阅读说明：本技术 不锈钢复合器件及其焊接方法 (Stainless steel composite device and welding method thereof ) 是由 唐连科 胡陈 于 2019-02-22 设计创作，主要内容包括：本发明提供了一种不锈钢复合器件及其焊接方法。该不锈钢复合器件包括：两个不锈钢复合构件,各不锈钢复合构件均包括对应焊接的基层和覆层,基层为低碳钢层,覆层为不锈钢；焊缝,将两个不锈钢复合构件焊接,焊接的钝边设置在基层内且根部无间隙,焊缝包括第一焊缝,第一焊缝设置在覆层侧,第一焊缝具有第一焊缝坡口,第一焊缝坡口包括两个坡口面,各不锈钢复合构件均设置有一个坡口面,其中一个坡口面包括：下坡口面,设置在基层中；连接坡口面,设置在基层内,连接坡口面与下坡口面的夹角大于等于120°小于180°；上坡口面,上坡口面与下坡口面通过连接坡口面连接且由基层延伸至覆层。解决了不锈钢复合坩埚的封头与筒体焊缝易开裂的问题。(The invention provides a stainless steel composite device and a welding method thereof. The stainless steel composite device includes: the stainless steel composite member comprises a base layer and a coating layer which are correspondingly welded, wherein the base layer is a low-carbon steel layer, and the coating layer is stainless steel; the welding seam, with two stainless steel composite member welding, welded truncated edge sets up in the basic unit and root zero clearance, and the welding seam includes first welding seam, and first welding seam setting is on the covering layer side, and first welding seam has first welding seam groove, and first welding seam groove includes two bevel face, and each stainless steel composite member all is provided with a bevel face, and one of them bevel face includes: a downhill slope surface disposed in the base layer; the connection bevel face is arranged in the base layer, and the included angle between the connection bevel face and the downhill bevel face is more than or equal to 120 degrees and less than 180 degrees; the upper bevel face is connected with the lower bevel face through the connecting bevel face and extends from the base layer to the coating layer. The problem that the welding seam of the end socket and the cylinder body of the stainless steel composite crucible is easy to crack is solved.)

1. A stainless steel composite device, comprising:

the composite structure comprises two stainless steel composite components (10), wherein each stainless steel composite component (10) comprises a base layer (11) and a coating layer (12) which are correspondingly welded, the base layer (11) is a low-carbon steel layer, and the coating layer (12) is stainless steel;

a weld seam welding the two stainless steel composite members (10), the welded blunt edge being disposed in the base layer (11) with no gap at the root, the weld seam comprising a first weld seam (31 '), the first weld seam (31 ') being disposed on the cladding (12) side, the first weld seam (31 ') having a first weld seam groove (31), the first weld seam groove (31) comprising two bevel faces, each of the stainless steel composite members (10) being provided with one of the bevel faces, one of the bevel faces comprising:

a lower notch surface (311) provided in the base layer (11);

the connection bevel face (312) is arranged in the base layer (11), and the included angle between the connection bevel face (312) and the downhill bevel face (311) is more than or equal to 120 degrees and less than 180 degrees;

an upper bevel surface (313), the upper bevel surface (313) and the lower bevel surface (311) are connected through the connecting bevel surface (312) and extend from the base layer (11) to the coating (12).

2. The stainless steel composite component according to claim 1, characterized in that the connection between the upper bevel surface (313) and the connection bevel surface (312) and/or the connection between the lower bevel surface (311) and the connection bevel surface (312) has a rounded chamfer, preferably with a radius R of 1-3 mm.

3. The stainless steel composite component according to claim 2, wherein the connection bevel face (312) extends 3-8 mm in length, preferably the connection bevel face (312) is parallel to the connection face of the base layer (11) and the cover layer (12), preferably the angle of the upper bevel face (313) is the same as the angle of the lower bevel face (311).

4. The stainless steel composite device according to claim 1, wherein the width of the blunt edge is 3 to 8mm, preferably the thickness of the base layer (11) is 25 to 35mm, more preferably the thickness of the cover layer (12) is 4 to 8 mm.

5. The stainless steel composite device according to claim 1, wherein the upper bevel face (313) and the lower bevel face (311) are each independently a V-or U-shaped bevel face, preferably the other bevel face of the first weld groove (31) is a V-or U-shaped bevel face.

