CN112192152A - Annular curved surface titanium alloy workpiece and welding method thereof - Google Patents

Annular curved surface titanium alloy workpiece and welding method thereof Download PDF

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Publication number
CN112192152A
CN112192152A CN202011052908.9A CN202011052908A CN112192152A CN 112192152 A CN112192152 A CN 112192152A CN 202011052908 A CN202011052908 A CN 202011052908A CN 112192152 A CN112192152 A CN 112192152A
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China
Prior art keywords
welding
workpiece
titanium alloy
curved surface
blanking
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Inventor
颉文峰
李琳
杜培升
李新孝
钟堂
张晓锋
顾炜芬
辛宏
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AECC Aviation Power Co Ltd
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AECC Aviation Power Co Ltd
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Priority to CN202011052908.9A priority Critical patent/CN112192152A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23P—METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P15/00—Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00—Arc welding or cutting
    • B23K9/16—Arc welding or cutting making use of shielding gas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/08—Non-ferrous metals or alloys
    • B23K2103/14—Titanium or alloys thereof

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Arc Welding In General (AREA)

Abstract

The invention relates to an annular curved surface titanium alloy workpiece and a welding method thereof, wherein the welding method comprises the following steps of 1, calculating an angle alpha of an oblique welding seam on the formed workpiece, wherein the angle alpha is not perpendicular to the direction of forming tension according to the direction of the tension when the workpiece is formed; step 2, determining the size of a flat plate blanking blank according to the size of a formed workpiece and the angle alpha of the oblique welding seam, and blanking to prepare a blanking blank; step 3, welding the blanking blank to form a welding cylinder, wherein no welding wire is added in the welding process; and 4, carrying out postweld heat treatment on the oblique welding line to finish welding. The tension formed when the welding seam is designed into the oblique welding seam is decomposed in two directions of the parallel welding seam and the vertical welding seam, so that the load in the vertical direction of the welding seam is reduced, the integrity of the surface of the welding seam is kept, the roughness of the surface is small, the crack sensitivity is low, and the problem of cold forming and cracking of the welding seam of the annular curved surface titanium alloy plate welding part with large drawing amount is solved.

