical stirring head 2 are the same, and the size of the rotation rate needs to make the metal around the weld seam 2-1 of the workpiece to be welded and the welding wire 4 can be heated to a plastic state, and the control temperature is low Based on the melting point of the metal, the plasticized metal continuously fills the cavity formed by the movement of the stirring needle under the stirring and extrusion of the first vertical stirring head 1 and the second vertical stirring head 2, and gradually cools and solidifies to form Weld 2-1; In addition, while the first vertical stirring head 1 and the second vertical stirring head 2 are stirring and welding, the ultrasonic exciter 6 is turned on, and micro-forging is performed on the plasticized metal at the weld 2-1 , so that the metal structure at the weld 2-1 is almost completely formed into a weld nugget; the first vertical stirring head 1 and the second vertical stirring head 2 move forward along the weld 2-1 and stir welding for one week, the first vertical stirring head The stirring speed of the stirring head 1 and the second vertical stirring head 2 is constant, while the first vertical stirring head 1 and the second vertical stirring head 2 are slowly withdrawn from the weld 2-1 of the workpiece to be welded, and the feeder 3 Continue to convey the welding wire 4 in the keyhole. At this time, the rate and time at which the feeder 3 continues to convey the welding wire 4 need to match the extraction rate and time of the first vertical stirring head 1 and the second vertical stirring head 2, Until the welding wire 4 that continues to be transported is plasticized and fills the keyhole, the radial stacked friction stir welding additive forming process of the first ring thin-walled ring is completed;

3) Radial layered friction stir welding additive forming of thick-walled ring parts: according to the radial layered friction stir welding additive forming process of thin-walled ring parts in step 2), the thin-walled ring parts are superimposed and welded coaxially and radially ring by ring , complete the second ring, the third ring, ······, the nth ring thin-walled single radial layered friction stir welding additive forming, until the final welded workpiece meets the product requirements, and the large-scale thick-walled ring is completed Radial layered friction stir welding additive forming of wall ring parts.

The first vertical stirring head 1 and the second vertical stirring head 2 have the same structure, including a shoulder A1 and a stirring needle B1, and the shoulder A1 is planar.

The material property of the welding wire 4 is the same as that of the workpiece to be welded.

The laser heater 5 is used for preheating the welding wire 4 to ensure that the welding wire 4 and the metal at the weld seam 2-1 of the workpiece to be welded reach a plasticized state at the same time during the welding process.

The present invention has the following advantages:

1. Compared with the large-scale thick-walled ring prepared by the traditional free forging process, the present invention utilizes the radial stacked friction stir welding additive forming process to prepare the large-scale thick-walled ring, because the metal around the weld 2-1 of the workpiece to be welded Under the stirring and extrusion action of the stirring head, the welding wire 4 continuously undergoes plastic deformation and fills into the cavity formed after the stirring needle moves, and gradually cools and solidifies to form the weld 2-1, and the formed weld 2-1 There will be no flashes and pits, and the appearance of weld 2-1 is uniform and smooth without defects, and the mechanical properties of welded joints are better than those of fusion welding. Moreover, the friction stir welding additive forming process is easy to operate. Before welding, it is only necessary to use an organic solvent to remove the grease on the joint surface, without opening the bevel to remove the oxide film, and without removing the reinforcement after welding. consume.

2. During the process of friction stir welding additive forming, the first vertical stirring head 1 and the second vertical stirring head 2 move forward along the weld 2-1 and stir welding for one week, the first vertical stirring head 1 and the second When the vertical stirring head 2 is slowly withdrawn from the weld seam 2-1 of the workpiece to be welded, the feeder 3 continues to transport the welding wire 4 into the keyhole until the welding wire 4 that continues to be transported is plasticized and fills the keyhole So far, therefore, keyhole defects will not be formed at the tail end of the formed weld 2-1.

3. Use ultrasonic exciter 6 to micro-forge the plasticized metal during the welding process from both sides of the joint surface of the workpiece to be welded, forging the inclusions inside the material and the fiber structure during rolling/extrusion of the metal profile, Make the structure finer and evenly distributed, and reduce it as much as possible so as to avoid the formation of thermal machine affected zone and heat affected zone at the weld, so that the metal structure of the formed weld 2-1 can reach the level of almost completely forming the weld nugget, avoiding Defects such as coarse grains and cracks appear, and the mechanical properties of the obtained welded joint are better than those of the existing friction stir welded joint.

Description of drawings

Figure 1 is a flow chart of the forming process of the present invention.

Fig. 2 is a schematic diagram of the working principle of the forming process of the present invention.

Fig. 3 is a partial enlarged view of A in Fig. 2 .

Fig. 4 is the structural diagram of vertical stirring head 1 and 2 of the present invention, and figure (a) is a front view, and figure (b) is a left view.

Fig. 5 is a 1/2 sectional view of the thick-walled ring formed by the present invention.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings.

