CN110834179B - Axial continuous path friction stir material increase manufacturing process for large thin-wall high-cylinder ring piece - Google Patents

Abstract

A large-scale thin-wall high-cylinder ring piece axial continuous path stirring friction additive manufacturing process comprises the steps of firstly determining the size and the number of plates for a standard increment ring piece; then, preparing a layer 1 standard increment ring piece; then carrying out axial continuous path stirring friction additive welding on the 2 nd layer of plate; then carrying out multilayer axial continuous path friction stir welding additive manufacturing on the 3 rd-N layer circulating large ring piece; finally, machining is carried out on the lower end face of the 1 st layer and the upper end face of the Nth layer, and the large ring piece which meets the axial height of the large ring piece and is good in tissue uniformity is obtained; the invention reasonably solves the preparation problem of the large thin-wall cylindrical part monomer, effectively reduces the number of key holes and obtains good ring forming effect.

Description

Axial continuous path friction stir material increase manufacturing process for large thin-wall high-cylinder ring piece

Technical Field

The invention belongs to the field of large ring piece forming manufacturing processes, and particularly relates to an axial continuous path friction stir material increase manufacturing process for a large thin-wall high-cylinder ring piece.

Background

Currently, the common manufacturing techniques for thin-walled cylindrical parts are ring rolling and spinning techniques. The ring rolling of the large and medium-sized ring pieces needs a multi-specification ring rolling mill, and the large ring pieces, particularly the ring pieces with the diameter of more than 10 meters, are formed in multiple passes, so that the required forming force is large, the quality control is difficult, the eccentric problem is easy to occur, and the ring rolling method is difficult to be applied to the thin-wall cylindrical piece with the large height. The spinning of the cored die is difficult to be suitable for forming and manufacturing a cylindrical part with the diameter of more than 2.5 meters, the spinning of the paired wheels is suitable for forming and manufacturing a large-diameter cylindrical part, but the spinning is easy to be unstable when the height is large, and at present, forming equipment with the diameter of more than 10 meters does not exist.

Chinese patent (publication No. CN 106925884B) proposes an axial stacking type friction stir welding additive forming process of a large thin-wall ring, a radial-axial hot rolling technology is adopted to prepare a ring monomer, but the large thin-wall ring serving as the additive monomer cannot be directly produced by radial-axial hot rolling, the processing cost is high, and the efficiency is low. Chinese patent (publication No. CN 107020447B) proposes a composite laminated friction stir welding additive forming process for large thick-wall cylindrical parts, adopts friction stir welding to carry out radial and axial laminated welding, continuously fills welding wires, and does not consider the material performance problem at a keyhole; and the blank size is too big, and its organization uniformity control is difficult, and in addition also has great requirement to equipment and place, causes higher waste of material and energy. The corresponding auxiliary clamping process is complex, the control difficulty is high, the performance quality of the welding surface is poor, and the preparation precision and quality of the large ring piece cannot be met.

For the forming and manufacturing of the large-diameter ring piece, the large-size ring piece can be formed by adopting the additive manufacturing of friction stir welding, but no effective method is used for preparing the single ring piece, the problem of processing the key hole defect is not considered, the key hole repair welding is more, and the integral structural performance is influenced.

Disclosure of Invention

In order to overcome the defects, the invention aims to provide an axial continuous path stirring friction additive manufacturing process for a large thin-wall high-cylinder ring piece, which reasonably solves the preparation problem of a large thin-wall cylinder piece monomer, effectively reduces the number of key holes and obtains a good ring forming effect.

In order to achieve the purpose, the invention adopts the technical scheme that:

an axial continuous path friction stir additive manufacturing process for a large thin-wall high-cylinder ring piece comprises the following steps:

step 1: determining the size and the number of the plates for the standard increment ring piece;

1.1 bending to form the strip material for the standard ring piece;

the size of the large thin-wall cylindrical part manufactured by forming is the outer diameter D, the wall thickness T and the height H, and the large thin-wall cylindrical part is manufactured by N layers of standard incremental ring parts in a continuous path stirring friction welding axial additive mode;

layer 1 standard increment ring: outer diameter d₁Not less than D, wall thickness t₁The outer diameter of the axial material increase standard increment ring piece is equal to that of the large thin-wall cylindrical piece, and the height h is equal to that of the large thin-wall cylindrical piece₁A +2c, the length of the welding seam is uniformly fixed as a, and a gap c needs to be left at the two initial ends of the axial welding seam;