6. The stainless steel composite component according to claim 1, wherein the weld further comprises a second weld (32 '), the second weld (32 ') being disposed on the base layer (11) side of the two stainless steel composite members (10), the second weld (32 ') having a second weld groove (32), the second weld groove (32) being a V-groove or a U-groove, the second weld groove (32) being disposed within the base layer (11), preferably the second weld groove (32) having a depth of 12-18 mm.

7. The stainless steel composite device according to claim 1, wherein the first weld (31') comprises:

the base layer welding seam (311') is arranged in the first welding seam groove (31) corresponding to the lower notch surface (311);

a transition layer weld (312 ') extending from the surface of the base layer weld (311') into the first weld groove (31) corresponding to the upper bevel face (313);

a cladding weld (313 ') disposed on a surface of the transition layer weld (312') and having a residual height protruding from the surface of the cladding (12), preferably the residual height is 2mm or less.

8. The stainless steel composite device according to claim 7, characterized in that the base layer weld (311 '), the transition layer weld (312') and the cladding weld (313 ') are of different materials, preferably the base layer weld (311') comprises a carbon steel high manganese submerged arc welding wire; preferably, the welding material of the transition layer welding seam (312') comprises a nickel alloy welding rod; preferably, the welding material of the clad weld (313') comprises a stainless steel welding rod.

9. The stainless steel composite component according to claim 7, characterized in that the thickness of the transition layer weld (312 ') is 3-6 mm, preferably the thickness of the transition layer weld (312 ') corresponding to the base layer (11) is 1.5-3 mm, preferably the thickness of the transition layer weld (312 ') corresponding to the cladding layer (12) is 1.5-3 mm.

10. The stainless steel composite device according to any one of claims 1 to 9, wherein the stainless steel composite device is a stainless steel composite crucible, the stainless steel composite member (10) having the connection bevel face (312) is a cylinder (2), the other stainless steel composite member (10) is a seal head (1), preferably, one end of the seal head (1) welded to the cylinder (2) is a straight edge end, and further preferably, the straight edge length of the straight edge end is 60-70 mm.

11. The stainless steel composite device of claim 10, wherein the stainless steel composite crucible further comprises:

the supporting plate (3) is close to one end, far away from the seal head (1), of the cylinder body (2), and is welded with the outer wall of the cylinder body (2);

the reinforcing plates (4) are arranged on one side of the supporting plate (3) far away from the seal head (1) and along the circumferential direction of the barrel body (2), the reinforcing plates (4) are welded with the supporting plate (3) and the barrel body (2), and hoisting holes are formed in the reinforcing plates (4) preferably.

12. A method of welding the stainless steel composite components of any one of claims 1 to 11, characterized in that the welding method comprises:

step S1 of machining a first weld groove (31) of the stainless steel composite device according to any one of claims 1 to 11 on two stainless steel composite members (10);

step S2, aligning the base layer (11) and aligning the cladding layer (12) and the cladding layer (12) of the two stainless steel composite components (10);

step S3, starting first welding from the root of the first weld groove (31) by using a first welding material, and after the welding of the position of the downward notch surface (311) of the first weld groove (31) corresponding to the groove is completed, replacing the first welding material with a second welding material to weld to a certain position in the corresponding cladding (12) for the second time; and replacing the second welding material with a third welding material, and welding the second welding material to the welding seam groove for the third time.

13. The welding method of claim 12, wherein the weld further comprises a second weld (32'), the step S1 further comprises machining a second weld groove (32) on two stainless steel composite members (10), and the step S3 further comprises a process of performing a fourth weld from a root of the second weld groove (32) with the first weld material.

14. The welding method according to claim 12, further comprising, after the step S3, performing a heat treatment on the welded part, wherein the heat treatment comprises heat preservation at 500 to 550 ℃ for 3 to 5 hours.

15. The welding method according to claim 13, wherein the first welding and the fourth welding are submerged arc welding, the first welding material comprises a carbon steel high manganese submerged arc welding wire and a flux, the current of each of the first welding and the fourth welding is 450 to 500A, the arc voltage is 30 to 35V, and the speed is 40 to 45cm/min, preferably the diameter of the carbon steel high manganese submerged arc welding wire is 3 to 5mm, and the thickness of the seam welding line of the submerged arc welding is smaller than the diameter of the carbon steel high manganese welding wire.

