CN110640278B - Terminal crack prevention process for Q420 high-strength steel flux copper liner method submerged-arc welding - Google Patents

Terminal crack prevention process for Q420 high-strength steel flux copper liner method submerged-arc welding Download PDF

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CN110640278B
CN110640278B CN201910944974.8A CN201910944974A CN110640278B CN 110640278 B CN110640278 B CN 110640278B CN 201910944974 A CN201910944974 A CN 201910944974A CN 110640278 B CN110640278 B CN 110640278B
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welding
plate
groove
arc
steel
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CN110640278A (en
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张继军
雷炳育
邵丹丹
陈立群
潘庆亮
杨楚文
吴伟平
张岩
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Guangzhou Huangchuan Marine Engineering Co ltd
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Guangzhou Huangchuan Marine Engineering Co ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00—Arc welding or cutting
    • B23K9/18—Submerged-arc welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K33/00—Specially-profiled edge portions of workpieces for making soldering or welding connections; Filling the seams formed thereby
    • B23K33/004—Filling of continuous seams
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00—Arc welding or cutting
    • B23K9/16—Arc welding or cutting making use of shielding gas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00—Arc welding or cutting
    • B23K9/235—Preliminary treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/18—Sheet panels
    • B23K2101/185—Tailored blanks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/02—Iron or ferrous alloys
    • B23K2103/04—Steel or steel alloys

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  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Arc Welding In General (AREA)
  • Butt Welding And Welding Of Specific Article (AREA)

Abstract

The invention provides a terminal crack prevention process for submerged arc welding of Q420 high-strength steel by a flux copper backing method, which comprises the following steps of: processing a Y-shaped welding groove at the welding position of the steel plate, and cleaning an oxide layer and impurities on the surface of the Y-shaped welding groove and in the range of 20mm around the Y-shaped welding groove after processing; assembling and welding the groove to be welded of the steel plate in a positioning manner; preparing an arc striking plate and an arc quenching plate; installing an arc striking plate and an arc extinguishing plate at two ends of a welding groove; performing backing welding on the initial end of the Y-shaped welding groove of 200 plus 250mm and the terminal end of the Y-shaped welding groove of 450 plus 500 mm; selecting a welding material meeting the requirements to implement FCB submerged arc welding; heating and welding the trapezoidal region of the terminal; and after the welding line is cooled after the welding is finished, cutting arc striking plates and arc extinguishing plates at two ends of the welding line. The method can effectively prevent the problem of terminal welding cracks of Q420 high-strength steel flux copper liner method submerged-arc welding, and reduce the repair workload of the terminal cracks of the welded seam.

Description

Terminal crack prevention process for Q420 high-strength steel flux copper liner method submerged-arc welding
Technical Field
The invention relates to a welding process of a high-strength steel thick plate, in particular to a terminal crack prevention process of submerged arc welding of Q420 high-strength steel by a flux copper liner method.
Background
With the improvement of technical indexes and service life requirements of buildings such as bridges, tunnels and the like, the bearing reinforced concrete structure is gradually replaced by a design structure of high-strength structural steel, and the steel adopted by the design is developed towards the direction of high strength and large thickness. Q420 is a low-alloy high-strength structural steel having a yield strength level of 420MPa or more, which has been applied to a steel box girder structure, a truss structure of a bridge building, a steel shell structure of a tunnel building, and the like.
The welding flux copper backing method submerged arc welding, FCB submerged arc welding for short, is a single-side welding double-side forming submerged arc welding technology, the welding process adopts double wires or three wires for welding, the copper backing and the back welding flux are arranged on the back of a steel plate groove, the back welding seam can be formed forcibly and the back of the welding seam is protected, and the surface welding flux is spread on the surface of the steel plate groove to protect welding arcs and the surface welding seam. The welding process has higher welding heat input and welding speed, and is usually configured at a splicing plate station of a plane subsection production line, so that the splicing plate welding efficiency can be improved.
However, the FCB submerged arc welding is a welding technique with a large heat input, and when the steel sheet is welded to the end, the end of the steel sheet is rotated and deformed to be opened, and the weld metal which is just solidified and is still in a brittle state is pulled apart to form an end crack. At present solution adopts the cascaded restraint welding seam method in terminal to carry out the compulsory restraint to the terminal usually, avoids among the welding process terminal to take place to warp, though can avoid terminal crackle, but restraint welding seam position often can't weld through, need repair the terminal back after welding, increase welding work volume.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a terminal crack prevention process for Q420 high-strength steel flux copper liner submerged arc welding, which can effectively prevent the problem of terminal welding cracks and reduce the repair workload of the terminal cracks of welded seams.