2, N layers of standard incremental ring pieces: outer diameter d_n≥D，t_n≥T，n＝2,3,…,N, the outer diameter of the axial additive standard increment ring piece is the same as that of the large thin-wall cylindrical piece, and the height h of the axial additive standard increment ring piece is equal to that of the large thin-wall cylindrical piece_nA + c is more than or equal to a, the starting point of the axial weld seam is continuous with the circumferential weld seam from the 2 nd layer, and only a gap c is left at the upper end of the axial direction;

layer 1 standard increment panel: length l₁＝πd₁Thickness ═ t₁The thickness of the plate is the thickness of the standard increment ring piece; width b₁＝h₁The width of the plate is the height of the single-layer ring piece;

2, N layers of standard incremental plates: length l_n＝πd_nThickness ═ t_nN is 2,3, … N, and the thickness of the plate is the thickness of the standard increment ring piece; width b_n＝h_nThe width of the plate is the height of the single-layer ring piece;

according to the forming corresponding relation of the plate, the side surface of the end part of the plate is an inclined plane, and the length difference is as follows:

namely, a bending formula is obtained, and the two ends of the plate need to be chamfered in advance:

1.2 calculating the number of the plates;

after the axial additive meets the height requirement, machining is carried out on the lower end face of the 1 st layer and the upper end face of the N th layer, machining allowances needing subsequent machining are respectively left on two axial starting sides of the ring piece after the axial additive, the diameter phi of the shaft shoulder of the stirring head influences the width of a welding seam and the size of a key hole, and the machining allowances e on the lower end face of the 1 st layer₁Not less than c, the upper end face machining allowance e of the Nth layer₂≥c+φ/2；

The number of the required material increase welding plates is N, and the requirements are as follows:

step 2: preparing a layer 1 standard increment ring piece;

2.1 bending the 1 st layer plate into a ring shape;

adopting horizontal processing, using two groups of three-roller devices to do rotary motion to roll and bend the plate along the plate, driving the plate to be bent, elastic and plastic deformed, completing the roll and bend of the plate after the two groups of three-roller devices simultaneously complete a half circle, and contacting the tail end to wait for welding;

2.2 friction stir welding the ring piece into a closed standard increment ring piece at the end point;

clamping by using a clamping mechanism on two sides, after two groups of three-roller devices are clamped and fixed at the bending end point, arranging a supporting device on the inner side of the circular ring, and sealing the ring after performing friction stir welding on the outer side from bottom to top to obtain a standard incremental ring;

and step 3: axial friction stir material increase welding is realized on the 2 nd layer of plate;

positioning and clamping the standard incremental ring piece, and adding plates with corresponding sizes in the axial direction of the standard incremental ring piece for axial material increase; the 2 nd layer is axially placed, the difference between the initial position and the 1 st layer is S, the length of a reserved welding line is required to be not less than the length of a standard welding line and not more than half of the whole, and a +2c is not less than S and not more than l/2; the stirring head enters from the keyhole reserved in the layer 1 to start welding, firstly, the bending and friction stir welding are carried out along the longer part of the plate, the stirring head and the supporting device at the outer side are followed, and the plate is welded to one end of the plate at the outer side of the circular ring along the circumference; the stirring head enters from the keyhole reserved in the layer 1 again, the bending and the friction stir welding are reversely carried out along the short part of the plate, and the plate is welded to the other end of the plate at the outer side of the circular ring along the circumference; after the stirring head finishes the whole circumference, clamping the end point of the ring, finally, finishing the ring closing after the alignment, and performing friction stir welding upwards to close the ring, thereby realizing the continuous welding path of the friction stir welding;

and 4, step 4: multilayer axial friction stir welding additive manufacturing of the 3-N layer circulating large ring piece;