16. The welding method of claim 12, wherein said second weld is a manual weld, said second welding material comprises a nickel alloy electrode, preferably said nickel alloy electrode has a diameter of 3-5 mm; preferably, the third welding is manual welding, the third welding material comprises a stainless steel welding rod, the diameter of the stainless steel welding rod is 3-5 mm, the current of the second welding and the current of the third welding are 120-140A respectively, the arc voltage of the second welding and the arc voltage of the third welding are 18-25V respectively, and the speed of the second welding and the third welding are 10-15 cm/min respectively.

17. The welding method according to claim 12, characterized in that between the step S1 and the step S3, the welding method further comprises a process of cleaning a region of the stainless steel composite member (10) within 25mm from a root of the first weld groove (31) to remove impurities.

Technical Field

The invention relates to the technical field of welding, in particular to a stainless steel composite device and a welding method thereof.

Background

The stainless steel composite crucible has the characteristics of good corrosion resistance and strong high-temperature oxidation resistance, and is commonly used for casting magnesium alloy. At present, a commonly used stainless steel composite crucible is generally formed by welding a cylinder body and an end enclosure to form a main body structure.

The cylinder and the end enclosure of a common stainless steel composite crucible are of a double-layer structure, the inner layer is low-carbon alloy steel, and the outer layer is stainless steel, but after a connecting welding seam of the end enclosure and the cylinder of the stainless steel composite crucible manufactured at present is used for a period of time, the welding seam cracks along a side heat affected zone of the cylinder, so that the crucible is frequently repaired, the service life is short, and the production cost of products such as magnesium alloy is high.

Disclosure of Invention

The invention mainly aims to provide a stainless steel composite device and a welding method thereof, and aims to solve the problem that welding seams of a sealing head and a cylinder body of a stainless steel composite crucible in the prior art are easy to crack.

In order to achieve the above object, according to one aspect of the present invention, there is provided a stainless steel composite device including: the stainless steel composite member comprises a base layer and a coating layer which are correspondingly welded, wherein the base layer is a low-carbon steel layer, and the coating layer is stainless steel; the welding seam, with two stainless steel composite member welding, welded truncated edge sets up in the basic unit and root zero clearance, and the welding seam includes first welding seam, and first welding seam setting is on the covering layer side, and first welding seam has first welding seam groove, and first welding seam groove includes two bevel face, and each stainless steel composite member all is provided with a bevel face, and one of them bevel face includes: a downhill slope surface disposed in the base layer; the connection bevel face is arranged in the base layer, and the included angle between the connection bevel face and the downhill bevel face is more than or equal to 120 degrees and less than 180 degrees; the upper bevel face is connected with the lower bevel face through the connecting bevel face and extends from the base layer to the coating layer.

Furthermore, the joint between the upper bevel face and the connecting bevel face and/or the joint between the lower bevel face and the connecting bevel face is provided with a round chamfer, and the radius R of the round chamfer is preferably 1-3 mm.

Furthermore, the extension length of the connection bevel face is 3-8 mm, the connection bevel face is preferably parallel to the connection face of the base layer and the coating layer, and the angle of the upper bevel face is preferably the same as that of the lower bevel face.

Further, the width of the truncated edge is 3 to 8mm, the thickness of the base layer is preferably 25 to 35mm, and the thickness of the coating layer is more preferably 4 to 8 mm.

Further, the upper groove surface and the lower groove surface are each independently a V-groove surface or a U-groove surface, and preferably, the other groove surface of the first weld groove is a V-groove surface or a U-groove surface.

Further, the welding seam further comprises a second welding seam, the second welding seam is arranged on the side of the base layer of the two stainless steel composite members, the second welding seam is provided with a second welding seam groove, the second welding seam groove is a V-shaped groove or a U-shaped groove, the second welding seam groove is arranged in the base layer, and the depth of the second welding seam groove is preferably 12-18 mm.