Description

Annular curved surface titanium alloy workpiece and welding method thereof
Technical Field
The invention belongs to the technical field of metal plate welding, and particularly belongs to an annular curved surface titanium alloy workpiece and a welding method thereof.
Background
Titanium and titanium alloy have the excellent performances of light weight, high specific strength, high temperature resistance, corrosion resistance and the like, have wider working temperature range and good welding performance, and are widely applied to the aviation industry. Titanium alloy sheet weldments are often employed in non-critical load-bearing components due to their practicality and economy. For straight cylinder and cone cylinder type sheet metal welding parts with simple structures, the welding seam does not bear the forming load, or the bearing forming load is very small and is not enough to pull and crack the welding seam, but for curved sheet metal welding parts with complex structures and large drawing amount, because the drawing amount is large during cold forming, when the deformation amount reaches the limit, the curved sheet metal welding parts can crack from the weakest part, the tensile strength of the welding seam is often lower than that of the original material, and particularly when the welding seam is vertical to the tensile force borne during forming, the tensile force borne by the welding seam is the largest, and the welding seam becomes the initial cracking part.
And the surface of the welding seam is frequently required to be polished after welding, particularly for some precision formed parts or flow channel parts, the welding seam is always required to be polished to be flush with the main body on a drawing, the thickness of the welding seam is the same as that of the base body, and if cracking is required during forming, the welding seam is cracked first. Generally, the roughness of a polished welding seam is difficult to reach a higher level, the roughness is often inferior to that of a base body, and for a titanium alloy part, the titanium alloy part has high sensitivity to the roughness of the surface, and when the roughness of the surface is high, cracks are easily induced during forming, so that the titanium alloy part is cracked.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides the annular curved surface titanium alloy workpiece and the welding method thereof, which reduce the load in the vertical direction of the welding line, avoid the cracking problem of the welding line in a lower tensile stress state, have simple operation and high welding quality and increase the welding efficiency.
In order to achieve the purpose, the invention provides the following technical scheme:
a welding method of an annular curved surface titanium alloy workpiece comprises the following steps,
step 1, calculating an angle alpha of an oblique welding seam on a formed workpiece, wherein the angle alpha is not perpendicular to the direction of forming tension according to the direction of the tension when the workpiece is formed;
step 2, determining the size of a flat plate blanking blank according to the size of a formed workpiece and the angle alpha of the oblique welding seam, and blanking to prepare a blanking blank;
step 3, welding the blanking blank to form a welding cylinder, wherein no welding wire is added in the welding process;
and 4, carrying out postweld heat treatment on the oblique welding line to finish welding.
Preferably, in step 1, the angle α of the fillet weld is calculated according to the following formula:
α＝arcsin(k×σb×δ×L/F)；
wherein F is the forming force, delta is the thickness of the workpiece material, sigmabThe tensile strength of the workpiece material, L the length of the weld, and k the tensile strength coefficient of the weld.
Preferably, in the step 2, laser blanking is adopted for processing the blanking blank.
Preferably, in the step 2, the number of the blanking blanks is not less than two, and a plurality of the blanking blanks are welded in a surrounding mode to form the welded cylinder.
Preferably, in step 3, before welding the blanking blank, the blanking blank is firstly subjected to acid cleaning, and after a re-melting layer is removed, polishing and assembling are sequentially performed on a joint part of the blanking blank, welding is performed.
Preferably, in the step 3, automatic argon arc welding is adopted for welding, and the blanking blank is welded to form a welding cylinder.
Preferably, in step 4, the post-weld heat treatment mode is vacuum annealing.
Preferably, the tensile strength of the oblique welding seam is not less than 85% of the tensile strength of the parent metal of the forming workpiece.
Preferably, the forming mode of processing the welding cylinder into the formed workpiece is punch forming.
An annular curved surface titanium alloy workpiece is welded by the welding method based on any one of the above.
Compared with the prior art, the invention has the following beneficial technical effects:
according to the welding method of the annular curved surface titanium alloy workpiece, the formed tensile force is decomposed in two directions of the parallel welding seam and the vertical welding seam when the welding seam is designed to be the oblique welding seam, so that the load of the welding seam in the vertical direction is reduced, and the problem of cracking of the welding seam in a lower tensile stress state is avoided; the requirement that the welding seam is flush with the base body can be met without polishing the welding seam after welding without adding wires, the integrity of the surface of the welding seam is kept, the roughness of the surface is small, and the crack sensitivity is low. The cold forming is carried out under the original state without grinding the welding line, so that the force in the vertical direction of the welding line is reduced, the crack sensitivity is reduced, and the problem of cold forming cracking of the welding line of the annular curved surface titanium alloy plate welding piece with large drawing amount is solved.