continuing to perform axial additive manufacturing on the large ring piece according to the step 3, sequentially completing the 3 rd layer, the 4 th layer and the like by the same continuous path until the size requirement of the final large ring piece is met, and completing multilayer axial friction stir welding additive manufacturing forming of the large bending ring piece;

and 5: machining the lower end face of the 1 st layer and the upper end face of the N-th layer;

after the material increase is finished, the machining allowance left for the welding seam by friction stir welding needs to be removed, the upper end face and the lower end face are machined, and the machining allowance e for the lower end face of the 1 st layer₁Not less than c, the upper end face machining allowance e of the Nth layer₂And c + phi/2 or more, and finally obtaining the large ring piece which meets the axial height of the large ring piece and has good tissue uniformity.

Compared with the prior art, the invention has the following advantages:

firstly, aiming at a ring piece monomer for additive manufacturing, a standard increment ring piece with good roundness and uniform tissue can be obtained through bending, so that the processing precision and the surface quality of a large ring piece can be effectively guaranteed, and the problems of cracks, delamination, eccentricity and the like which may occur in ring piece rolling are eliminated; the size, the number and the processing steps of the monomers can be designed and adjusted according to the actual processing requirements of the large ring piece, so that the applicability and the reliability are enhanced; the continuous path welding of friction stir effectively reduces the number of key holes, reduces the material waste and the performance defect caused by friction stir welding, and improves the material utilization rate.

Drawings

FIG. 1 is a flow diagram of the process of the present invention.

FIG. 2 is a schematic view of a single layer wrap of the present invention, wherein FIG. 1 is a schematic view of a layer 1 standard increment ring and FIG. 1 is a schematic view of a sheet material used in the layer 1 standard increment.

FIG. 3 is a schematic view of the multi-layer axial roll bending of the present invention, wherein FIG. 3(a) is a schematic view of the 2 nd to N th layer standard increment ring members, and FIG. 3(b) is a schematic view of the 2 nd to N th layer standard increment sheet materials.

FIG. 4 is a schematic length diagram of a friction stir weld of the present invention, wherein FIG. 4(a) is a schematic length diagram of a layer 1 weld and FIG. (b) is a schematic length diagram of a layer 2-N weld.

Figure 5 is a schematic illustration of a standard incremental ring preparation of the present invention.

Fig. 6 is a schematic view of a continuous path design of a multi-layer axial additive manufacturing stir head according to an embodiment of the present invention, where (a) is a clamping map, (b) is a schematic view of a longer portion of a plate material being rolled and friction stir welded, and (c) is a schematic view of a shorter portion of a plate material being rolled and friction stir welded.

Fig. 7 is a schematic diagram of a continuous path design of a multi-layer axial additive manufacturing tool according to example two S/2, where (a) is a positioning and clamping diagram, (b) is a schematic diagram of the left-side semi-circular portion of the plate being rolled and friction stir welded, and (c) is a schematic diagram of the right-side semi-circular portion of the plate being rolled and friction stir welded.

Fig. 8 is a diagram of the effect of continuous-path additive forming according to the present invention, where (a) is a diagram of the effect of embodiment one-S-a +2c, and (b) is a diagram of the effect of embodiment two-S-l/2.

Detailed Description

The invention is described in detail below with reference to the figures and examples.

First embodiment, as shown in fig. 1, an axial continuous path friction stir additive manufacturing process for a large thin-walled high-cylindrical ring member includes the following steps:

step 1: determining the size and the number of the plates for the standard increment ring piece;

1.1 bending to form the strip material for the standard ring piece;

the size of the large thin-wall cylindrical part manufactured by forming is the outer diameter D, the wall thickness T and the height H, and the large thin-wall cylindrical part is manufactured by N layers of standard incremental ring parts in a continuous path stirring friction welding axial additive mode;

layer 1 standard increment ring: layer 1 Standard increment Ring As shown in FIG. 2(a), the outer diameter d₁Not less than D, wall thickness t₁The outer diameter of the axial material increase standard increment ring piece is equal to or larger than T, the outer diameter of the axial material increase standard increment ring piece is the same as that of the large thin-wall cylindrical piece, the pressing amount of friction stir welding needs to be reserved in the thickness direction, and the outer diameter and the wall thickness of the axial material increase standard increment ring piece are not smaller than the corresponding size of the large thin-wall cylindrical piece; the length distribution of the layer 1 welding seam is as shown in figure 4(a), and the height h₁A +2c, considering the requirement of axial welding performance, uniformly fixing the length of a welding line as a, ensuring stable welding process and consistent performance, leaving a gap c at the two initial ends of the axial welding line, facilitating the insertion and withdrawal of a stirring head, effectively ensuring the processing quality of friction stir welding, wherein the height of the axial material increase standard increment ring piece is not less than the sum of the length of the welding line and the gaps at the two ends;