The technical scheme of the invention is realized as follows: a terminal crack prevention process for Q420 high-strength steel submerged arc welding by a flux copper backing method comprises the following steps:
step 1, processing a Y-shaped welding groove at the welding position of a steel plate, wherein the thickness of the steel plate is different, and the corresponding parameters of the Y-shaped welding groove are different, and the method specifically comprises the following steps:
a steel plate with the thickness of 10mm or more and t less than 17mm, the opening angle is 57-63 degrees, the truncated edge is 2-4mm, and the root gap is 0-1 mm;
a steel plate with the thickness of 17mm or more and t less than 23mm, the opening angle is 47-53 degrees, the truncated edge is 2-4mm, and the root gap is 0-1 mm;
a steel plate with the thickness of 23mm or more and t less than 31mm, the opening angle is 42-48 degrees, the truncated edge is 4-6mm, and the root gap is 0-1 mm;
a steel plate with the thickness of 31mm or more and t or less than 40mm, the opening angle is 42-48 degrees, the truncated edge is 5-7mm, and the root gap is 0-1 mm;
after the Y-shaped welding groove is processed, cleaning an oxide layer and impurities on the surface of the Y-shaped welding groove and in the range of 20mm around the Y-shaped welding groove;
step 2, assembling the to-be-welded groove of the steel plate, and then performing semi-automatic CO2Performing positioning welding on the front surface of the Y-shaped welding groove in a gas shielded welding mode, wherein the thickness of a positioning welding line is 4-5 mm;
step 3, preparing an arc striking plate and an arc extinguishing plate, and respectively digging a 150-plus-200 mm-long air gouging groove from the center to one side edge along the length direction of the width central line of the arc striking plate and the width central line of the arc extinguishing plate in an air gouging mode; the arc striking plate, the arc extinguishing plate and the welding plate are the same in material, thickness, groove size, truncated edge and root gap;
step 4, assembling the Y-shaped welding groove of the middle steel plate by the gouging groove of the run-on plate and the arc-off plate, ensuring that the run-on plate and the arc-off plate are flush with the steel plate, and then adopting a semi-automatic CO2The gas shielded welding installs the arc striking plate and the arc extinguishing plate at two ends of the welding groove;
step 5, adopting semi-automatic CO2Performing backing welding on the initial end 200 and 250mm of the Y-shaped welding groove and the terminal end 450 and 500mm of the Y-shaped welding groove in a gas shielded welding mode, wherein the thickness of a backing weld bead is controlled to be 4-5 mm;
step 6, adopting a flux-cored wire with the diameter specification of 4.8mm and the brand of Shen steel US-36LS as a first electrode welding wire, a flux-cored wire with the diameter specification of 4.8mm and the brand of Shen steel US-36T as a second electrode welding wire, a flux-cored wire with the diameter specification of 6.4mm and the brand of Shen steel US-36T as a third electrode welding wire, and matching a surface welding flux with the brand of Shen steel PF-I55E and a back welding flux with the brand of Shen steel PF-I50R to implement FCB submerged arc welding;
step 7, heating the terminal trapezoidal area to ensure that the temperature of the area reaches 600-650 ℃ before the welding head welds the area, and then welding the terminal trapezoidal area;
and 8, cutting off arc striking plates and arc extinguishing plates at two ends of the welding line after the welding line is cooled.
Further, in the step 2, the step 4 and the step 5, the flux-cored wire used in the welding process meets the specified requirements of E81T1-K2CJ in AWS A5.29 standard.
Further, in the step 2, the step 4 and the step 5, the flux-cored wire used for welding is a flux-cored wire of Tiantai TWE-81K 2.
Further, in step 8, cutting is performed by flame cutting or plasma cutting.
Compared with the prior art, the invention has the following advantages: according to the invention, the steel plate is strictly assembled and cleaned by strictly controlling the welding groove parameters, and the terminal is heated before being welded to the terminal by adopting a proper welding material, so that the crack resistance of the weld metal is increased, the rotary deformation of the terminal is reduced, and the generation of terminal cracks can be effectively prevented.
