CN107584227B

CN107584227B - Transverse welding method and weldment

Info

Publication number: CN107584227B
Application number: CN201710506867.8A
Authority: CN
Inventors: 关勇; 王霄腾; 谭星; 王莲芳
Original assignee: Zoomlion Heavy Industry Science and Technology Co Ltd
Current assignee: Zoomlion Heavy Industry Science and Technology Co Ltd
Priority date: 2017-06-28
Filing date: 2017-06-28
Publication date: 2020-09-01
Anticipated expiration: 2037-06-28
Also published as: CN107584227A

Abstract

The invention discloses a transverse welding method, which comprises the following steps: positioning a first workpiece and a second workpiece to be welded to enable surfaces to be welded to be in a transverse welding position; providing a front heat source and a rear heat source, and enabling the to-be-welded positions of the to-be-welded surfaces of the first workpiece and the second workpiece to form a welding seam, wherein the energy density of the front heat source is larger than that of the rear heat source, and the welding seam has a first crystallization direction and a second crystallization direction opposite to the first crystallization direction in the thickness direction of the welding seam. The transverse welding method provided by the embodiment of the invention has the advantages of high welding efficiency, good welding quality, low welding difficulty and the like, and can realize single-side welding and double-side forming without arranging a gasket.

Description

Transverse welding method and weldment

Technical Field

The present invention relates to the field of welding, and in particular, to a transverse welding method and a weldment.

Background

In order to realize the one-side welding and two-side forming of the welding seam, a gasket is arranged on the back side of the welding seam. However, the provision of the gasket has problems of high cost, low efficiency, and the like. Moreover, the back of the welding seam is provided with the liner, so that the temperature gradient in the thickness direction of the welding seam is intensified, and the welding seam forms a more obvious unidirectional crystal form.

When welding the box type part, in order to ensure that the box type part can have sufficient bearing capacity, the process requires that the front surface and the back surface of the box type part realize good forming and the root of a welding line is completely melted through. At present, under the condition that no gasket is arranged, when a box-shaped part is welded by using conventional gas shield welding, molten pool metal flows under the action of gravity, good forming of the back surface cannot be realized, and back surface lack of fusion and welding leakage often occur, so that the bearing area of the box-shaped part is reduced, the quality problems of cracking and the like of the box-shaped part are caused more easily, and the manufacturing of large-scale equipment is severely restricted.

Therefore, when the back surface of the box-shaped member has a large space, the back surface of the box-shaped member is manually subjected to repair welding. However, this results in low welding efficiency, excessive labor intensity, and no guarantee of manual welding quality.

However, if the space on the back surface of the box-shaped member is small, the back surface welding cannot be performed manually. In this case, the back side of the box-shaped member is only provided with a gasket. For the case-shaped part with larger length, the space of the back surface is very narrow, even the back surface of the case-shaped part cannot be provided with the gasket, so that the case-shaped part with larger length has the quality defects of back surface lack of penetration and welding leakage.

Disclosure of Invention

The object of the present invention is to overcome the problems of the prior art by providing a transverse welding method with which a weld having two crystallographic directions can be obtained.

In order to achieve the above object, a first aspect of the present invention provides a transverse welding method including the steps of: positioning a first workpiece and a second workpiece to be welded to enable surfaces to be welded to be in a transverse welding position; providing a front heat source and a rear heat source, and enabling the to-be-welded positions of the to-be-welded surfaces of the first workpiece and the second workpiece to form a welding seam, wherein the energy density of the front heat source is larger than that of the rear heat source, and the welding seam has a first crystallization direction and a second crystallization direction opposite to the first crystallization direction in the thickness direction of the welding seam.

The transverse welding method according to the invention can enable the front heat source to have certain penetrating force on the first workpiece and the second workpiece by utilizing the front heat source with higher energy density to supply heat to the first workpiece and the second workpiece, so that the front heat source can penetrate through the first workpiece and the second workpiece to continuously create the grooves and the through holes.

The rear heat source with small energy can continuously generate a proper amount of liquid metal, and the liquid metal in the molten pool can enter the back surfaces of the first workpiece and the second workpiece through the grooves and the through holes and fill the grooves and the through holes under the action of gravity, surface tension, external mechanical force and the like, and is solidified in a proper time window, namely before flowing is generated. Therefore, quality defects such as flowing, undercut, welding beading and the like can not be generated, so that a welding seam with good and consistent front and back surface forming can be obtained, repair welding on the back surface is not needed so as to eliminate the defects, and a welding seam with good and consistent front and back surface forming can be obtained without back surface back gouging or back surface repair welding, so that one-side welding and two-side forming can be realized under the condition of not arranging a gasket, and the welding efficiency is improved.

Because the front heat source can continuously create the grooves and the through holes, the liquid metal generated by the rear heat source can continuously flow to the back surfaces of the first workpiece and the second workpiece through the grooves and the through holes. Therefore, the front surface and the back surface of the welding seam can be fully and uniformly heated, so that the heat conduction during the crystallization of the welding seam is typical two-dimensional plane conduction, the welding seam has the first crystallization direction and the second crystallization direction opposite to the first crystallization direction in the thickness direction of the welding seam, the internal crystallization form of the welding seam is more symmetrical and uniform, the probability of generating defects of the welding seam is less, and the quality of the welding seam is higher.

In addition, because the prepositioned heat source can generate grooves on the first workpiece and the second workpiece, the grooves do not need to be processed on the first workpiece and the second workpiece before welding. Therefore, the process of processing the groove can be omitted, so that the welding efficiency is improved, a gap is not required to be formed between the first workpiece and the second workpiece, the cross-sectional area of a welding seam is greatly reduced, the consumption of welding materials, the welding deformation and the residual stress are reduced, the difficulty of positioning and clamping the first workpiece and the second workpiece is reduced, and the welding difficulty is reduced.

The box-shaped part, particularly the box-shaped part with larger length, is welded by the transverse welding method according to the embodiment of the invention, so that a gasket is not required to be arranged on the back surface of the box-shaped part, the welding cost is reduced, the welding efficiency is improved, and the back surface of the box-shaped part is not required to be repaired and welded manually, so that the welding efficiency is improved, and the labor intensity is reduced.