2, N layers of standard incremental ring pieces: the sizes of the 2 nd to N th layers of standard increment ring pieces are shown in figure 3(b), and the outer diameter d_n≥D，t_nThe outer diameter of the axial material increase standard increment ring piece is equal to or larger than T, N is equal to 2,3, …, N, the outer diameter of the axial material increase standard increment ring piece is the same as that of the large thin-wall cylindrical piece, the pressing amount of friction stir welding needs to be reserved in the thickness direction, and the outer diameter and the wall thickness of the axial material increase standard increment ring piece are not smaller than the corresponding size of the large thin-wall cylindrical piece; the length distribution of the 2 nd to N th layers of welding seams is shown in figure 4(b), and the height h_nA + c is more than or equal to a + c, considering the requirement of axial welding performance, the starting point of the axial welding seam of the 2 nd layer is continuous with the circumferential welding seam, only a gap c is left at the upper end in the axial direction, and the standard incremental ring pieces of the 2 nd to N th layers are not less than the sum of the length of the welding seam and the gap at the upper end;

layer 1 standard increment panel: layer 1 Standard incremental sheet As shown in FIG. 2(b), length l₁＝πd₁Thickness ═ t₁According to the corresponding relation of plate forming, the length of the plate is related to the outer diameter of the standard incremental ring piece, and the thickness of the plate is the thickness of the standard incremental ring piece; width b₁＝h₁The width of the plate is the height of the single-layer ring piece;

2, N layers of standard incremental plates: the 2 nd to N th layers of standard incremental plates are shown in figure 3(b), and the length is l_n＝πd_nThickness ═ t_nN is 2,3, … N, the length of the plate is related to the outer diameter of the standard incremental ring piece according to the corresponding relation of plate forming, and the thickness of the plate is the thickness of the standard incremental ring piece; width b_n＝h_nThe width of the plate is the height of the single-layer ring piece;

as shown in fig. 3(b), according to the forming corresponding relationship of the plate material, the end shape side of the plate material is an inclined plane, and the length difference x_nComprises the following steps:

namely, a bending formula is obtained, and the two ends of the plate need to be chamfered in advance:

1.2 calculating the number of the plates;

after the axial additive meets the height requirement, machining is carried out on the lower end face of the 1 st layer and the upper end face of the N-th layer, and the influence of the reserved gap on the structural performance of the cylindrical part is removed; the machining allowance required for subsequent machining is respectively left on the two axial initial sides of the ring piece after material increase, as shown in fig. 4, the arrow indicates the welding direction, the distribution of the welding seam position of the friction stir welding is influenced by the number of layers, the diameter phi of the shaft shoulder of the stirring head influences the width of the welding seam and the size of the key hole o, and the machining allowance e of the lower end face of the 1 st layer₁Not less than c, the upper end face machining allowance e of the Nth layer₂≥c+φ/2；

The number of the required material increase welding plates is N, and the requirements are as follows:

step 2: preparing a layer 1 standard increment ring piece;

2.1 the 1 st layer plate is bent into a ring shape to wait for welding;

as shown in fig. 5, horizontal processing is adopted to avoid the influence of the self weight of the large ring piece on the roundness and the precision of the ring piece, and a pair of upright posts 1 are used for clamping the middle of a plate 2 to realize the fixed position and the erection of the plate 2; two sets of three-roller devices 6 are used for synchronously rotating left and right, and walk along the plate 2 to drive the plate 2 to be bent, elastically and plastically deformed; the two groups of three-roller devices 6 reach the end point after walking for half a circle at the same time, the plate 2 is bent, and the tail ends are in contact and wait for welding;