The method can reduce the generation rate of terminal cracks in the welding process of submerged arc welding of the Q420 high-strength steel by the flux copper liner method, can ensure that the terminal position of the steel plate can be completely welded, and can reduce the repair amount of the defects of the terminal welding cracks and incomplete penetration.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic view of a welding groove structure of Q420 high-strength steel;
FIG. 2 is an assembly view of Q420 high strength steel prior to welding;
FIG. 3 is a structural view of a pre-weld heating zone of Q420 high-strength steel.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The embodiment discloses a terminal crack prevention process for submerged arc welding of Q420 high-strength steel by a flux copper backing method, which is mainly applied to Q420 high-strength steel with the thickness of 10 mm-t less than 17mm and comprises the following steps:
step 1, processing a Y-shaped welding groove at the welding position of a steel plate, specifically referring to fig. 1, wherein the opening angle of the Y-shaped welding groove is 57-63 degrees, the truncated edge is 2-4mm, and the root gap is 0-1 mm; after the Y-shaped welding groove is processed, cleaning an oxide layer and impurities on the surface of the Y-shaped welding groove and in the range of 20mm around the Y-shaped welding groove;
in the invention, the setting of the groove parameters mainly relates to welding heat input and welding seam forming effect. According to the embodiment, the plate thickness is correctly matched with the groove parameters, so that the welding heat input and the welding seam forming effect are indirectly controlled.
The terminal cracks are weld heat cracks, and the greater the weld heat input, the greater the weld heat crack sensitivity, but the smaller the weld heat input is, the better, because too small a weld heat input is likely to form a lack of penetration and fusion of weld defects. Therefore, the groove parameters are reasonably designed according to the plate thickness, the welding heat input can be indirectly controlled, and a certain crack prevention effect is achieved.
Because the welding heat input of the thin plate is small, the groove with a large angle and a small truncated edge can better ensure the back forming. The welding heat input is increased along with the increase of the plate thickness, so that the welding groove angle can be properly reduced, and the size of the truncated edge of the groove can be increased in order to avoid burnthrough and prevent the welding heat input from being too large to increase the welding heat crack sensitivity. Therefore, the thin plate adopts the groove design with a large angle and a small truncated edge, and the thick plate adopts the groove design with a small angle and a large truncated edge.
Step 2, as shown in fig. 2, assembling the to-be-welded grooves of the steel plates, and then performing semi-automatic CO2Performing positioning welding on the front surface of the Y-shaped welding groove in a gas shielded welding mode, wherein the thickness of a positioning welding line is 4-5 mm;
when the tack weld is welded, the adopted flux-cored wire meets the regulation requirement of E81T1-K2CJ in AWS A5.29 standard so as to improve the crack resistance of the tack weld.
Specifically, in the step 2, the adopted welding wire is a flux-cored welding wire of Tiantai TWE-81K 2. Of course, the welding material adopted by the invention is not limited to flux-cored wire of Tantai TWE-81K2, and can be specifically selected according to the requirement as long as the welding material meets the specified requirement of E81T1-K2CJ in AWS A5.29 standard.
In this embodiment, if tack weld thickness undersize, can reduce tack weld's restraint effect, and this welding process welding heat input is great, and when the tack weld of welding process welding position melted, if its place ahead tack weld provided not enough restraint effect will the fracture lead to the steel sheet to warp, warp the accumulation to the terminal after, be unfavorable for the control of terminal crackle. If the thickness of the positioning welding is too large, on one hand, the electric arc penetration capability is weakened, so that a welding bead on the back side of the positioning welding position is too narrow, even the defect of incomplete penetration occurs, the back side forming is influenced, and on the other hand, the normal operation of a front guide wheel of a welding head is influenced, and the welding stability is influenced.
Step 3, preparing an arc striking plate and an arc extinguishing plate, and respectively digging a 150-plus-200 mm-long air gouging groove from the center to one side edge along the length direction of the width central line of the arc striking plate and the width central line of the arc extinguishing plate in an air gouging mode; the arc striking plate, the arc extinguishing plate and the welding plate are the same in material, thickness, groove size, truncated edge and root gap;
in the embodiment of the invention, the gas planing groove is arranged on the arc striking and extinguishing plate, so that the welding groove of the steel plate to be welded and the gas planing groove of the arc striking and extinguishing plate can be in smooth transition in depth, and the phenomenon that the arc is suddenly changed in the process from the arc striking plate to the initial end of the groove and from the terminal end of the groove to the arc extinguishing plate to influence the welding stability is avoided.