Furthermore, welding is performed through automatic argon arc welding, the forming quality of an oblique welding seam is more stable, the width and the surplus height of the welding seam are more uniform, no stress concentration point exists in the welding seam, and the quality of the welding seam is improved.
Furthermore, the oblique welding seam is subjected to vacuum annealing, so that the welding stress of the welding seam is completely removed, and the subsequent forming process is fully prepared.
Furthermore, by adopting laser blanking to process blanking blanks, the titanium alloy is prevented from being polluted when contacting with other specific substance elements due to the particularity of the material, and further the welding quality is prevented from being influenced.
Drawings
FIG. 1 is a schematic illustration of a single blanked blank according to an embodiment of the present invention;
FIG. 2 is a schematic view of welding two blanking blanks according to an embodiment of the present invention;
FIG. 3 illustrates a schematic view of a cylinder formed by rounding and welding two blanking blanks according to an embodiment of the present invention;
FIG. 4 is a schematic view of a barrel formed into a workpiece according to an embodiment of the present invention.
In the drawings: 1, blanking blank; 2, welding a cylinder body; 3, forming a workpiece; 4, pressing the blank in the upper process; 5, pressing the blank in the lower process; 6, welding a welding seam of the blanking blank; and 7, a seam after the rounding welding.
Detailed Description
The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.
The invention relates to a welding method of an annular curved surface titanium alloy workpiece, which comprises the following steps,
step 1, calculating an angle alpha of an oblique welding seam on a formed workpiece 3, which is not perpendicular to the forming tension direction, according to the direction of the tension when the workpiece is formed;
step 2, determining the size of a flat plate blanking blank 1 according to the size of the formed workpiece 3 and the angle alpha of the oblique welding seam, and blanking to prepare a blanking blank 1;
step 3, welding the blanking blank 1 to form a welding cylinder 2, wherein no welding wire is added in the welding process;
and 4, carrying out postweld heat treatment on the oblique welding line to finish welding.
The invention provides a welding method of an annular curved surface titanium alloy workpiece, wherein oblique welding seams which are not vertical to the direction of tensile stress are welded by automatic argon arc welding without adding wires, and are cold-formed in the original state without polishing the welding seams, so that the force in the vertical direction of the welding seams is reduced, the crack sensitivity is reduced, and the cold-forming cracking of the welding seams of the annular curved surface titanium alloy sheet welding workpiece with large drawing amount is prevented.
The formed tension is decomposed in two directions of a parallel welding seam and a vertical welding seam when the welding seam is designed into an oblique welding seam, so that the load of the welding seam in the vertical direction is reduced, and the problem of cracking of the welding seam in a lower tensile stress state is avoided; by adopting automatic welding, the forming quality of the welding seam is more stable, the width and the rest height of the welding seam are more uniform, and the welding seam does not have a stress concentration point; the requirement that the welding seam is flush with the base body can be met without polishing the welding seam after welding without adding wires, the integrity of the surface of the welding seam is kept, the roughness of the surface is small, and the crack sensitivity is low.
Examples
A welding method of an annular curved surface titanium alloy workpiece comprises the following steps:
step 1, designing an angle alpha of a bias weld: according to the direction of the tensile force during forming, calculating the angle alpha between the welding line on the cylinder body and the forming tensile force direction, namely the tensile force during forming can be borne when the angle formed by the welding line and the tensile force direction is a certain degree;
step 2, designing a blanking blank 1 and blanking: and designing a cylinder structure according to the forming size and the forming mode of the workpiece, and calculating the size of the cylinder. Calculating the size of a flat plate blanking blank 1 and blanking by combining the angle alpha of the oblique welding line, wherein the material pollution problem needs to be considered in the blanking of the titanium alloy part;
step 3, welding: performing necessary pre-welding preparation on a blank to be welded, welding the blank into a barrel by adopting automatic argon arc welding, wherein no welding wire is added during welding, and a welded seam keeps an original state after welding and is not polished;
step 4, postweld heat treatment: the heat treatment mode and system are selected according to the grade of the material, the standard of the material, the thickness of the material and the like. In order to completely eliminate welding stress and improve the formability of the material, the titanium alloy post-welding heat treatment mode adopts vacuum annealing;