2.2 friction stir welding the ring piece into a closed standard increment ring piece at the end point;

clamping the two sides of the plate 2 by using three-roller devices 6, clamping and fixing the two groups of three-roller devices 6 at the bending end point of the plate 2, arranging a supporting device 3 at the inner side of the circular ring, performing friction stir welding on the outer side of the circular ring from bottom to top by using a stirring needle 4, and then sealing the circular ring to form a linear welding line 5, thus obtaining a standard incremental ring;

axially increasing materials from the 2 nd layer, wherein the difference between the initial position and the 1 st layer along the circumference is S, the length of a reserved welding line is required to be not less than the length of a standard welding line and not more than half of the whole, and the a +2c is not less than S and not more than l/2; fig. 6 is a schematic diagram of S ═ a +2 c.

And step 3: axial friction stir material increase welding is realized on the 2 nd layer of plate;

as shown in fig. 6(a), positioning and clamping the starting position of the standard incremental plate of the layer 2 and the layer 1 by a distance S ═ a +2c, and performing axial additive manufacturing; as shown in fig. 6(b), the stirring head 4 enters from the keyhole left in the layer 1 to start welding, firstly, the bending and friction stir welding are carried out along the longer part of the plate, the outer stirring head 4 and the supporting device 3 are followed, and the plate is welded to one end of the plate at the outer side of the circular ring along the circumference; as shown in fig. 6(c), the stirring head 4 enters from the keyhole left in the layer 1 again, and the plate is reversely bent and friction stir welded along the short part of the plate, and the plate is welded to the other end of the plate at the outer side of the circular ring along the circumference; after the stirring head 4 finishes the whole circumference, the two groups of three-roller devices 6 clamp the end point of the ring, the stirring head 4 finishes the ring closing at the alignment, and the stirring friction welding is carried out upwards to close the ring, so that the continuous welding path of the stirring friction welding can be realized, the number of key holes can be reduced after the welding is finished, and the effect of reducing the defects of the stirring friction welding can be achieved;

and 4, step 4: multilayer axial friction stir welding additive manufacturing of the 3-N layer circulating large ring piece;

and (3) continuing to perform axial additive manufacturing on the large ring piece according to the step (3), sequentially completing the layer (3) and the layer (4) and the like by the same continuous path, and the effect diagram is shown in fig. 8(a), until the size requirement of the final large ring piece is met, completing multilayer axial friction stir welding additive manufacturing forming of the large bending ring piece.

And 5: machining the lower end face of the 1 st layer and the upper end face of the N-th layer;

after the material increase is finished, the machining allowance left for the welding seam by friction stir welding needs to be removed, the upper end face and the lower end face are machined, and the machining allowance e for the lower end face of the 1 st layer₁Not less than c, the upper end face machining allowance e of the Nth layer₂And c + phi/2 or more, and finally obtaining the large ring piece which meets the axial height of the large ring piece and has good tissue uniformity.

In a second embodiment, as shown in fig. 1, an axial continuous path friction stir additive manufacturing process for a large thin-walled high-cylinder ring member includes the following steps:

step 1: determining the size and the number of the plates for the standard increment ring piece;

1.1 bending to form the strip material for the standard ring piece;

the size of the large thin-wall cylindrical part manufactured by forming is the outer diameter D, the wall thickness T and the height H, and the large thin-wall cylindrical part is manufactured by N layers of standard incremental ring parts in a continuous path stirring friction welding axial additive mode;

layer 1 standard increment ring: layer 1 Standard increment Ring As shown in FIG. 2(a), the outer diameter d₁Not less than D, wall thickness t₁The outer diameter of the axial material increase standard increment ring piece is equal to or larger than T, the outer diameter of the axial material increase standard increment ring piece is the same as that of the large thin-wall cylindrical piece, the pressing amount of friction stir welding needs to be reserved in the thickness direction, and the outer diameter and the wall thickness of the axial material increase standard increment ring piece are not smaller than the corresponding size of the large thin-wall cylindrical piece; the length distribution of the layer 1 welding seam is as shown in figure 4(a), and the height h₁A +2c, considering the requirement of axial welding performance, uniformly fixing the length of a welding line as a, ensuring stable welding process and consistent performance, leaving a gap c at the two initial ends of the axial welding line, facilitating the insertion and withdrawal of a stirring head, effectively ensuring the processing quality of friction stir welding, wherein the height of the axial material increase standard increment ring piece is not less than the sum of the length of the welding line and the gaps at the two ends;