Further, the first weld includes: the base layer welding seam is arranged in the first welding seam groove corresponding to the downward bevel face; the transition layer welding seam extends from the surface of the base layer welding seam to the first welding seam groove corresponding to the upper bevel face; and the cladding welding seam is arranged on the surface of the transition layer welding seam and is provided with a residual height part protruding out of the surface of the cladding, and the height of the residual height part is preferably less than or equal to 2 mm.

Furthermore, the welding materials of the base layer welding seam, the transition layer welding seam and the coating layer welding seam are different, and preferably, the welding material of the base layer welding seam comprises a carbon steel high-manganese submerged arc welding wire; preferably, the welding material of the transition layer welding seam comprises a nickel alloy welding rod; preferably, the welding material of the clad weld comprises a stainless steel welding rod.

Further, the thickness of the transition layer welding seam is 3-6 mm, the thickness of the transition layer welding seam corresponding to the base layer is preferably 1.5-3 mm, and the thickness of the transition layer welding seam corresponding to the coating layer is preferably 1.5-3 mm.

Further, the stainless steel composite device is a stainless steel composite crucible, the stainless steel composite component with the connection bevel face is a cylinder, the other stainless steel composite component is an end socket, preferably, one end of the end socket welded with the cylinder is a straight edge end, and further preferably, the straight edge length of the straight edge end is 60-70 mm.

Further, the stainless steel composite crucible further comprises: the supporting plate is close to one end, far away from the end socket, of the barrel and is welded with the outer wall of the barrel; a plurality of stiffening plates, the setting just follows barrel circumference evenly distributed in one side of keeping away from the head in the backup pad, and the stiffening plate is provided with the hole for hoist on preferred each stiffening plate with backup pad and barrel welding.

According to another aspect of the present invention, there is provided a welding method of the stainless steel composite device of any one of the above, the welding method comprising: step S1, processing a first weld groove of any one of the stainless steel composite devices on two stainless steel composite components; step S2, aligning the base layer and the cladding layer of the two stainless steel composite components; step S3, using a first welding material to start first welding from the root of the first welding seam groove, and after the welding of the position of the downward notch surface of the first welding seam groove corresponding to the groove is finished, replacing the first welding material with a second welding material to weld to a certain position in the corresponding coating for the second time; and replacing the second welding material with a third welding material, and carrying out third welding till the welding of the welding seam groove is completed.

Further, the welding seam further comprises a second welding seam, the step S1 further comprises processing a second welding seam groove on the two stainless steel composite components, and the step S3 further comprises a process of performing fourth welding from the root of the second welding seam groove by using the first welding material.

Further, after the step S3, the welding method further includes performing heat treatment on the welded part, where the heat treatment includes heat preservation at 500-550 ℃ for 3-5 hours.

Further, the first welding and the fourth welding are submerged-arc welding, the first welding material comprises a carbon steel high-manganese submerged-arc welding wire and a welding flux, the current of the first welding and the fourth welding is 450-500A respectively, the arc voltage is 30-35V respectively, the speed is 40-45 cm/min respectively, the diameter of the carbon steel high-manganese submerged-arc welding wire is preferably 3-5 mm, and the thickness of a seam welding seam of the submerged-arc welding is smaller than that of the carbon steel high-manganese welding wire.

Further, the second welding is manual welding, the second welding material comprises a nickel alloy welding rod, and the diameter of the nickel alloy welding rod is preferably 3-5 mm; preferably, the third welding is manual welding, the third welding material comprises a stainless steel welding rod, the diameter of the stainless steel welding rod is 3-5 mm, the current of the second welding and the current of the third welding are 120-140A respectively, the arc voltage of the second welding and the arc voltage of the third welding are 18-25V respectively, and the speed of the second welding and the third welding are 10-15 cm/min respectively.

Further, between the above step S1 and step S3, the welding method further includes a process of cleaning a region of the stainless steel composite member within 25mm from the root of the first weld groove to remove impurities.