Therefore, the transverse welding method has the advantages of high welding efficiency, good welding quality, low welding difficulty and the like, and can realize single-side welding and double-side forming without arranging a gasket.

Preferably, the weld has a crystallographic direction symmetry plane, and the first crystallographic direction and the second crystallographic direction are symmetric with respect to the crystallographic direction symmetry plane in a thickness direction of the weld.

Preferably, a thickness direction of each of the first and second workpieces coincides with a thickness direction of the weld, a thickness of the first workpiece is equal to or greater than a thickness of the second workpiece, wherein the crystallographic direction symmetry plane is parallel to a thickness center plane of the first workpiece, a distance between the crystallographic direction symmetry plane and the thickness center plane of the first workpiece is equal to or less than 1/5 of the thickness of the first workpiece, and preferably, a distance between the crystallographic direction symmetry plane and the thickness center plane of the first workpiece is equal to or less than 1/6 of the thickness of the first workpiece.

Preferably, the coefficient of the height of the front and back faces of the weld is greater than 1 and less than or equal to 3, and preferably, the coefficient of the height of the front and back faces of the weld is greater than 1 and less than or equal to 1.6.

Preferably, the preposed heat source continuously creates a groove and a through hole at the position to be welded, the preposed heat source and the postposed heat source enable the molten pool to perform controlled flow, a part of the molten pool enters the back surface of the first workpiece and the back surface of the second workpiece through the groove and the through hole and another part of the molten pool is filled in the groove and the through hole, so that the heat conduction during the crystallization of the welding seam is two-dimensional plane conduction, preferably, the preposed heat source and the postposed heat source enable the molten pool to perform controlled flow through the redistribution of the gravity, the arc thrust, the electromagnetic force and the surface tension of the molten pool, and the width of the through hole is 0.5 mm-3 mm.

Preferably, the first workpiece and the second workpiece form a box-shaped part, the box-shaped part is provided with at least one welding seam, and when the number of the welding seams is greater than or equal to 2, at least two welding seams are welded simultaneously.

A second aspect of the invention provides a weldment. A weldment according to an embodiment of the present invention comprises: the welding joint comprises a first workpiece and a second workpiece, wherein the first workpiece and the second workpiece are connected through a welding joint, and the welding joint has a first crystallization direction and a second crystallization direction opposite to the first crystallization direction in the thickness direction of the welding joint.

Drawings

FIG. 1 is a side view of a weld made using a transverse welding method according to an embodiment of the invention;

FIG. 2 is an enlarged view of area A of FIG. 1;

FIG. 3 is a front view of a weld made using a transverse welding method according to an embodiment of the invention;

FIG. 4 is a top view of a weld made using a transverse welding method according to an embodiment of the present invention;

FIG. 5 is a schematic view of the first and second workpieces after the pre-heat source has passed;

FIG. 6 is a schematic view of a weld formed using a transverse welding method according to an embodiment of the present invention;

FIG. 7 is a schematic view of a weld formed using a transverse welding method according to an embodiment of the present invention;

FIG. 8 is a schematic view of a weld formed using a prior art welding method (without a liner);

FIG. 9 is a schematic view of a weld formed using a prior art welding method (gasketed)

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

A transverse welding method according to an embodiment of the present invention is described below with reference to the accompanying drawings. The transverse welding method according to the embodiment of the invention comprises the following steps:

positioning the first workpiece 110 and the second workpiece 120 to be welded so that the surfaces to be welded are in a transverse welding position;

the front heat source 130 and the rear heat source 140 are provided, so that a welding seam 160 is formed at the position to be welded of the surfaces to be welded of the first workpiece 110 and the second workpiece 120, and the energy density of the front heat source 130 is greater than that of the rear heat source 140. Wherein, in the thickness direction of the bead 160, the bead 160 has a first crystallization direction and a second crystallization direction opposite to the first crystallization direction.

Wherein the first crystallographic direction is shown by arrow B in fig. 6, the second crystallographic direction is shown by arrow C in fig. 6, and the thickness direction of the weld 160 is shown by arrow D in fig. 6. The transverse welding may include: and welding a horizontal welding seam on a vertical plane of the workpiece to be welded and welding a horizontal welding seam on an inclined plane of the workpiece to be welded.

In the conventional welding method without providing a gasket, the welding heat input is relatively small in order to prevent welding leakage. Therefore, the front side and the back side of the welding seam are heated unevenly, the heat input quantity of the front side of the welding seam is much larger than that of the back side of the welding seam, and after a heat source passes through the welding seam, because the temperature of the back side of a molten pool is lower than that of the front side, a temperature gradient is generated in the thickness direction of a workpiece. Therefore, in the thickness direction of the workpiece, an asymmetric crystal form, i.e., a unidirectional crystal form, which is crystallized from the heat-affected zones and the root portions on both sides of the weld toward the center of the weld, is formed (as shown in fig. 8).

For the existing welding method with the gasket, the input welding heat is improved to a certain extent compared with the welding heat input by the welding method without the gasket, so that the front side of the welding seam can be fully heated. However, the liner disposed on the back side of the weld bead dissipates heat from the weld root more quickly, resulting in a greater temperature differential across the weld bead. Therefore, the liner provided on the back side of the weld bead exacerbates the temperature gradient in the thickness direction of the weld bead, causing the weld bead to form a more pronounced asymmetric crystal morphology, i.e., a unidirectional crystal morphology, in the thickness direction thereof (as shown in fig. 9).

The transverse welding method according to an embodiment of the present invention may provide heat to the first and

second workpieces

110 and 120 by using the front heat source 130 having a higher energy density, so that the front heat source 130 may have a certain penetrating power to the first and

second workpieces

110 and 120, and thus the front heat source 130 may penetrate the first and

second workpieces

110 and 120 to continuously create the bevel 151 and the via 152 (as shown in fig. 5).