2, N layers of standard incremental ring pieces: the sizes of the 2 nd to N th layers of standard increment ring pieces are shown in figure 3(b), and the outer diameter d_n≥D，t_nThe outer diameter of the axial material increase standard increment ring piece is equal to or larger than T, N is equal to 2,3, …, N, the outer diameter of the axial material increase standard increment ring piece is the same as that of the large thin-wall cylindrical piece, the pressing amount of friction stir welding needs to be reserved in the thickness direction, and the outer diameter and the wall thickness of the axial material increase standard increment ring piece are not smaller than the corresponding size of the large thin-wall cylindrical piece; the length distribution of the 2 nd to N th layers of welding seams is shown in figure 4(b), and the height h_nA + c is more than or equal to a + c, considering the requirement of axial welding performance, the starting point of the axial welding seam of the 2 nd layer is continuous with the circumferential welding seam, only a gap c is left at the upper end in the axial direction, and the standard incremental ring pieces of the 2 nd to N th layers are not less than the sum of the length of the welding seam and the gap at the upper end;

layer 1 standard increment panel: layer 1 Standard incremental sheet As shown in FIG. 2(b), length l₁＝πd₁Thickness ═ t₁According to the corresponding relation of the plate forming, the length of the plate is related to the outer diameter of the standard increment ring piece, and the thickness of the plate is the standard incrementThe thickness of the ring; width b₁＝h₁The width of the plate is the height of the single-layer ring piece;

2, N layers of standard incremental plates: the 2 nd to N th layers of standard incremental plates are shown in figure 3(b), and the length is l_n＝πd_nThickness ═ t_nN is 2,3, … N, the length of the plate is related to the outer diameter of the standard incremental ring piece according to the corresponding relation of plate forming, and the thickness of the plate is the thickness of the standard incremental ring piece; width b_n＝h_nThe width of the plate is the height of the single-layer ring piece;

as shown in fig. 3(b), according to the forming corresponding relationship of the plate material, the end shape side of the plate material is an inclined plane, and the length difference x_nComprises the following steps:

namely, a bending formula is obtained, and the two ends of the plate need to be chamfered in advance:

1.2 calculating the number of the plates;

after the axial additive meets the height requirement, machining is carried out on the lower end face of the 1 st layer and the upper end face of the N-th layer, and the influence of the reserved gap on the structural performance of the cylindrical part is removed; the machining allowance required for subsequent machining is respectively left on the two axial initial sides of the ring piece after material increase, as shown in fig. 4, the arrow indicates the welding direction, the distribution of the welding seam position of the friction stir welding is influenced by the number of layers, the diameter phi of the shaft shoulder of the stirring head influences the width of the welding seam and the size of the key hole o, and the machining allowance e of the lower end face of the 1 st layer₁Not less than c, the upper end face machining allowance e of the Nth layer₂≥c+φ/2；

The number of the required material increase welding plates is N, and the requirements are as follows:

step 2: preparing a layer 1 standard increment ring piece;

2.1 the 1 st layer plate is bent into a ring shape to wait for welding;

as shown in fig. 5, horizontal processing is adopted to avoid the influence of the self weight of the large ring piece on the roundness and the precision of the ring piece, and a pair of upright posts 1 are used for clamping the middle of a plate 2 to realize the fixed position and the erection of the plate 2; two sets of three-roller devices 6 are used for synchronously rotating left and right, and walk along the plate 2 to drive the plate 2 to be bent, elastically and plastically deformed; the two groups of three-roller devices 6 reach the end point after walking for half a circle at the same time, the plate 2 is bent, and the tail ends are in contact and wait for welding;