By applying the technical scheme of the invention, the upper bevel face and the lower bevel face of one bevel face of the first weld groove of the weld are connected through the connecting bevel face and extend from the base layer to the coating layer, so that the weld is increased relative to the bevel face in the prior art on the basis of not increasing the angle of the groove, the volume of the first weld arranged in the groove is further increased, when the welding method is applied to a stainless steel composite crucible, the position of a fusion line of the first weld avoids a region with serious heat influence, the cracking of the first weld is further effectively relieved, and the service life of the stainless steel composite crucible is further prolonged.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram illustrating a groove structure of two stainless steel composite members after butt joint according to an embodiment of the invention;

FIG. 2 is a schematic view of the welded structure of two stainless steel composite components shown in FIG. 1; and

fig. 3 shows a schematic structural view of a stainless steel composite crucible provided according to an embodiment of the present invention.

Wherein the figures include the following reference numerals:

10. a stainless steel composite member; 11. a base layer; 12. coating;

31. a first weld groove; 311. a downhill slope surface; 312. connecting the bevel face; 313. an upper bevel face;

32. a second weld; 32', a second weld groove;

31', a first weld; 311', base layer welds; 312', transition layer welds; 313', cladding welds;

1. sealing the end; 2. a barrel; 3. a support plate; 4. a reinforcing plate.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As analyzed by the background technology of the application, after the connecting welding line of the end socket and the cylinder of the stainless steel composite crucible in the prior art is used for a period of time, the welding line cracks along the side heat affected zone of the cylinder, so that the crucible is frequently repaired, the service life is short, and the production cost of products such as magnesium alloy is high. In order to solve the problem that welding seams between a seal head and a cylinder of a stainless steel composite crucible in the prior art are easy to crack, the application provides a stainless steel composite device and a welding method thereof.

In an exemplary embodiment of the present application, a stainless steel composite device is provided, as shown in fig. 1 and 2, the stainless steel composite device includes two stainless steel composite members 10 and a weld, each stainless steel composite member 10 includes a base layer 11 and a clad layer 12 correspondingly welded, the base layer 11 is a low carbon steel layer, and the clad layer 12 is stainless steel; the welding seam, weld two stainless steel composite members 10, the welded truncated edge is set up in the basic unit 11 and the root has no gap, the welding seam includes the first welding seam 31 ', the first welding seam 31 ' is set up in the 12 side of cladding, the first welding seam 31 ' has the first welding seam groove 31, the first welding seam groove 31 includes two bevel faces, each stainless steel composite member 10 has a bevel face, wherein a bevel face includes the bevel face 311, connects the bevel face 312 and the bevel face 313, the bevel face 311 is set up in the basic unit 11; the connection bevel face 312 is arranged in the first base layer 11, and the included angle between the connection bevel face 312 and the downgrade bevel face 311 is more than or equal to 120 degrees and less than 180 degrees; the upper bevel surface 313 and the lower bevel surface 311 are connected by a connection bevel surface 312 and extend from the base layer 11 to the coating layer 12.

The upper bevel face 313 and the lower bevel face 311 of one of the bevel faces of the first weld groove 31 of the weld are connected through the connection bevel face 312 and extend to the cladding 12 through the base layer 11, so that the weld is increased relative to the bevel face in the prior art on the basis of not increasing the bevel angle, the volume of the first weld 31 ' arranged in the groove is increased, when the weld is applied to a stainless steel composite crucible, the fusion line position of the first weld 31 ' avoids the area with serious heat influence, the cracking of the first weld 31 ' is effectively relieved, and the service life of the stainless steel composite crucible is prolonged.

The groove angle of each groove in the present application is within the standard range of the prior art, that is, within the range of 55 ° to 65 °, unless otherwise specified.

In order to improve the workability of the groove and the compactness of the weld, it is preferable that the joint between the upper groove surface 313 and the connection groove surface 312 and/or the joint between the lower groove surface 311 and the connection groove surface 312 have a round chamfer as shown in fig. 1, and the radius R of the round chamfer is 1 to 3 mm.

In order to save welding cost, the extension length of the connection bevel face 312 is preferably 3-8 mm. In addition, in order to enhance the welding effect of the first weld 31', the connection bevel surface 312 is preferably parallel to the connection surface of the base layer 11 and the cladding layer 12, and the angle of the upper bevel surface 313 is preferably the same as the angle of the lower bevel surface 311.

In order to improve the welding firmness and save the welding cost, the width of the truncated edge is preferably 3-8 mm, the thickness of the base layer 11 is preferably 25-35 mm, and the thickness of the coating layer 12 is more preferably 4-8 mm.