The length, the width and the thickness of the welded plate are 15000mm, 3500mm and 14mm respectively, the length of the arc striking plate and the arc extinguishing plate can be 300mm and the width thereof can be 250mm, the arc striking plate and the arc extinguishing plate are Q420 high-strength steel thick plates, the thickness and the groove size of the arc striking plate and the arc extinguishing plate are the same as those of the welded plate in the embodiment of the invention, the stability of the formal welding seam welding process can be effectively ensured, and the welding defects at the beginning end and the end of the formal welding seam are avoided.
Step 4, as shown in fig. 2, assembling the Y-shaped welding groove of the middle steel plate by using the gouging groove of the arc striking plate and the arc extinguishing plate, ensuring that the arc striking plate and the arc extinguishing plate are level to the steel plate, and then adopting a semi-automatic CO2The gas shielded welding installs the arc striking plate and the arc extinguishing plate at two ends of the welding groove;
in the step 3, the adopted flux-cored wire also needs to meet the specified requirements of E81T1-K2CJ in AWS A5.29 standard so as to improve the crack resistance of the positioning welding seam. Specifically, in the step, the adopted welding wire is a flux-cored welding wire of Tiantai TWE-81K 2. Similarly, the welding material used in the invention is not limited to flux-cored welding wire of Tantai TWE-81K2, and can be specifically selected according to requirements as long as the welding material meets the specified requirements of E81T1-K2CJ in AWS A5.29 standard.
Step 5, adopting semi-automatic CO2Performing backing welding on the initial end 200 and 250mm of the Y-shaped welding groove and the terminal end 450 and 500mm of the Y-shaped welding groove in a gas shielded welding mode, wherein the thickness of a backing weld bead is controlled to be 4-5 mm;
in this embodiment, the backing weld acts similar to a tack weld, but it is more demanding and requires more constraining action because the terminal end of the steel plate has the greatest tendency to undergo rotational deformation during welding, and then the beginning end of the steel plate. However, the welding seam is too high, which affects the electric arc penetration ability and the normal operation of the nose guide wheel, so the restraint effect can be improved only by increasing the length of the welding seam, the positioning welding seam of the initial end and the terminal end of the steel plate is changed into the backing welding seam, and the backing welding seam of the terminal end of the steel plate has longer requirement than that of the initial end of the steel plate.
In the step 5, the adopted flux-cored wire meets the regulation requirement of E81T1-K2CJ in AWS A5.29 standard so as to improve the crack resistance of the positioning welding seam. Specifically, in the step 4, the adopted welding wire is a flux-cored welding wire of Tiantai TWE-81K 2. Similarly, the welding material used in the step is not limited to flux-cored welding wire of Tantai TWE-81K2, and can be specifically selected according to requirements as long as the welding material meets the requirements specified in AWS A5.29 standard E81T1-K2 CJ.
Step 6, adopting a flux-cored wire with the diameter specification of 4.8mm and the brand of Shen steel US-36LS as a first electrode welding wire, a flux-cored wire with the diameter specification of 4.8mm and the brand of Shen steel US-36T as a second electrode welding wire, a flux-cored wire with the diameter specification of 6.4mm and the brand of Shen steel US-36T as a third electrode welding wire, and matching a surface welding flux with the brand of Shen steel PF-I55E and a back welding flux with the brand of Shen steel PF-I50R to implement FCB submerged arc welding;
in the embodiment, welding wires with the grades of Shen steel US-36LS and US-36T, US-36T are adopted to match a surface welding flux PF-I55E and a back welding flux PF-I50R, so that the weld deposit metal has low carbon content and higher alloy element contents such as Mn, Mo and the like, the high-temperature plasticity of the weld metal can be ensured, and the weld metal has better capability of resisting hot cracking.
Step 7, as shown in fig. 3, heating the terminal trapezoidal area by using a torch to ensure that the temperature of the area reaches 600-;
before the formal welding seam is welded to the terminal, the trapezoidal area of the terminal is heated to 600-650 ℃, so that the rotary deformation caused by the internal stress of the steel plate terminal can be effectively relieved, and the large rotary deformation of the welding joint when the welding joint is welded to the steel plate terminal is avoided to form a welding crack.
Certainly, the heating time needs to be controlled in the steel plate terminal heating process, so that the heating work in the terminal area can be completed as required before the welding head is welded to the heating position, and the welding head can complete the steel plate terminal welding according to the preset conditions.