The post-heat source 140 with low energy density can continuously generate a proper amount of liquid metal, and can make the liquid metal in the molten pool enter the back surfaces of the first workpiece 110 and the second workpiece 120 through the groove 151 and the via hole 152 and fill the groove 151 and the via hole 152 through the action of gravity, surface tension, applied mechanical force and the like, and solidify within a proper time window, that is, before the flowing is generated. Therefore, quality defects such as flowing, undercut, welding beading and the like are not generated, so that a welding seam 160 (shown in fig. 6 and 7) with good and consistent front and back forming can be obtained, repair welding on the back is not needed to eliminate the defects, and a welding seam with good and consistent front and back forming is also not needed to be obtained by back gouging or back repair welding, so that one-side welding and two-side forming can be realized without arranging a gasket, and the welding efficiency is improved.

Because the front heat source 130 may continuously create the grooves 151 and vias 152, liquid metal within the molten puddle may be allowed to continuously flow through the grooves 151 and vias 152 to the back sides of the first and

second workpieces

110, 120. Therefore, both the front and back surfaces of the weld 160 can be sufficiently and uniformly heated, so that the heat conduction during the crystallization of the weld 160 is typically two-dimensional planar conduction, so that the weld 160 has the first crystallization direction and the second crystallization direction opposite to the first crystallization direction in the thickness direction of the weld 160, the internal crystallization form of the weld 160 is more symmetrical and uniform, the probability of generating defects in the weld 160 is less, and the quality of the weld 160 is higher.

Furthermore, because the pre-heat source 130 may create the bevel 151 on the first and

second workpieces

110, 120, it is not necessary to machine the bevel on the first and

second workpieces

110, 120 prior to welding. Therefore, the process of processing the groove can be omitted, so that the welding efficiency is improved, a gap is not required to be arranged between the first workpiece 110 and the second workpiece 120, the cross-sectional area of the welding seam 160 is greatly reduced, the consumption of welding materials, the welding deformation and the residual stress are reduced, the difficulty of positioning and clamping the first workpiece 110 and the second workpiece 120 is reduced, and the welding difficulty is reduced.

Therefore, the transverse welding method provided by the embodiment of the invention has the advantages of high welding efficiency, good welding quality, low welding difficulty and the like, and can realize single-side welding and double-side forming without arranging a gasket.

Preferably, pre-heat source 130 creates bevel 151 and via 152 continuously where to be welded, pre-heat source 130 and post-heat source 140 subject the weld puddle to a controlled flow, causing a portion of the puddle to enter the back of first workpiece 110 and the back of second workpiece 120 through bevel 151 and via 152 and another portion of the puddle to fill in bevel 151 and via 152 so as to cause heat conduction when weld 160 crystallizes as a two-dimensional planar conduction.

More preferably, the pre-heat source 130 and the post-heat source 140 provide controlled flow of the bath by redistributing the bath gravity, arc thrust, electromagnetic force, and bath surface tension. The width of the via 152 may be 0.5 mm to 3 mm.

As shown in fig. 6 and 7, the bead 160 may have a crystal direction symmetry plane S1, and the first crystal direction and the second crystal direction may be symmetrical with respect to the crystal direction symmetry plane S1 in the thickness direction of the bead 160. Therefore, the internal crystal form of the welding seam 160 is more symmetrical and uniform, the possibility of generating defects in the welding seam 160 is further reduced, and the quality of the welding seam 160 is further improved.

When the first and

second workpieces

110, 120 form the box-shaped member 170, the front and

rear heat sources

130, 140 act on the flat plate portions of the first and

second workpieces

110, 120. For convenience of description, the flat plate portions of the first workpiece 110 and the first workpiece 110 constituting the box-shaped member 170 are hereinafter referred to as a first workpiece 110, and the flat plate portions of the second workpiece 120 and the second workpiece 120 constituting the box-shaped member 170 are hereinafter referred to as a second workpiece 120.

The thickness direction of each of the first and

second workpieces

110 and 120 may coincide with the thickness direction of the weld 160, and the thickness of the first workpiece 110 may be equal to or greater than the thickness of the second workpiece 120. It will be understood by those skilled in the art that although fig. 1 shows the first workpiece 110 positioned below the second workpiece 120, the first workpiece 110 may also be positioned above the second workpiece 120.

The crystal direction symmetry plane S1 is not a geometric symmetry plane of the bead 160 itself, that is, a portion of the bead 160 located on the front side of the crystal direction symmetry plane S1 and a portion of the bead 160 located on the back side of the crystal direction symmetry plane S1 are not geometrically symmetric with respect to the crystal direction symmetry plane S1. The crystallographic-direction symmetry plane S1 means: the crystal direction (for example, the first crystal direction) of the portion of the bead 160 located on the front side of the crystal direction symmetry plane S1 and the crystal direction (for example, the second crystal direction) of the portion of the bead 160 located on the back side of the crystal direction symmetry plane S1 are symmetrical with respect to the crystal direction symmetry plane S1.

Among them, the crystal direction symmetry plane S1 may be parallel to the thickness center plane S2 of the first workpiece 110, i.e., the crystal direction symmetry plane S1 may be parallel to the thickness center plane of the thicker workpiece, and the distance d1 between the crystal direction symmetry plane S1 and the thickness center plane S2 of the first workpiece 110 may be less than or equal to 1/5 of the thickness of the first workpiece 110. The uniform heat diffusion from the front and back surfaces of the weld 160 thereby forms a substantially symmetrical weld crystal morphology with the thickness center plane S2 of the first workpiece 110 as a plane of symmetry.

Since the crystal direction symmetry plane S1 is parallel to the thickness center plane S2 of the first workpiece 110, the distance d1 between the crystal direction symmetry plane S1 and the thickness center plane S2 is the distance between the crystal direction symmetry plane S1 and the thickness center plane S2 in the thickness direction of the weld 160. Preferably, a distance d1 between the crystal direction symmetry plane S1 and the thickness center plane S2 of the first workpiece 110 may be equal to or less than 1/6 of the thickness of the first workpiece 110. This makes it possible to make the crystal morphology of the weld bead 160 more symmetrical with respect to the thickness center plane S2 of the first workpiece 110.