step 5, forming: and integrally forming the cylinder into an annular curved surface for subsequent further processing.
Taking a zero-level stator inner ring of a certain engine supercharging stage as an example, the part is made of material with the grade TA1, the thickness of the part is 1mm, the diameter is larger than phi 800mm, the height is about 80mm, the structure is an annular curved surface plate welding part, the radial difference between the outer shape and the inner circle is large, and the formed deep drawing amount is large.
Firstly, welding seams are perpendicular to the end faces of the ring pieces, manual argon arc welding is adopted for welding, welding wires are added, the welding seams are polished to be flush with the main body after welding, and the welding seams are cracked during forming. And then keeping the welding line and the end face of the ring piece to be vertical, adopting automatic argon arc welding for welding, adding a welding wire, polishing the welding line to be flush with the main body after welding, and cracking from the welding line during molding. And then keeping the welding line and the end face of the ring piece to be vertical, adopting automatic argon arc welding without adding welding wires, and cracking from the welding line during forming without grinding the welding line after welding.
As shown in fig. 1 to 4, a method for welding an annular curved surface titanium alloy workpiece, wherein an oblique welding seam which is not perpendicular to a tensile stress direction is welded by automatic argon arc welding without adding wires, and is cold-formed in an original state without grinding the welding seam, comprises the following specific steps:
1. designing an angle of a bias weld: under the condition that the welding line can bear forming load, the forming force is averagely decomposed in the vertical direction and the parallel direction of the welding line, the bearing capacity of the welding line is mainly reflected in the vertical direction of the welding line, the forming force is F, the included angle between the direction of the forming force and the direction of the welding line is alpha, and the component force borne by the parallel direction of the welding line is F1The component force in the vertical direction of the weld is F2The thickness of the workpiece material is delta, and the tensile strength of the workpiece material is sigmabThe length of the welding seam is L, the tensile strength coefficient of the welding seam is k, and the sectional area of the welding seam in the parallel direction is S.
S＝δ×L；
F2＝k×σb×S＝k×σb×δ×L；
And F2＝F×sinα；
F × sin α ═ k × σb×δ×L；
sinα＝k×σb×δ×L/F；
α＝arcsin(k×σb×δ×L/F)；
From the above equation, as the forming force F increases, the fillet angle α decreases.
For a given forming tension, for a welding seam without adding welding wires, the tensile strength of the welding seam should not be less than 85% of that of the base metal, namely the tensile strength coefficient k of the welding seam is not less than 0.85,
when k is 0.85, α is arcsin (0.85 σ ═ arcsinb×δ×L/F)
At this time, α is minimum.
2. Designing a blanking blank and blanking: according to the forming mode of the formed workpiece 3, the forming is carried out by stamping, the welding cylinder 2 is a conical cylinder consisting of two sections of fan-shaped blanking blanks 1, the size of the flat blanking blank is calculated by combining the angle alpha of an oblique welding line, and then the blanking is carried out by adopting a laser cutting mode, so that the titanium alloy is prevented from being polluted when being contacted with other specific substance elements due to the self-specificity of the material;
3. welding: pickling the blanks 1 to be welded, removing a remelted layer at the joint part, polishing and assembling, welding the two blanks 1 into a welding cylinder 2 by adopting longitudinal automatic argon arc welding according to the welding seams 6 of the blanks, adding no welding wire during welding, keeping the welding seams in an original state after welding and not grinding; forming a seam 7 after the rolling welding after the welding;
4. postweld heat treatment: vacuum annealing is adopted to completely remove welding stress, and full preparation is made for a forming process;
5. molding: and (3) integrally forming the welding cylinder body 2 into an annular curved surface by adopting punch forming, forming a formed workpiece 3 with an upper process blank holder 4 and a lower process blank holder 5, and further processing the formed workpiece.
By using the method, the formed tensile force is decomposed in two directions of a parallel welding seam and a vertical welding seam, the load of the welding seam in the vertical direction is reduced, the cracking problem of the welding seam in a lower tensile stress state is avoided, and in the welding process, the included angle between the welding seam and the end face, namely the included angle between the welding seam and the forming force can be directly simplified to be 45 degrees according to experience; by adopting automatic welding, the forming quality of the welding seam is more stable, the width and the rest height of the welding seam are more uniform, and the welding seam does not have a stress concentration point; the requirement that the welding seam is flush with the base body can be met without polishing the welding seam after welding without adding wires, the integrity of the surface of the welding seam is kept, the roughness of the surface reaches Ra0.4, and the crack sensitivity is greatly reduced.