And 8, cutting off arc striking plates and arc extinguishing plates at two ends of the welding line after the welding line is cooled.
Specifically, a flame cutting or plasma cutting mode is adopted to cut off arc leading plates and arc extinguishing plates at two ends of the welding line.
Example 2
The embodiment discloses a terminal crack prevention process for submerged arc welding of Q420 high-strength steel by a flux copper backing method, which is mainly applied to Q420 high-strength steel with the thickness of 17 mm-23 mm, and specifically comprises the following steps:
step 1, processing a Y-shaped welding groove at the welding position of a steel plate, specifically referring to fig. 1, wherein the opening angle of the Y-shaped welding groove is 47-53 degrees, the truncated edge is 2-4mm, and the root gap is 0-1 mm; after the Y-shaped welding groove is processed, cleaning an oxide layer and impurities on the surface of the Y-shaped welding groove and in the range of 20mm around the Y-shaped welding groove;
steps 2 to 8 are the same as those in example 1, and will not be described again.
The relation between the design concept of the opening angle and the size of the truncated edge and the thickness of the Q420 high-strength steel is specifically described in embodiment 1, and is not described herein again.
Example 3
The embodiment discloses a terminal crack prevention process for submerged arc welding of Q420 high-strength steel by a flux copper backing method, which is mainly applied to Q420 high-strength steel with the thickness of 23 mm-31 mm, and specifically comprises the following steps:
step 1, processing a Y-shaped welding groove at the welding position of a steel plate, specifically referring to fig. 1, wherein the opening angle of the Y-shaped welding groove is 42-48 degrees, the truncated edge is 4-6mm, and the root gap is 0-1 mm; after the Y-shaped welding groove is processed, cleaning an oxide layer and impurities on the surface of the Y-shaped welding groove and in the range of 20mm around the Y-shaped welding groove;
steps 2 to 8 are the same as those in example 1, and will not be described again.
The relation between the design concept of the opening angle and the size of the truncated edge and the thickness of the Q420 high-strength steel is specifically described in embodiment 1, and is not described herein again.
Example 4
The embodiment discloses a terminal crack prevention process for submerged arc welding of Q420 high-strength steel by a flux copper backing method, which is mainly applied to Q420 high-strength steel with the thickness of 31 mm-40 mm, and specifically comprises the following steps:
step 1, processing a Y-shaped welding groove at the welding position of a steel plate, specifically referring to fig. 1, wherein the opening angle of the Y-shaped welding groove is 47-53 degrees, the truncated edge is 5-7mm, and the root gap is 0-1 mm; after the Y-shaped welding groove is processed, cleaning an oxide layer and impurities on the surface of the Y-shaped welding groove and in the range of 20mm around the Y-shaped welding groove;
steps 2 to 8 are the same as those in example 1, and will not be described again.
The relation between the design concept of the opening angle and the size of the truncated edge and the thickness of the Q420 high-strength steel is specifically described in embodiment 1, and is not described herein again.
In conclusion, according to the Q420 high-strength steel with different thicknesses, welding groove parameters are strictly controlled, steel plate assembly and cleaning are strictly carried out, a proper welding material is adopted for welding, and the terminal is heated before being welded to the terminal, so that the crack resistance of the weld metal is improved, the rotary deformation of the terminal is reduced, and the generation of terminal cracks can be effectively reduced.