Referring to Figure 1, Figure 2 and Figure 3, the radial stacked friction stir welding additive forming process for large thick-walled rings includes the following steps:

1) Thin-walled ring single-piece rolling forming: According to the production requirements of the product and the requirements of the thin-walled ring single-piece processing drawings, the radial-axial hot rolling technology is used to make thin-walled ring billets, and the prepared metal ingots are passed through blanking, billet making, Ring rolling, heat treatment and machining processes are used to prepare thin-walled ring monomers required for friction stir welding additive forming;

2) Thin-walled ring single piece radially stacked biaxial friction stir welding additive forming: first, the first thin-walled ring single piece 1-1 and the second thin-walled ring piece single piece 1-2 are coaxially and radially stacked butted Clamped on the welding workbench as the workpiece to be welded; then, the welding wire 4 is preheated by the laser heater 5, and the preheated welding wire 4 is sent to the weld 2-1 of the workpiece to be welded by the feeder 3 Then, the first vertical stirring head 1 and the second vertical stirring head 2 rotating at a high speed are inserted into the upper and lower sides of the joint of the workpiece to be welded respectively, and the first vertical stirring head 1 rotates counterclockwise, and the second vertical stirring head 2 The vertical stirring head 2 rotates counterclockwise, while the first vertical stirring head 1 and the second vertical stirring head 2 move counterclockwise along the welding seam 2-1 around the end face of the ring; the feeder 3 rotates with the stirring head The same tangential linear velocity continuously transports the welding wire 4 to the weld 2-1, and the welding wire 4 is continuously stirred into the weld 2-1 by the first vertical stirring head 1 and the second vertical stirring head 2 at the same time, The rotation rate of the first vertical stirring head 1 and the second vertical stirring head 2 is the same, because the friction heat between the first vertical stirring head 1 and the second vertical stirring head 2 and the workpiece to be welded, the workpiece to be welded The metal around the seam and the welding wire 4 are heated, so the rotation rate needs to ensure that the heat generated can heat the metal around the weld 2-1 of the workpiece to be welded and the welding wire 4 to a plastic state, and the temperature needs to be controlled lower than that of the metal Under the agitation and extrusion of the first vertical stirring head 1 and the second vertical stirring head 2, the plasticized metal continuously fills the cavity formed by the movement of the stirring needle, and gradually cools and solidifies to form a weld 2-1; In addition, while the first vertical stirring head 1 and the second vertical stirring head 2 are stirring and welding, the ultrasonic exciter 6 is turned on, and micro-forging is performed on the plasticized metal at the weld 2-1, reducing The formation of the thermal machine-affected zone and the heat-affected zone at the small weld 2-1 makes the metal structure at the weld 2-1 approximately completely form a weld nugget; the first vertical stirring head 1 and the second vertical stirring head 2 are welded along the After seam 2-1 moves forward and stirs and welds for one week, the stirring speed of the first vertical stirring head 1 and the second vertical stirring head 2 remains unchanged, and at the same time, the first vertical stirring head 1 and the second vertical stirring head 2 start from Slowly withdraw from the weld seam 2-1 of the workpiece to be welded, and the feeder 3 continues to deliver the welding wire 4 to the keyhole. Match the extraction rate and time of the second vertical stirring head 2 until the welding wire 4 that continues to be transported is plasticized and fills the keyhole, so as to prevent the residual hole in the weld seam and ensure the continuous structure of the welded joint at the retracted position And the material performance is stable, and the first ring thin-walled ring single radial layered friction stir welding additive forming process has been completed;

3) Radial layered friction stir welding additive forming of thick-walled ring parts: according to the radial layered friction stir welding additive forming process of thin-walled ring parts in step 2), the thin-walled ring parts are superimposed and welded coaxially and radially ring by ring , complete the second ring, the third ring, ······, the nth ring thin-walled single radial layered friction stir welding additive forming, until the final welded workpiece meets the product requirements, and the large-scale thick-walled ring is completed Radial layered friction stir welding additive forming of wall ring parts.

The ultrasonic exciter 6 performs micro-forging on the plasticized metal during the welding process from both sides of the joint surface of the workpiece to be welded, and forges the inclusions inside the material and the fiber structure during rolling/extrusion of the metal profile to make the structure more Small and evenly distributed, as small as possible so as to avoid the formation of thermal machine-affected zone and heat-affected zone at the weld, so that the metal structure of the formed weld 2-1 can reach the level of almost completely forming a weld nugget, and avoid the appearance of grains Defects such as coarseness and cracks can be eliminated, and the mechanical properties of welded joints can be improved.

Referring to FIG. 4 , the first vertical stirring head 1 and the second vertical stirring head 2 have the same structure, including a shaft shoulder A1 and a stirring pin B1 , and the shaft shoulder A1 is planar. The specific type of the shoulder of the stirring head can realize that the shoulder is always tangent to the joint surface of the workpiece to be welded during the friction stir welding process, so as to ensure that the welding seam wire 4 is continuously filled to the welding seam 2-1 under the action of friction stir welding During the welding process, pits are prevented from appearing at the weld seam 2-1, and the welding quality of the weld seam 2-1 is improved, thereby realizing friction stir welding additive forming.