Preferably, the coefficient of the face-back residual height of the weld 160 may be greater than 1 and equal to or less than 3.

As shown in fig. 6 and 7, a first portion 161 of the weld 160 may extend from the front side beyond the first and

second workpieces

110, 120, and a second portion 162 of the weld 160 may extend from the back side beyond the first and

second workpieces

110, 120. For example, a first portion 161 of the weld 160 may extend rightward from the first and

second workpieces

110, 120, and a second portion 162 of the weld 160 may extend leftward from the first and

second workpieces

110, 120. Here, the left-right direction is shown by an arrow E in fig. 6, and the left-right direction may be the same as the thickness direction of the bead 160, the first crystallization direction may be a right direction, and the second crystallization direction may be a left direction.

The face-back coefficient of the weld 160 is: the ratio of the area of the cross-section of the first portion 161 to the area of the cross-section of the second portion 162. That is, the coefficient of the face-back residual height of the bead 160 obtained by the transverse welding method according to the embodiment of the present invention may be greater than 1 and equal to or less than 3. Wherein each of a cross-section of the first portion 161 and a cross-section of the second portion 162 may be perpendicular to a length direction of the weld 160.

On the other hand, the coefficient of the top-bottom surface residual height of the weld bead obtained by the conventional flat welding without providing the spacer was about 9 (as shown in fig. 8), and the coefficient of the top-bottom surface residual height of the weld bead obtained by the conventional flat welding with providing the spacer was about 2.5 (as shown in fig. 9). Therefore, although the transverse welding method according to the embodiment of the present invention does not require the provision of the liner, the resulting weld 160 has a coefficient of top-to-back surface residual height that is close to that of a weld obtained by flat welding with the liner provided and much smaller than that of a weld obtained by flat welding without the liner provided.

Therefore, by using the transverse welding method according to the embodiment of the present invention, a uniform weld 160 can be obtained, the molding volumes of the front and back surfaces of the weld 160 are closer, the front and back surfaces of the weld 160 are more uniform and full, and the stress concentration degree of the weld 160 can be reduced.

Further preferably, the coefficient of the face-back residual height of the weld 160 may be greater than 1 and 2.5 or less. More preferably, the coefficient of the face-back residual height of the weld 160 may be greater than 1 and equal to or less than 2. Most preferably, the face-to-back coefficient of the weld 160 may be greater than 1 and equal to or less than 1.6. Therefore, more uniform welding seams 160 can be obtained, the molding volumes of the front surface and the back surface of the welding seams 160 are closer, the front surface and the back surface of the welding seams 160 are more uniform and full, and the stress concentration degree of the welding seams 160 can be further reduced.

The transverse welding method according to the embodiment of the invention is particularly suitable for welding workpieces with small back space, such as the box-shaped part 170, because the transverse welding method according to the embodiment of the invention can realize single-side welding and double-side forming. Wherein the welded box 170 has a closed inner and outer edge in cross-section.

That is, the welded box-shaped member 170 may be a member formed by sequentially connecting an upper metal plate, a left metal plate, a lower metal plate, and a right metal plate, and the cross section of the welded box-shaped member 170 may be a quadrangle. The welded box-shaped member 170 has a receiving space therein, and both front and rear ends of the receiving space may be opened. In particular, the box 170 may be a boom arm of a crane, a transfer arm of a concrete pump truck, or the like.

The first and

second workpieces

110 and 120 may be separated before welding, and when the first and

second workpieces

110 and 120 are obtained by cold forming or hot forming, the first and

second workpieces

110 and 120 may be integrally formed.

The length to width ratio of the box section 170 may be (3-30): the length to height ratio of the box 170 may be (3-25): 1. preferably, the box 170 may have a length to width ratio of (10-30): the length to height ratio of the box 170 may be (10-25): 1. more preferably, the box 170 may have a length to width ratio of (10-25): the length to height ratio of the box 170 may be (10-20): 1. among them, the larger the ratio of the length to the height to the width of the box-shaped member 170 is, the more difficult it is to perform the back repair welding, and the more suitable it is to perform the welding by the transverse welding method according to the embodiment of the present invention.

In some examples of the present invention, the positional relationship between the front heat source 130 and the rear heat source 140 is: the first plane is a plane perpendicular to the weld 160, the second plane is a vertical plane parallel to the weld 160, and the third plane is a horizontal plane.

The projection of the center line of the front heat source 130 on the first plane in the direction opposite to the welding direction is a first straight line L1, the projection of the center line of the rear heat source 140 on the first plane in the direction opposite to the welding direction is a fourth straight line L4, and the projection of the weld center line on the first plane in the direction opposite to the welding direction is a seventh straight line L7. The projection of the center line of the front heat source 130 on the second plane in the direction adjacent to at least one of the first workpiece 110 and the second workpiece 120 is a second straight line L2, and the projection of the center line of the rear heat source 140 on the second plane in the direction adjacent to at least one of the first workpiece 110 and the second workpiece 120 is a fifth straight line L5. The center line of the front heat source 130 projects a third straight line L3 downward on the third plane, and the center line of the rear heat source 140 projects a sixth straight line L6 downward on the third plane.

The first plane and the second plane intersect on an eighth straight line L8, and the first plane and the third plane intersect on a ninth straight line L9. That is, the first plane and the second plane are intersecting planes, an eighth straight line L8 is an intersection of the first plane and the second plane, the first plane and the third plane are intersecting planes, and a ninth straight line L9 is an intersection of the first plane and the third plane.

A first included angle α 1 between the first straight line L1 and the fourth straight line L4 is greater than 0 degree and less than or equal to 15 degrees, and a second included angle α 2 between the fourth straight line L4 and the seventh straight line L7 is greater than or equal to-30 degrees (minus 30 degrees) and less than or equal to 30 degrees (as shown in fig. 1 and 2). That is, in a side view, that is, when the first plane is viewed in a direction opposite to the welding direction, the first included angle α 1 is greater than 0 degrees and 15 degrees or less, and the second included angle α 2 is greater than-30 degrees (minus 30 degrees) and 30 degrees or less.