The method can reduce the generation rate of terminal cracks in the welding process of submerged arc welding of the Q420 high-strength steel by the flux copper liner method, can ensure that the terminal position can be completely welded, and reduces the repair amount of the defects of the terminal welding cracks and incomplete penetration.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (4)

1. A terminal crack prevention process for Q420 high-strength steel submerged arc welding by a flux copper backing method is characterized by comprising the following steps:
step 1, processing a Y-shaped welding groove at the welding position of a steel plate, wherein the thickness of the steel plate is different, and the corresponding parameters of the Y-shaped welding groove are different, and the method specifically comprises the following steps:
a steel plate with the thickness of 10mm or more and t less than 17mm, the opening angle is 57-63 degrees, the truncated edge is 2-4mm, and the root gap is 0-1 mm;
a steel plate with the thickness of 17mm or more and t less than 23mm, the opening angle is 47-53 degrees, the truncated edge is 2-4mm, and the root gap is 0-1 mm;
a steel plate with the thickness of 23mm or more and t less than 31mm, the opening angle is 42-48 degrees, the truncated edge is 4-6mm, and the root gap is 0-1 mm;
a steel plate with the thickness of 31mm or more and t or less than 40mm, the opening angle is 42-48 degrees, the truncated edge is 5-7mm, and the root gap is 0-1 mm;
after the Y-shaped welding groove is processed, cleaning an oxide layer and impurities on the surface of the Y-shaped welding groove and in the range of 20mm around the Y-shaped welding groove;
step 2, assembling the to-be-welded groove of the steel plate, and then performing semi-automatic CO2Performing positioning welding on the front surface of the Y-shaped welding groove in a gas shielded welding mode, wherein the thickness of a positioning welding line is 4-5 mm;
step 3, preparing an arc striking plate and an arc extinguishing plate, and respectively digging a 150-plus-200 mm-long air gouging groove from the center to one side edge along the length direction of the width central line of the arc striking plate and the width central line of the arc extinguishing plate in an air gouging mode; the arc striking plate, the arc extinguishing plate and the welding plate are the same in material, thickness, groove size, truncated edge and root gap;
step 4, assembling the Y-shaped welding groove of the middle steel plate by the gouging groove of the run-on plate and the arc-off plate, ensuring that the run-on plate and the arc-off plate are flush with the steel plate, and then adopting a semi-automatic CO2The gas shielded welding installs the arc striking plate and the arc extinguishing plate at two ends of the welding groove;
step 5, adopting semi-automatic CO2The gas shielded welding mode carries out backing welding on the initial end of the Y-shaped welding groove of 200-250mm and the terminal end of the Y-shaped welding groove of 450-500mm, wherein the thickness of a backing weld bead is controlled to be within the range of4-5mm；
Step 6, adopting a flux-cored wire with the diameter specification of 4.8mm and the brand of Shen steel US-36LS as a first electrode welding wire, a flux-cored wire with the diameter specification of 4.8mm and the brand of Shen steel US-36T as a second electrode welding wire, a flux-cored wire with the diameter specification of 6.4mm and the brand of Shen steel US-36T as a third electrode welding wire, and matching a surface welding flux with the brand of Shen steel PF-I55E and a back welding flux with the brand of Shen steel PF-I50R to implement FCB submerged arc welding;
step 7, heating the terminal trapezoidal area to ensure that the temperature of the area reaches 600-650 ℃ before the welding head welds the area, and then welding the terminal trapezoidal area;
and 8, cutting off arc striking plates and arc extinguishing plates at two ends of the welding line after the welding line is cooled.
2. The process of claim 1, wherein in steps 2, 4 and 5, the flux cored wire used in welding meets the requirements of the AWS A5.29 standard specification E81T1-K2 CJ.
3. The process of claim 2, wherein in steps 2, 4 and 5, the flux cored wire used in the welding is a flux cored wire of Tiantai TWE-81K 2.
4. The process of claim 1, wherein in step 8, the cutting is performed by flame cutting or plasma cutting.
CN201910944974.8A 2019-09-30 2019-09-30 Terminal crack prevention process for Q420 high-strength steel flux copper liner method submerged-arc welding Active CN110640278B (en)

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JPH05185234A (en) * 1992-01-14 1993-07-27 Nippon Steel Corp Termination processing method for multiple electrode one-side submerged arc welding process
JPH11138266A (en) * 1997-11-10 1999-05-25 Ishikawajima Harima Heavy Ind Co Ltd Tandem submaerged arc welding method
CN102398105A (en) * 2010-09-15 2012-04-04 中国石油天然气集团公司 Process for integral hardening and tempering of X80 steel-grade automatic submerged arc welding pipe fittings
CN102009255B (en) * 2010-12-01 2013-06-19 武昌船舶重工有限责任公司 Downward and butt welding process for high strength steel for ship structure
CN105983761A (en) * 2015-01-31 2016-10-05 重庆展申机械厂 High-strength steel welding process
CN105583506A (en) * 2016-03-21 2016-05-18 上海绿地建设(集团)有限公司 Welding process for high-performance steel
CN106624614B (en) * 2016-10-11 2019-08-23 武汉钢铁有限公司 A kind of manufacturing process of the high-strength welded tube of heavy caliber thick wall
CN107322132A (en) * 2017-08-28 2017-11-07 上海外高桥造船有限公司 A kind of welding method more than 38mm thickness hull plates
CN109676220A (en) * 2019-01-31 2019-04-26 湘潭电机股份有限公司 A kind of slab butt welding method

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