CN116586725A - Welding method of large-scale welding seam of low-temperature cast steel and low-alloy steel - Google Patents
Welding method of large-scale welding seam of low-temperature cast steel and low-alloy steel Download PDFInfo
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- CN116586725A CN116586725A CN202310529160.4A CN202310529160A CN116586725A CN 116586725 A CN116586725 A CN 116586725A CN 202310529160 A CN202310529160 A CN 202310529160A CN 116586725 A CN116586725 A CN 116586725A
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- 238000003466 welding Methods 0.000 title claims abstract description 198
- 238000000034 method Methods 0.000 title claims abstract description 56
- 229910000851 Alloy steel Inorganic materials 0.000 title claims abstract description 27
- 229910001208 Crucible steel Inorganic materials 0.000 title claims abstract description 22
- 239000000463 material Substances 0.000 claims abstract description 22
- 238000010438 heat treatment Methods 0.000 claims abstract description 10
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 238000005520 cutting process Methods 0.000 claims abstract description 4
- 239000011324 bead Substances 0.000 claims description 8
- 238000004321 preservation Methods 0.000 claims description 4
- 230000000630 rising effect Effects 0.000 claims description 2
- 238000001816 cooling Methods 0.000 claims 1
- -1 oxide skin Substances 0.000 abstract 1
- 238000012360 testing method Methods 0.000 description 10
- 229910000831 Steel Inorganic materials 0.000 description 6
- 238000005266 casting Methods 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000005498 polishing Methods 0.000 description 3
- 238000000137 annealing Methods 0.000 description 2
- 239000010953 base metal Substances 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000037452 priming Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005485 electric heating Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000009863 impact test Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000010421 standard material Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
Classifications
-
- 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
- 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
- B23K9/00—Arc welding or cutting
- B23K9/32—Accessories
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Mechanical Engineering (AREA)
- Arc Welding In General (AREA)
Abstract
The invention relates to the technical field of welding, and particularly discloses a method for welding a large-scale welding seam of low-temperature cast steel and low-alloy steel, which comprises the following steps: cutting a groove at a to-be-welded part of a material, (2) removing impurities such as oxide skin, oil stain and the like within a range of 40-60 mm around the groove, (3) preheating the material to 150-250 ℃, carrying out positioning welding on the groove to obtain a positioning welding line, (5) carrying out backing welding on the groove to obtain a backing welding line, (6) carrying out arc welding on the positioning welding line and the backing welding line by using submerged arc welding, (7) carrying out back gouging on the groove to obtain a residual welding line, (8) carrying out submerged arc welding on the residual welding line, and (9) carrying out postweld heat treatment on the welding part after welding is finished.
Description
Technical Field
The invention relates to the technical field of welding, in particular to a method for welding a large-scale welding seam of low-temperature cast steel and low-alloy steel.
Background
The welding is a production process and a connection mode for generating the combination between atoms of two workpieces by heating and pressurizing or the combination of the two, and the welding process is widely applied to various mechanical manufacturing, wherein heavy machinery is used as a part of the machinery, some important parts are mainly cast steel parts, and the welding between the heavy machinery and other structural parts (such as low alloy steel parts) is mainly important welding seams, and the welding quantity of the welding seams is large generally and the welding difficulty is high. In the traditional welding process of the steel casting and the low alloy steel, the welding quality is greatly affected by the capability of a welder, the performance is unstable, the labor intensity of the welder is high, and the welding efficiency is low.
As one of the mechanized welding methods with higher production efficiency, the submerged arc welding greatly reduces the working strength of welders. However, compared with other traditional welding methods, the method has the advantages that the heat input change range is larger, if the welding parameters are unreasonable during welding, the performance of the welding seam is greatly affected, and particularly the low-temperature impact toughness of the welding seam is greatly affected, so that the service life of a welding piece is influenced.
Therefore, it is necessary to provide a method for welding a large-sized weld joint between a low-temperature cast steel and a low-alloy steel, so as to improve the low-temperature impact toughness of the weld joint and the service life of a welded part.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provides a method for welding a large-scale welding seam of low-temperature cast steel and low-alloy steel.
The technical scheme of the invention is as follows:
a welding method of a large-scale welding seam of low-temperature cast steel and low-alloy steel comprises the following steps:
(1) Cutting a groove at a to-be-welded part of the material;
(2) Removing impurities such as oxide skin, greasy dirt and the like within the range of 40 mm-60 mm around the groove;
(3) Preheating the material to 150-250 ℃;
(4) Carrying out positioning welding on the groove to obtain a positioning welding line;
(5) Backing welding is carried out on the groove to obtain a backing weld;
(6) Arc welding the positioning welding seam and the backing welding seam by using submerged arc welding;
(7) Back gouging the groove to obtain a residual welding seam;
(8) Welding the remaining weld using submerged arc welding;
(9) And after the welding is finished, performing postweld heat treatment on the welding part.
Further, the type of the groove in the step (1) is a double V-groove.
Further, the positioning welding in the step (4) adopts a welding method of combining flux-cored wires and arc welding.
Further, the backing welding in the step (5) adopts a welding method of combining flux-cored wires and arc welding.
Further, the angle of the groove is 55-70 degrees, the blunt edge of the groove is 1-4 mm, and the gap of the groove is 1-3 mm.
Further, the ambient temperature of the material in the welding process is 150-250 ℃.