2.2 friction stir welding the ring piece into a closed standard increment ring piece at the end point;

clamping the two sides of the plate 2 by using three-roller devices 6, clamping and fixing the two groups of three-roller devices 6 at the bending end point of the plate 2, arranging a supporting device 3 at the inner side of the circular ring, performing friction stir welding on the outer side of the circular ring from bottom to top by using a stirring needle 4, and then sealing the circular ring to form a linear welding line 5, thus obtaining a standard incremental ring;

axially increasing materials from the 2 nd layer, wherein the difference between the initial position and the 1 st layer along the circumference is S, the length of a reserved welding line is required to be not less than the length of a standard welding line and not more than half of the whole, and the a +2c is not less than S and not more than l/2; fig. 7 is a schematic diagram of S ═ l/2;

and step 3: axial friction stir material increase welding is realized on the 2 nd layer of plate;

as shown in fig. 7(a), positioning and clamping the starting position of the standard incremental plate of the layer 2 and the layer 1 by a distance S ═ l/2, and performing axial additive manufacturing; as shown in fig. 7(b), the stirring head 4 enters from the keyhole left in the layer 1 to start welding, firstly, the curling and friction stir welding are carried out along the semicircular part on the left side, the stirring head 4 on the outer side and the supporting device 3 are followed, and the plate is welded to one end of the plate on the outer side of the circular ring along the circumference; as shown in fig. 7(c), the stirring head 4 enters from the keyhole left in the layer 1 again, and the plate is reversely curled and friction stir welded along the semicircular part on the right side of the plate, and is welded to the other end of the plate on the outer side of the circular ring along the circumference; after the stirring head 4 finishes the whole circumference, the two groups of three-roller devices 6 clamp the end point of the ring, the stirring head 4 finishes the ring closing at the alignment, and the stirring friction welding is carried out upwards to close the ring, so that the continuous welding path of the stirring friction welding can be realized, the number of key holes can be reduced after the welding is finished, and the effect of reducing the defects of the stirring friction welding can be achieved;

and 4, step 4: multilayer axial friction stir welding additive manufacturing of the 3-N layer circulating large ring piece;

continuing to perform axial additive manufacturing on the large ring piece according to the step 3, sequentially completing the 3 rd layer, the 4 th layer and the like by the same continuous path, and the like, wherein the effect diagram is shown in fig. 8(b), and completing multilayer axial friction stir welding additive manufacturing forming of the large bending ring piece until the size requirement of the final large ring piece is met;

and 5: machining the lower end face of the 1 st layer and the upper end face of the N-th layer;

after the material increase is finished, the machining allowance left for the welding seam by friction stir welding needs to be removed, the upper end face and the lower end face are machined, and the machining allowance e for the lower end face of the 1 st layer₁Not less than c, the upper end face machining allowance e of the Nth layer₂And c + phi/2 or more, and finally obtaining the large ring piece which meets the axial height of the large ring piece and has good tissue uniformity.

The invention bends the strip plate material coil into the standard increment ring piece, realizes the axial friction stir continuous path welding process by friction stir welding, and can effectively reduce the number of key holes and obtain better ring forming effect by continuous welding path.

Claims (1)

1. The axial continuous path friction stir material additive manufacturing process of the large thin-wall high-cylinder ring piece is characterized by comprising the following steps of:

step 1: determining the size and the number of the plates for the standard increment ring piece;

1.1 bending to form the strip material for the standard ring piece;

the size of the large thin-wall cylindrical part manufactured by forming is the outer diameter D, the wall thickness T and the height H, and the large thin-wall cylindrical part is manufactured by N layers of standard incremental ring parts in a continuous path stirring friction welding axial additive mode;

layer 1 standard increment ring: outer diameter d₁Not less than D, wall thickness t₁The outer diameter of the axial material increase standard increment ring piece is equal to that of the large thin-wall cylindrical piece, and the height h is equal to that of the large thin-wall cylindrical piece₁A +2c, the length of the welding seam is uniformly fixed as a, and the axial welding seam needs to leave a gap at the two initial endsc；