A third included angle Ψ 1 between the second line L2 and the eighth line L8 is greater than 0 degree and equal to or less than 15 degrees, and a fourth included angle Ψ 2 between the fifth line L5 and the eighth line L8 is greater than 0 degree and equal to or less than 15 degrees (as shown in fig. 3). That is, in a front view, i.e., when the second plane is viewed in a direction adjacent to at least one of the first and

second workpieces

110 and 120, the third angle Ψ 1 is greater than 0 degrees and 15 degrees or less, and the fourth angle Ψ 2 is greater than 0 degrees and 15 degrees or less.

A fifth included angle β 1 between the third line L3 and the ninth line L9 is greater than or equal to-15 degrees (minus 15 degrees) and less than 0 degree, and a sixth included angle β 2 between the sixth line L6 and the ninth line L9 is greater than 0 degree and less than or equal to 15 degrees (as shown in fig. 4). That is, in a plan view, that is, when the third plane is viewed downward, the fifth angle β 1 is equal to or greater than-15 degrees (minus 15 degrees) and less than 0 degree, and the sixth angle β 2 is equal to or greater than 0 degree and equal to or less than 15 degrees.

The first angle α 1 between the first straight line L1 and the fourth straight line L4 is taken as an example, and the meaning of the angle having a positive value and a negative value will be described.

The positive value of the first included angle α 1 between the first straight line L1 and the fourth straight line L4 means that: the fourth straight line L4 is located downstream of the first straight line L1 in the clockwise direction, i.e. when the first straight line L1 rotates in the clockwise direction by the first included angle α 1, the first straight line L1 coincides with the fourth straight line L4.

The negative value of the first included angle α 1 between the first straight line L1 and the fourth straight line L4 means that: the fourth straight line L4 is located downstream of the first straight line L1 in the counterclockwise direction, that is, when the first straight line L1 rotates in the counterclockwise direction by the first included angle α 1, the first straight line L1 coincides with the fourth straight line L4.

Wherein the transverse welding may include: and welding a horizontal welding seam on a vertical plane of the workpiece to be welded and welding a horizontal welding seam on an inclined plane of the workpiece to be welded.

According to the transverse welding method provided by the embodiment of the invention, by setting the angles (the first included angle alpha 1 to the sixth included angle beta 2) of the front heat source 130 and the rear heat source 140 in the three-dimensional space, not only can the penetration force of the front heat source 130 be prevented from being too strong and too weak so as to continuously create the grooves 151 and the through holes 152, but also the rear heat source 140 can be prevented from being filled with too much and too little liquid metal, so that the liquid metal generated by the rear heat source 140 smoothly enters the back of the weld through the grooves 151 and the through holes 152 created by the front heat source 130 before solidification, and fills the space formed by the grooves 151 and the through holes 152, and the cladding property and the wettability of the back metal can be adjusted, and the microstructure and the macro topography of the weld are optimized. Therefore, the welding defects can be further eliminated, and the welding quality is further improved.

Specifically, if the penetrating power of the front heat source 130 is too strong and the rear heat source 140 is filled with too much liquid metal, the metal on the back surfaces of the first and

second workpieces

110 and 120 is excessively penetrated, and even welding leakage is caused. If the penetrating power of the front heat source 130 is too strong and the rear heat source 140 is filled with too little liquid metal, the defects of incomplete welding, undercut, and the like exist on the front surfaces of the first workpiece 110 and the second workpiece 120.

If the penetrating power of the front heat source 130 is too weak, it causes a defect that the back surfaces of the first and

second workpieces

110 and 120 are not welded through. If the penetrating power of the front heat source 130 is too weak and the filling of the rear heat source 140 is too much, the via holes 152 cannot be formed in the first workpiece 110 and the second workpiece 120, resulting in the defects of incomplete back surface welding, flow on the front surface, flash, too high residual height, asymmetric welding seam and the like.

As shown in fig. 1 and 2, the first and

second workpieces

110 and 120 may be obliquely disposed when performing the transverse welding. A seventh angle between each of the welding surface of the first workpiece 110 and the welding surface of the second workpiece 120 and the vertical line may be 0 degrees or more and 30 degrees or less. Preferably, the seventh angle may be greater than 0 degrees and equal to or less than 30 degrees.

Specifically, when each of the first and

second workpieces

110 and 120 has a flat plate shape, a seventh angle between each of the first and

second workpieces

110 and 120 and the vertical line may be 0 degrees or more and 30 degrees or less. When the first and

second workpieces

110, 120 form the box-shaped member 170, the front and

rear heat sources

130, 140 act on the flat plate portion of the first workpiece 110 and the flat plate portion of the second workpiece 120. A seventh angle between each of the flat plate portion of the first workpiece 110 and the flat plate portion of the second workpiece 120 and the vertical line may be greater than or equal to 0 degree and less than or equal to 30 degrees.

That is, when the first workpiece 110 and the second workpiece 120 constitute the box-shaped member 170, an angle θ between a bottom surface of a workpiece (e.g., the first workpiece 110 in fig. 1) located below and a horizontal plane may be greater than 0 degree and equal to or less than 30 degrees.

Since the angles of the front heat source 130 and the rear heat source 140 in the three-dimensional space are related to the penetration force of the front heat source 130 and the amount of liquid metal filled in the rear heat source 140, the first included angle α 1 to the sixth included angle β 2 are preferably related to the seventh included angle. Wherein, the angle of the via hole 152 created by the front heat source 130 in the three-dimensional space may be the same as the angle of the front heat source 130 in the three-dimensional space.

Specifically, each of the first included angle α 1, the second included angle α 2, the third included angle Ψ 1, and the fourth included angle Ψ 2 may decrease as the seventh included angle increases, and each of the fifth included angle β 1 and the sixth included angle β 2 may increase as the seventh included angle increases. Further, each of the third angle Ψ 1, the fourth angle Ψ 2, the fifth angle β 1, and the sixth angle β 2 may decrease as at least one of the current of the front heat source 130 and the current of the rear heat source 140 increases.