The bevel surfaces of the present application may be bevel surfaces of a conventional type, and preferably, the upper bevel surface 313 and the lower bevel surface 311 are each independently a V-shaped bevel surface or a U-shaped bevel surface, and the other bevel surface of the first weld groove 31 is preferably a V-shaped bevel surface or a U-shaped bevel surface.

In another embodiment of the present application, as shown in fig. 1 and 2, the welding seam further includes a second welding seam 32 ', the second welding seam 32 ' is disposed on the side of the base layer 11 of the two stainless steel composite members 10, the second welding seam 32 ' has a second welding seam bevel 32, the second welding seam bevel 32 is a V-shaped bevel or a U-shaped bevel, the second welding seam bevel 32 is disposed in the base layer 11, and preferably, the depth of the second welding seam bevel 32 is 12-18 mm. By providing the second weld 32 'in cooperation with the first weld 31', the amount of weld distortion is reduced.

On the basis of the groove shape of the first weld 31 ', in order to further improve the welding capacity of the weld, it is preferable that as shown in fig. 2, the first weld 31' includes a base weld 311 ', a transition weld 312', and a cladding weld 313 ', and the base weld 311' is disposed in the first weld groove 31 corresponding to the lower groove surface 311; the transition layer weld 312 'extends from the surface of the base layer weld 311' into the first weld groove 31 corresponding to the upper bevel surface 313. The first welding seam 31 'is divided into three parts, so that a suitable welding method and a welding material can be conveniently selected according to the material of an object to be welded, and the overall welding capacity of the first welding seam 31' is further improved. The coating welding line 313 ' is arranged on the surface of the transition layer welding line 312 ' and is provided with a residual height part protruding out of the surface of the coating 12, preferably, the height of the residual height part is less than or equal to 2mm, and the welding line is polished after the welding is finished through the residual height part left on the coating welding line 313 ', so that the welding line and the stainless steel composite component 10 are in smooth transition.

Preferably, in order to adapt to the materials of the base layer 11 of the low carbon layer and the cladding layer 12 of the stainless steel, such as the cladding layers 12 of the base layers 11 and 310S of the Q345R material, the welding materials of the base layer welding seam 311 ', the transition layer welding seam 312' and the cladding layer welding seam 313 'are different, and the welding material of the base layer welding seam 311' preferably comprises a carbon steel high-manganese submerged arc welding wire, such as H10Mn2, H10MnSi, H08MnA carbon steel high-manganese submerged arc welding wire and SJ101, HJ431 and HJ welding flux 350; the preferred welding materials for the transition layer weld 312' include nickel alloy electrodes, such as ENiCrFe-2 electrodes, ENiCrFe-1 electrodes, and ENiCrFe-3 electrodes; the preferred welding material for clad weld 313' includes stainless steel welding rods, such as A412 welding rod, A407 welding rod, A402 welding rod.

On the basis of fully exerting the welding capacity of the transition layer welding seam 312 ', in order to reduce welding cost, the thickness of the transition layer welding seam 312 ' is preferably 3-6 mm, and the thickness of the transition layer welding seam 312 ' corresponding to the base layer 11 is preferably 1.5-3 mm.

In a preferred embodiment of the present application, as shown in fig. 3, the above-mentioned stainless composite device is a stainless composite crucible, the stainless composite member 10 having the connection bevel face 312 is a cylinder 2, the other stainless composite member 10 is a cap 1, preferably, one end of the cap 1 welded to the cylinder 2 is a straight end, and further preferably, the straight end has a straight edge length of 60 to 70 mm. By prolonging the straight edge of the straight edge end, the edge of the welding line of the end socket 1 and the cylinder 2 is kept away from the direct heating area by about 110mm, and the welding line is prevented from cracking along the side fusion line of the cylinder 2 due to the aging and performance reduction of the welding line under the direct action of a heat source.

In another exemplary embodiment of the present application, there is provided a welding method of the above stainless steel composite device, including: step S1, processing a first weld groove 31 of any one of the stainless steel composite devices on two stainless steel composite components 10; step S2, aligning the base layer 11 and the cladding layer 12 of the two stainless steel composite components 10, and aligning the cladding layer 12 and the base layer 11; step S3, using a first welding material to start first welding from the root of the first weld groove 31, and after the welding of the position of the downward notch surface 311 of the first weld groove 31 corresponding to the groove is completed, replacing the first welding material with a second welding material to perform second welding to a certain position in the corresponding coating 12; and replacing the second welding material with a third welding material, and carrying out third welding till the welding of the welding seam groove is completed.