2, N layers of standard incremental ring pieces: outer diameter d_n≥D，t_nThe outer diameter of the axial additive standard increment ring is equal to that of the large thin-wall cylindrical part, and the height h is equal to that of the large thin-wall cylindrical part_nA + c is more than or equal to a, the starting point of the axial weld seam is continuous with the circumferential weld seam from the 2 nd layer, and only a gap c is left at the upper end of the axial direction;

layer 1 standard increment panel: length l₁＝πd₁Thickness ═ t₁The thickness of the plate is the thickness of the standard increment ring piece; width b₁＝h₁The width of the plate is the height of the single-layer ring piece;

2, N layers of standard incremental plates: length l_n＝πd_nThickness ═ t_nN is 2,3, … N, and the thickness of the plate is the thickness of the standard increment ring piece; width b_n＝h_n＝_nThe width of the plate is the height of the single-layer ring piece;

according to the forming corresponding relation of the plate, the side surface of the end part of the plate is an inclined plane, and the length difference is as follows:

namely, a bending formula is obtained, and the two ends of the plate need to be chamfered in advance:

1.2 calculating the number of the plates;

after the axial additive meets the height requirement, machining is carried out on the lower end face of the 1 st layer and the upper end face of the N th layer, machining allowances needing subsequent machining are respectively left on two axial starting sides of the ring piece after the axial additive, the diameter phi of the shaft shoulder of the stirring head influences the width of a welding seam and the size of a key hole, and the machining allowances e on the lower end face of the 1 st layer₁Not less than c, the upper end face machining allowance e of the Nth layer₂≥c+φ/2；

The number of the required material increase welding plates is N, and the requirements are as follows:

step 2: preparing a layer 1 standard increment ring piece;

2.1 bending the 1 st layer plate into a ring shape;

adopting horizontal processing, using two groups of three-roller devices to do rotary motion to roll and bend the plate along the plate, driving the plate to be bent, elastic and plastic deformed, completing the roll and bend of the plate after the two groups of three-roller devices simultaneously complete a half circle, and contacting the tail end to wait for welding;

2.2 friction stir welding the ring piece into a closed standard increment ring piece at the end point;

clamping by using a clamping mechanism on two sides, after two groups of three-roller devices are clamped and fixed at the bending end point, arranging a supporting device on the inner side of the circular ring, and sealing the ring after performing friction stir welding on the outer side from bottom to top to obtain a standard incremental ring;

and step 3: axial friction stir material increase welding is realized on the 2 nd layer of plate;

positioning and clamping the standard incremental ring piece, and adding plates with corresponding sizes in the axial direction of the standard incremental ring piece for axial material increase; the 2 nd layer is axially placed, the difference between the initial position and the 1 st layer is S, the length of the reserved welding line is not less than the length of the standard welding line and not more than half of the whole, and the sum of (a +2c) and S is not less than l_n2; the stirring head enters from the keyhole reserved in the layer 1 to start welding, firstly, the bending and friction stir welding are carried out along the longer part of the plate, the stirring head and the supporting device at the outer side are followed, and the plate is welded to one end of the plate at the outer side of the circular ring along the circumference; the stirring head enters from the keyhole reserved in the layer 1 again, the bending and the friction stir welding are reversely carried out along the short part of the plate, and the plate is welded to the other end of the plate at the outer side of the circular ring along the circumference; after the stirring head finishes the whole circumference, clamping the end point of the ring, finally, finishing the ring closing after the alignment, and performing friction stir welding upwards to close the ring, thereby realizing the continuous welding path of the friction stir welding;

and 4, step 4: multilayer axial friction stir welding additive manufacturing of the 3-N layer circulating large ring piece;

continuing to perform axial additive manufacturing on the large ring piece according to the step 3, sequentially completing the 3 rd layer, the 4 th layer and the like by the same continuous path until the size requirement of the final large ring piece is met, and completing multilayer axial friction stir welding additive manufacturing forming of the large bending ring piece;

and 5: machining the lower end face of the 1 st layer and the upper end face of the N-th layer;

after the material increase is finished, the machining allowance left for the welding seam by friction stir welding needs to be removed, the upper end face and the lower end face are machined, and the machining allowance e for the lower end face of the 1 st layer₁Not less than c, the upper end face machining allowance e of the Nth layer₂And c + phi/2 or more, and finally obtaining the large ring piece which meets the axial height of the large ring piece and has good tissue uniformity.

Images