Preferably, the first included angle α 1 may be greater than or equal to 5 degrees and less than or equal to 10 degrees, the second included angle α 2 may be greater than or equal to 10 degrees and less than or equal to 20 degrees or greater than or equal to-20 degrees and less than or equal to-10 degrees, each of the third included angle Ψ 1 and the fourth included angle Ψ 2 may be greater than or equal to 5 degrees and less than or equal to 10 degrees, the fifth included angle β 1 may be greater than or equal to-10 degrees and less than or equal to-5 degrees, the sixth included angle β 2 may be greater than or equal to 5 degrees and less than or equal to 10 degrees, and the seventh included angle may be greater than or equal to 10 degrees and less than or equal to 20 degrees.

Furthermore, other parameters of the transverse welding method according to embodiments of the invention are preferably also relevant. Specifically, the welding speed may be increased as at least one of the current of the front heat source 130 and the current of the rear heat source 140 is increased. It is possible to prevent the penetrating power of the front heat source 130 from being excessively strong and to prevent the rear heat source 140 from being excessively filled with the liquid metal.

Preferably, the welding speed may be 600 mm to 1800 mm/min. Further preferably, the welding speed may be 800 mm to 1500 mm/min. More preferably, the welding speed may be 1000 mm-1300 mm/min. Most preferably, the welding speed may be 1100 mm-1200 mm/min.

The center distance d of the front heat source 130 and the rear heat source 140 may increase as at least one of the current of the front heat source 130 and the current of the rear heat source 140 increases. This prevents excessive heat from being applied per unit area, thereby preventing back surface leakage. The center distance d between the front heat source 130 and the rear heat source 140 is: the distance between the first end of the front heat source 130 and the first end of the rear heat source 140 in the length direction of the weld. The first end of the front heat source 130 is the end of the front heat source 130 adjacent to the first and

second workpieces

110, 120, and the first end of the rear heat source 140 is the end of the rear heat source 140 adjacent to the first and

second workpieces

110, 120.

Preferably, the center distance d between the front heat source 130 and the rear heat source 140 may be 5 mm to 10 mm. Further preferably, the center distance d between the front heat source 130 and the rear heat source 140 may be 6 mm to 9 mm. More preferably, the center distance d between the front heat source 130 and the rear heat source 140 may be 7.5 mm.

The current of the front heat source 130 decreases as the vertical distance h of the front heat source 130 from the first and

second workpieces

110 and 120 decreases, and each of the current of the rear heat source 140 and the voltage of the rear heat source 140 decreases as the vertical distance h of the rear heat source 140 from the first and

second workpieces

110 and 120 decreases. It is possible to prevent the penetrating power of the front heat source 130 from being excessively strong and to prevent the rear heat source 140 from being excessively filled with the liquid metal.

Wherein, when the front surface of the first workpiece 110 is flush with the front surface of the second workpiece 120, the vertical distance h between the front heat source 130 and the first and

second workpieces

110 and 120 refers to the vertical distance between the first end of the front heat source 130 and any one of the front surfaces of the first and

second workpieces

110 and 120, and the vertical distance h between the rear heat source 140 and the first and

second workpieces

110 and 120 refers to the vertical distance between the first end of the rear heat source 140 and any one of the front surfaces of the first and

second workpieces

110 and 120.

When the front surface of the first workpiece 110 is not flush with the front surface portion of the second workpiece 120, i.e., the thickness of the first workpiece 110 is not equal to the thickness of the second workpiece 120, the vertical distance h between the front heat source 130 and the first and

second workpieces

110 and 120 refers to the vertical distance between the first end of the front heat source 130 and the front surface of the thinner one of the first and

second workpieces

110 and 120.

The first end of the front heat source 130 is the end of the front heat source 130 adjacent to the first and

second workpieces

110, 120.

Preferably, the vertical distance h between the front heat source 130 and the first and

second workpieces

110 and 120 may be 3 mm to 8 mm, and the vertical distance h between the rear heat source 140 and the first and

second workpieces

110 and 120 may be 3 mm to 8 mm.

Further preferably, the vertical distance h between the front heat source 130 and the first and

second workpieces

110 and 120 may be 4 mm to 7 mm, and the vertical distance h between the rear heat source 140 and the first and

second workpieces

110 and 120 may be 4 mm to 7 mm.

More preferably, the vertical distance h between the front heat source 130 and the first and

second workpieces

110 and 120 may be 5.5 mm, and the vertical distance h between the rear heat source 140 and the first and

second workpieces

110 and 120 may be 5.5 mm.

Most preferably, the vertical distance h between the front heat source 130 and the first and

second workpieces

110 and 120 may be equal to the vertical distance h between the rear heat source 140 and the first and

second workpieces

110 and 120.

A magnetic field may be provided between the front heat source 130 and the rear heat source 140. By providing a magnetic field between the front heat source 130 and the rear heat source 140, it is possible to prevent interference between the arc of the front heat source 130 and the arc of the rear heat source 140, and to adjust the arc shape of the front heat source 130 and the arc shape of the rear heat source 140. Preferably, the magnetic field may be located adjacent to a first end of the front heat source 130 and a first end of the rear heat source 140.

Each of the current of the front heat source 130, the current of the rear heat source 140, the voltage of the rear heat source 140, the flow rate of the shield gas of the rear heat source 140, the flow rate of the plasma gas (i.e., the front heat source 130 is a plasma beam), and the strength of the magnetic field increases as at least one of the thickness of the first workpiece 110 and the thickness of the second workpiece 120 increases. This not only allows the front heat source 130 to have sufficient penetrating power, but also allows the rear heat source 140 to be filled with an appropriate amount of liquid metal.