The first welding material, the second welding material and the third welding material can be the same or different.

Because the upper bevel face 313 and the lower bevel face 311 of one of the bevel faces of the first weld groove 31 of the first weld 31 'are connected through the connection bevel face 312 and extend from the base layer 11 to the cladding layer 12, the weld is increased relative to the bevel face in the prior art on the basis of not increasing the bevel angle, and further the volume of the first weld 31' arranged in the groove is increased.

In order to reduce welding deformation and improve welding capability, it is preferable that the weld further includes a second weld 32', the step S1 further includes machining a second weld groove 32 on the two stainless steel composite members 10, and the step S3 further includes performing a fourth welding from a root of the second weld groove 32 using the first welding material.

In an embodiment of the application, after the step S3, the welding method further includes performing a heat treatment on the welded part, where the heat treatment includes maintaining the temperature at 500-550 ℃ for 3-5 hours. The heat treatment eliminates stress between the weld and the welded stainless steel composite member 10, and improves the weld firmness.

Different welding materials and conditions are selected for each welding aiming at the materials of each base layer 11 and each coating layer 12, preferably, the first welding and the fourth welding are submerged-arc welding, the first welding material comprises a carbon steel high-manganese submerged-arc welding wire and a welding flux, the current of the first welding and the fourth welding is 450-500A respectively, the arc voltage is 30-35V respectively, the speed is 40-45 cm/min respectively, the diameter of the carbon steel high-manganese submerged-arc welding wire is preferably 3-5 mm, and the thickness of the seam of the submerged-arc welding is smaller than that of the carbon steel high-manganese welding wire.

Preferably, the second welding is manual welding, the second welding material comprises a nickel alloy welding rod, and the diameter of the nickel alloy welding rod is preferably 3-5 mm; preferably, the third welding is manual welding, the third welding material comprises a stainless steel welding rod, the diameter of the stainless steel welding rod is 3-5 mm, the current of the second welding and the current of the third welding are 120-140A respectively, the arc voltage of the second welding and the arc voltage of the third welding are 18-25V respectively, and the speed of the second welding and the third welding are 10-15 cm/min respectively. When the second welding and the third welding are carried out, the operator is required not to swing and should move straight fast.

In order to enhance the effect of the welding material, it is preferable that the welding method further includes a process of cleaning a region of the stainless steel composite member 10 within 25mm from the root of the first weld groove 31 to remove impurities between step S1 and step S3. For example, the groove and the impurities such as rust and oil stain within 25mm from the root of the groove are cleaned up by physical methods such as wiping, and both sides of the coating 12 are cleaned by organic solvent.

In one embodiment, the stainless steel composite crucible further comprises a reinforcing plate 4 and a supporting plate 3, as shown in fig. 3, wherein the supporting plate 3 is close to one end of the cylinder 2 far away from the end socket 1, preferably the supporting plate 3 is 210mm away from the upper end of the cylinder 2, and the supporting plate 3 is welded with the outer wall of the cylinder 2; a plurality of stiffening plates 4 set up in backup pad 3 keep away from head 1 one side and along 2 circumference evenly distributed of barrel, and stiffening plate 4 welds with backup pad 3 and barrel 2, is provided with the hole for hoist on preferred each stiffening plate 4, and preferred stiffening plate 4 is 8. The diameter of the hoisting hole is 55 mm. The material of the supporting plate 3 and the reinforcing plate 4 is preferably the same as the material of the base layer 11 of the cylinder 2, for example, Q345R low carbon steel is used for both. When the reinforcing plate 4 is welded with the cylinder 2 and the supporting plate 3, the reinforcing plate 4 and the supporting plate 3 are welded from outside to inside, the welding is stopped when the distance between the reinforcing plate 4 and the supporting plate 3 and the cylinder is about 5mm, and then the reinforcing plate 4 and the cylinder 2 are welded.

The advantageous effects of the present application will be further described below with reference to examples and comparative examples.