Referring to Fig. 5, a half-section view of a large thick-walled ring processed by radial stacking friction stir welding additive forming process, taking radially stacked four layers as an example, the inner diameter of the large thick-walled ring is R1 , the outer diameter is R2, and the four-layer thin-walled ring monomers are respectively the first thin-walled ring monomer 1-1, the second thin-walled ring monomer 1-2, the third thin-walled ring monomer 1-3 and the fourth thin-walled ring monomer 1-4, Friction stir welding additive forming to obtain three welds, namely weld 2-1, weld 2-2 and weld 2-3.

Claims (4)

1. the radially superimposed formula agitating friction welding of large thick-wall ring increases material forming technology, it is characterised in that comprise the following steps：

1) thin-walled ring monomer roll forming：Thin-walled ring base is carried out using footpath-axial direction hot rolling technique, by ready metal Ingot prepares agitating friction and welds the thin-walled increased required for material shapes by blanking, base, looping mill rolling, heat treatment and process for machining Ring monomer；

2) the radially superimposed formula Double shaft stirring friction welding of thin-walled ring monomer increases material shaping：First, by the first thin-walled ring monomer (1-1) and the second thin-walled ring monomer (1-2) using clamping in the form of coaxial radially superimposed docking on welding bench as treating Welder's part；Then, welding wire (4) is preheated by laser heater (5), with feed appliance (3) by the welding after preheating Wire rod (4) is sent to weld seam (2-1) place of workpiece to be welded；Then, the first vertical mixing head (1) of rotation and second vertical is stirred at a high speed Mix the both sides up and down that head (2) penetrates workpiece joint to be welded respectively, first vertical mixing head (1) rotation in a counterclockwise direction, second Vertical mixing head (2) rotation in a counterclockwise direction, while the first vertical mixing head (1) and the second vertical mixing head (2) are along weld seam (2-1) is around ring end face counterclockwise movement；The tangential linear velocity of identical is toward weld seam (2- when feed appliance (3) is with stirring-head rotation 1) place persistently conveys welding wire (4), welding wire (4) while by the first vertical mixing head (1) and the second vertical mixing head (2) Weld seam (2-1) is ceaselessly stirred into, the first vertical mixing head (1) is identical with the autorotation speed of the second vertical mixing head (2), from rotating speed Rate size needs to make workpiece weld seam (2-1) surrounding metal to be welded and welding wire (4) to be heated to mecystasis, and control temperature Degree less than metal fusing point, the stirring and extruding of the metal of plasticizing in the first vertical mixing head (1) and the second vertical mixing head (2) Under effect, the cavity for constantly being formed after the movement of filling mixing needle, and gradually cooled and solidified forms weld seam (2-1)；In addition, first While vertical mixing head (1) and the stirring welding of the second vertical mixing head (2), ultrasonic excitation device (6) is opened, to weld seam (2-1) The metal for locating plasticizing carries out micro- forging treatment, weld seam (2-1) place metal structure form is approximately formed nugget completely；First vertical stirs Mix head (1) and the second vertical mixing head (2) along weld seam (2-1) travel forward stirring welding one week after, the first vertical mixing head (1) Mixing speed with the second vertical mixing head (2) is constant, at the same the first vertical mixing head (1) and the second vertical mixing head (2) from Slowly extracted out in the weld seam (2-1) of workpiece to be welded, feed appliance (3) continues to conveying welding wire (4) in keyhole, now, feeding Device (3) continues to convey the speed of welding wire (4) and time needs and the first vertical mixing head (1) and the second vertical mixing head (2) extraction speed and time matches, complete untill filling up keyhole after the welding wire (4) for continuing to convey is plastified Increase material forming process into the radially superimposed formula agitating friction welding of the first ring thin-walled ring monomer；

3) the radially superimposed formula agitating friction welding of heavy wall ring increases material shaping：According to step 2) thin-walled ring monomer it is radially superimposed The welding of formula agitating friction increases material forming technology, with Axial and radial by ring superposition welding thin-walled ring monomer, completes the second ring, the 3rd Ring ..., the welding of the n-th ring thin-walled ring monomer radially superimposed formula agitating friction increase material shaping, the work until being eventually welded into shape Part meets product requirement, then complete the radially superimposed formula agitating friction welding of large thick-wall ring and increase material shaping.

2. the radially superimposed formula agitating friction welding of large thick-wall ring according to claim 1 increases material forming technology, and it is special Levy and be：The first described vertical mixing head (1) is identical with the structure of the second vertical mixing head (2), including the shaft shoulder (A1) and stirs Pin (B1) is mixed, the shaft shoulder (A1) is plane.

3. the radially superimposed formula agitating friction welding of large thick-wall ring according to claim 1 increases material forming technology, and it is special Levy and be：Described welding wire (4) is identical with the material properties of workpiece to be welded.

4. the radially superimposed formula agitating friction welding of large thick-wall ring according to claim 1 increases material forming technology, and it is special Levy and be：Preheating of the described laser heater (5) for welding wire (4), it is ensured that welding wire (4) in welding process with The metal at workpiece weld seam (2-1) place to be welded reaches plastifying state simultaneously.