Wherein, the prepositive heat source 130 and the postpositive heat source 140 can act on the center of the welding seam, and the acting area of the prepositive heat source 130 can be smaller than that of the postpositive heat source 140. Since the active area of the front heat source 130 is small, the front heat source 130 can generate the via hole 152 with a predetermined width without causing the defect of back surface solder leakage.

The front heat source 130 may be an electron beam, a laser beam, or a plasma beam, the rear heat source 140 may be an arc, and the shielding gas of the rear heat source 140 may be at least one selected from the group consisting of argon, argon-rich gas, carbon dioxide gas, nitrogen gas, and helium gas. The current of the front heat source 130 may be 80 to 160 amperes, the current of the rear heat source 140 may be 310 to 400 amperes, the voltage of the rear heat source 140 may be 18 to 24 volts, and the flow rate of the shielding gas of the rear heat source 140 may be 10 to 25 liters/minute.

Preferably, the current of the front heat source 130 may be 100 to 140 amperes, the current of the rear heat source 140 may be 345 to 365 amperes, the voltage of the rear heat source 140 may be 20.5 to 22 volts, and the flow rate of the shielding gas of the rear heat source 140 may be 15 to 20 liters/minute.

More preferably, the current of the front heat source 130 may be 110 to 130 amperes, the current of the rear heat source 140 may be 350 to 360 amperes, the voltage of the rear heat source 140 may be 21 to 21.5 volts, and the flow rate of the shielding gas of the rear heat source 140 may be 17.5 liters/minute.

Most preferably, the current of the front heat source 130 may be 120 amperes, the current of the rear heat source 140 may be 355 amperes, and the voltage of the rear heat source 140 may be 21.25 volts.

The preheat source 130 may be a plasma beam and the plasma gas flow rate of the preheat source 130 may be 4 liters/minute to 8 liters/minute. Preferably, the plasma gas flow rate of the preheat source 130 may be 5.5 liters/minute to 7.5 liters/minute. More preferably, the plasma gas flow rate of the preheat source 130 may be 6 liters/minute to 7 liters/minute. Most preferably, the plasma gas flow rate of the preheat source 130 may be 6.5 liters/minute.

The gap (pair-wise distance) between the first workpiece 110 and the second workpiece 120 may be 2 mm or less. Preferably, the gap between the first workpiece 110 and the second workpiece 120 may be less than or equal to 1 mm. More preferably, the gap between the first workpiece 110 and the second workpiece 120 may be 0.5 mm or less. Most preferably, the gap between the first workpiece 110 and the second workpiece 120 is equal to 0 mm so that the first workpiece 110 is in contact with the second workpiece 120.

Because the front heat source 130 may continuously create the bevel 151, the cross welding method according to embodiments of the present invention does not require bevels on the first and

second workpieces

110, 120. Therefore, the gap between the first workpiece 110 and the second workpiece 120 can be greatly reduced, the difficulty of positioning and clamping the first workpiece 110 and the second workpiece 120 can be reduced, and the welding difficulty is further reduced. When the first workpiece 110 contacts the second workpiece 120, the first workpiece 110 and the second workpiece 120 are positioned and clamped with the least difficulty.

Further, the smaller the gap between the first workpiece 110 and the second workpiece 120, the smaller the cross-sectional area of the weld 160 (the area of the cross-section perpendicular to the longitudinal direction of the weld), and the smaller the welding material consumption, welding deformation, and residual stress.

Although the transverse welding method according to the embodiment of the present invention does not require the beveling of the first and

second workpieces

110 and 120, it does not mean that the beveling of the first and

second workpieces

110 and 120 cannot be performed. Particularly when the thickness of the first workpiece 110 and the thickness of the second workpiece 120 are both greater than 8 mm, bevels may be machined on the first workpiece 110 and the second workpiece 120 in order to make it easier for the front heat source 130 to create the via 152.

Specifically, an I-groove, a V-groove, a single-sided V-groove, a Y-groove, or a U-groove may be provided between the first workpiece 110 and the second workpiece 120. Preferably, a V-groove, a single V-groove, or a Y-groove may be provided between the first workpiece 110 and the second workpiece 120, and a groove angle of each of the V-groove, the single V-groove, and the Y-groove may be greater than 0 degree and equal to or less than 30 degrees.

More preferably, the groove angle of each of the V-groove, the single-sided V-groove, and the Y-groove may be 10 degrees or more and 20 degrees or less, and the blunt edge may be 6 mm or less. Most preferably, the bevel angle of each of the V-groove, the single-sided V-groove, and the Y-groove may be equal to 15 degrees, and the blunt side may be equal to or less than 5 mm.

In one specific example of the present invention, the first workpiece 110 and the second workpiece 120 may be manufactured by using a plasma cutting method, and the first workpiece 110 and the second workpiece 120 may have an I-shaped bevel therebetween. That is, a bevel need not be machined between the first workpiece 110 and the second workpiece 120.

In the conventional transverse welding method, since the plasma cut surface (surface to be welded) of the workpiece has a large roughness, it is necessary to bevel the plasma cut surface of the workpiece. That is, the conventional technique cannot weld a workpiece manufactured by the plasma cutting method in the transverse direction without machining the groove.

According to the transverse welding method provided by the embodiment of the invention, the workpiece manufactured by using the plasma cutting mode can be directly transversely welded without processing a groove, so that the requirement on the workpiece can be reduced, and the selection range of the workpiece is expanded.

By selecting the value range of the parameters, the viscosity and the flow characteristic of the molten metal (liquid metal) can be changed so as to change the shape of a molten pool, and the liquid metal can be further ensured not to flow to the back of the welding line too much, and the problems of front collapse, back welding leakage and the like can be avoided.

In one example of the present invention, the first workpiece 110 and the second workpiece 120 may constitute a box-shaped member 170, the box-shaped member 170 may have at least two welding seams 160, and the at least two welding seams 160 may be welded simultaneously.

If at least two welds 160 of the box 170 are welded in series, the welded box 170 is susceptible to distortion. By simultaneously welding at least two welding seams 160 of the box member 170, the box member 170 can be effectively prevented from being distorted.