Claims (10)

1. A welding method of an annular curved surface titanium alloy workpiece is characterized by comprising the following steps,
step 1, calculating an angle alpha of a diagonal weld on a formed workpiece (3) which is not perpendicular to the forming tension direction according to the direction of the tension when the workpiece is formed;
step 2, determining the size of a flat plate blanking blank (1) according to the size of the formed workpiece (3) and the angle alpha of the oblique welding line, and blanking to prepare the blanking blank (1);
step 3, welding the blanking blank (1) to form a welding cylinder (2), wherein no welding wire is added in the welding process;
and 4, carrying out postweld heat treatment on the oblique welding line to finish welding.
2. The method for welding the annular curved surface titanium alloy workpiece according to claim 1, wherein in the step 1, the angle α of the oblique welding seam is calculated according to the following formula:
α＝arcsin(k×σb×δ×L/F)；
wherein F is the forming force, delta is the thickness of the workpiece material, sigmabThe tensile strength of the workpiece material, L the length of the weld, and k the tensile strength coefficient of the weld.
3. The welding method of the annular curved surface titanium alloy workpiece as claimed in claim 1, wherein in the step 2, laser blanking is adopted for processing the blanking blank (1).
4. The welding method of the annular curved surface titanium alloy workpiece as claimed in claim 1, wherein in the step 2, the number of the blanking blanks (1) is not less than two, and a plurality of the blanking blanks (1) are welded in a surrounding manner to form the welding cylinder (2).
5. The welding method of the annular curved surface titanium alloy workpiece as claimed in claim 1, wherein in the step 3, before the welding of the blanking blank (1), the blanking blank (1) is firstly pickled, and after the joint part of the blanking blank (1) is sequentially subjected to remelting layer removing, polishing and assembling, the welding is carried out.
6. The welding method of the annular curved surface titanium alloy workpiece according to the claim 1, characterized in that in the step 3, automatic argon arc welding is adopted for welding, and the blanking blank (1) is welded to form the welding cylinder (2).
7. The method for welding the annular curved surface titanium alloy workpiece according to claim 1, wherein in the step 4, the post-welding heat treatment mode is vacuum annealing.
8. The method for welding an annular curved surface titanium alloy workpiece according to claim 1, wherein the tensile strength of the oblique welding seam is not less than 85% of that of the parent metal of the formed workpiece (3).
9. The welding method of the annular curved surface titanium alloy workpiece as claimed in claim 1, wherein the forming mode of processing the welding cylinder (2) into the formed workpiece (3) is punch forming.
10. An annular curved surface titanium alloy workpiece, which is formed by welding based on the welding method of any one of claims 1 to 9.
CN202011052908.9A 2020-09-29 2020-09-29 Annular curved surface titanium alloy workpiece and welding method thereof Pending CN112192152A (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2612723A1 (en) * 2012-01-04 2013-07-10 Siemens Aktiengesellschaft Bevelled weld seam and measuring method
CN108856966A (en) * 2018-07-20 2018-11-23 北京星航机电装备有限公司 A kind of 1.5mm titanium alloy is not added an automatic TIG welding and connects method
CN109483019A (en) * 2018-12-03 2019-03-19 江西洪都航空工业集团有限责任公司 The non-silk filling Automatic Pulsed Argon Arc Welding technique of 1~3mm thickness titanium alloy under a kind of atmospheric environment
CN109590662A (en) * 2019-01-07 2019-04-09 上海航天精密机械研究所 Automatic soldering device and welding method is adjusted in titanium alloy barrel body circumferential weld
CN110524115A (en) * 2019-08-02 2019-12-03 西安飞机工业（集团）有限责任公司 A kind of welding method reducing weldment deformation

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2612723A1 (en) * 2012-01-04 2013-07-10 Siemens Aktiengesellschaft Bevelled weld seam and measuring method
CN108856966A (en) * 2018-07-20 2018-11-23 北京星航机电装备有限公司 A kind of 1.5mm titanium alloy is not added an automatic TIG welding and connects method
CN109483019A (en) * 2018-12-03 2019-03-19 江西洪都航空工业集团有限责任公司 The non-silk filling Automatic Pulsed Argon Arc Welding technique of 1~3mm thickness titanium alloy under a kind of atmospheric environment
CN109590662A (en) * 2019-01-07 2019-04-09 上海航天精密机械研究所 Automatic soldering device and welding method is adjusted in titanium alloy barrel body circumferential weld
CN110524115A (en) * 2019-08-02 2019-12-03 西安飞机工业（集团）有限责任公司 A kind of welding method reducing weldment deformation

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Application publication date: 20210108