The invention also provides a weldment 10. As shown in fig. 1 and 6, a weldment 10 according to an embodiment of the present invention includes a first workpiece 110 and a second workpiece 120, the first workpiece 110 and the second workpiece 120 being joined by a weld 160, the weld 160 having, in a thickness direction of the weld 160, a first crystallographic direction and a second crystallographic direction opposite the first crystallographic direction. Wherein the first crystallographic direction is shown by arrow B in fig. 6, the second crystallographic direction is shown by arrow C in fig. 6, and the thickness direction of the weld 160 is shown by arrow D in fig. 6.

Since the weld 160 has the first crystal direction and the second crystal direction opposite to the first crystal direction in the thickness direction thereof, both the front and back sides of the weld 160 are sufficiently and uniformly heated, and the heat conduction during the crystallization of the weld 160 is typically a two-dimensional planar conduction, so that the internal crystal form of the weld 160 can be more symmetrical and uniform, the probability of generating defects in the weld 160 is lower, the quality of the weld 160 is higher, and the back side does not need to be subjected to repair welding to eliminate the defects, and the weld 160 with good and uniform front and back molding can be obtained without back side back gouging or back side repair welding.

Therefore, the welding part 10 provided by the embodiment of the invention has the advantages of high welding efficiency, good welding quality, low welding difficulty, stable structure, high strength and the like.

The thickness direction of each of the first and

second workpieces

According to the embodiment of the invention, the molding volumes of the front surface and the back surface of the welding seam 160 of the welding part 10 are closer, and the front surface and the back surface of the welding seam 160 are more uniform and full, so that the stress concentration degree of the welding seam 160 can be reduced. Therefore, the weldment 10 according to the embodiment of the invention has the advantage of low stress concentration.

Further preferably, the coefficient of the face-back residual height of the weld 160 may be greater than 1 and 2.5 or less. More preferably, the coefficient of the face-back residual height of the weld 160 may be greater than 1 and equal to or less than 2. Most preferably, the face-to-back coefficient of the weld 160 may be greater than 1 and equal to or less than 1.6. Therefore, the molding volumes of the front surface and the back surface of the welding seam 160 of the welding part 10 according to the embodiment of the invention are closer, and the front surface and the back surface of the welding seam 160 are more uniform and full, so that the stress concentration degree of the welding seam 160 can be further reduced.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A transverse welding method, comprising the steps of:

positioning a first workpiece and a second workpiece to be welded to enable surfaces to be welded to be in a transverse welding position;

providing a front heat source and a rear heat source, enabling the to-be-welded positions of the to-be-welded surfaces of the first workpiece and the second workpiece to form a welding seam, wherein the energy density of the front heat source is larger than that of the rear heat source, the front heat source continuously creates a groove and a through hole at the to-be-welded positions, the front heat source and the rear heat source enable a molten pool to flow in a controlled mode, one part of the molten pool enters the back surface of the first workpiece and the back surface of the second workpiece through the groove and the through hole, and the other part of the molten pool is filled in the groove and the through hole, so that heat conduction during welding seam crystallization is two-dimensional plane conduction, and the welding seam has a first crystallization direction and a second crystallization direction opposite to the first crystallization direction in the thickness direction of the welding seam;

the preposed heat source and the postpositional heat source redistribute the gravity, the arc thrust, the electromagnetic force and the surface tension of the molten pool to ensure that the molten pool performs controlled flow, so that the welding seam has a symmetrical plane of the crystal direction, and the first crystal direction and the second crystal direction are symmetrical relative to the symmetrical plane of the crystal direction in the thickness direction of the welding seam; the thickness direction of each of the first and second workpieces coincides with the thickness direction of the weld, the thickness of the first workpiece is greater than the thickness of the second workpiece, wherein the crystallographic direction symmetry plane is parallel to a thickness center plane of the first workpiece, and the distance between the crystallographic direction symmetry plane and the thickness center plane of the first workpiece is less than or equal to 1/5 of the thickness of the first workpiece.

2. The transverse welding method of claim 1, wherein a distance between the crystallographic-direction symmetry plane and a thickness center plane of the first workpiece is less than or equal to 1/6 of the thickness of the first workpiece.

3. The transverse welding method according to any one of claims 1 to 2, characterized in that a face-back coefficient of residual height of the weld is greater than 1 and equal to or less than 3.

4. The transverse welding method according to claim 3, wherein a coefficient of the face-back residual height of the weld is greater than 1 and 1.6 or less.

5. The lateral welding method of any of claims 1-2, wherein the via has a width of 0.5-3 mm.

6. The transverse welding method according to any one of claims 1-2, wherein the first workpiece and the second workpiece constitute a box-shaped member having at least one of the weld seams, and when the number of the weld seams is 2 or more, at least two of the weld seams are welded simultaneously.

7. A weldment made using the transverse welding method of any one of claims 1 to 6, comprising: a first workpiece and a second workpiece connected by a weld, the weld having, in a thickness direction of the weld, a first crystallographic direction and a second crystallographic direction opposite the first crystallographic direction; the weld joint has a crystal direction symmetry plane, and the first crystal direction and the second crystal direction are symmetrical relative to the crystal direction symmetry plane in the thickness direction of the weld joint; the thickness direction of each of the first and second workpieces coincides with the thickness direction of the weld, the thickness of the first workpiece is greater than the thickness of the second workpiece, wherein the crystallographic direction symmetry plane is parallel to a thickness center plane of the first workpiece, and the distance between the crystallographic direction symmetry plane and the thickness center plane of the first workpiece is less than or equal to 1/5 of the thickness of the first workpiece.

8. The weldment of claim 7, wherein the distance between the crystallographic-direction symmetry plane and the thickness center plane of the first workpiece is less than or equal to 1/6 for the thickness of the first workpiece.

9. The weldment of any of claims 7 to 8, wherein the face-to-back coefficient of run-out of the weld is greater than 1 and equal to or less than 3.

10. The weldment of claim 9, wherein the face-to-back coefficient of run-on height of the weld is greater than 1 and equal to or less than 1.6.