Further, the welding beads of the submerged arc welding are multi-layered, and each layer of welding bead is multi-layered.
Further, in the step (4), the thickness of the welding seam, the length of the welding seam and the interval between the welding seams are all matched.
Further, the back chipping can adopt a polishing or carbon arc gouging mode.
Furthermore, the positioning welding seam and the backing welding seam are welded by adopting the same welding method and parameters, the welding materials are flux-cored wires meeting the ABS class society standard 5YQ460SAH5, the welding current is 180-220A, the voltage is 26-32V, and the gas flow rate is 15-25L/min.
The welding method of the large-sized welding seam of the low-temperature cast steel and the low-alloy steel adopts the combined welding method of flux-cored arc welding bottoming and submerged arc welding filling and capping, and is controlled by preheating before welding, post-welding heat treatment and the like, so that the welding seam performance of the material can be ensured to meet the requirements of specifications of a class society, the welding method is suitable for the large-sized welding seam with special requirements on low-temperature performance, and compared with the prior art, the technical scheme can effectively improve the low-temperature impact toughness of the welding seam and prolong the service life of a welding piece.
Drawings
FIG. 1 is a schematic view of a groove structure;
fig. 2 is a schematic view of a weld bead.
Detailed Description
In order to make the technical means, technical features, objects and technical effects of the present invention easy to understand, the present invention will be further described with reference to the specific drawings.
Embodiment one:
the present invention will be further described with reference to the accompanying drawings, taking the welding of a large-scale weld joint as a circumferential weld joint (wherein the low-temperature steel casting is made of American standard material A148 GR80-50, and the low-alloy steel is made of EH36 base material with the thickness of 50 mm) as an example, but the present invention is not limited to the following examples.
As shown in fig. 1, T is the thickness of the plate, α is the bevel angle, f is the blunt edge dimension, R is the root gap, and S is the bevel depth; as shown in fig. 2, 1 is the first pass weld and 1' is the first pass weld on the back.
A welding method of a large-scale welding seam of low-temperature cast steel and low-alloy steel comprises the following steps:
cutting a groove at a to-be-welded part of the material; removing impurities such as oxide skin, greasy dirt and the like within the range of 40 mm-60 mm around the groove; preheating the material to 150-250 ℃; carrying out positioning welding on the groove to obtain a positioning welding line; backing welding is carried out on the groove to obtain a backing weld; arc welding the positioning welding seam and the backing welding seam by using submerged arc welding; back gouging the groove to obtain a residual welding seam; welding the remaining weld using submerged arc welding; and after the welding is finished, performing postweld heat treatment on the welding part.
Preferably, the groove is a double V-groove.
Preferably, the localized welding adopts a welding method of combining flux-cored wires and arc welding.
Preferably, the backing welding in the step (5) adopts a welding method of combining flux-cored wires and arc welding.
Preferably, the angle of the groove is 55-70 degrees, the blunt edge size of the groove is 1-4 mm, and the gap of the groove is 1-3 mm.
Preferably, the ambient temperature of the material during welding is between 150 ℃ and 250 ℃.
Preferably, the submerged arc welding has multiple layers of welding beads, and each layer of welding bead has multiple welding layers.
Preferably, in the step (4), the thickness of the welding seam, the length of the welding seam and the interval between the welding seams are all matched.
Preferably, the back chipping can adopt a polishing or carbon arc gouging mode.
In construction, as shown in FIG. 1, grooves are machined on both sides of a base material, the groove angle alpha is 55-70 degrees, the blunt edge size f is 1-4 mm, the groove gap R is 1-3 mm, and the groove depth S is 1/3-2/3 of the thickness of the base material. And after the groove is machined, removing impurities such as oxide skin, greasy dirt and the like within a range of 50mm around the groove.
As shown in fig. 2, after the weld assembly is completed, a welding method of flux-cored arc welding is adopted for carrying out localized welding, the localized welding and a backing welding (first-pass weld 1 in fig. 2) are welded by adopting the same welding method and parameters, flux-cored wires meeting the ABS classification society standard 5YQ460SAH5 grade are selected as welding materials, the welding current is 180-220A, the voltage is 26-32V, the gas flow rate is 15-25L/min, a base metal is required to be preheated before welding, the welding can be preheated by adopting a flame baking or electric heating mode, the preheating temperature is 150 ℃ at the minimum and cannot be higher than 250 ℃, and the diameter of the flux-cored wires is 1.2mm;
and after the backing weld is finished, back chipping is carried out, and defective weld metal is removed completely. The back gouging mode can adopt a polishing or carbon arc gouging mode, and then adopts the same welding method and welding parameters as those of the bottoming weld to weld the first welding seam (the first welding seam 1' on the back in fig. 2) on the back.
After the two backing welds are welded, the workpiece is placed on a positioner platform, and the residual filling and capping welds are welded by submerged arc welding. The welding material is solid welding wires meeting the ABS class society standard 5Y40TMH5, the welding current is 450-540A, the voltage is 29-33V, the base metal is required to be preheated before welding, the preheating temperature is 150 ℃ at the minimum, the temperature between channels is 250 ℃ at the maximum, and the diameter of the adopted solid welding wires is 4.0mm; in the submerged arc welding process, the weld width of the single-pass weld should not be greater than 16mm.
In the welding process of submerged arc welding, the preheating or inter-channel temperature is measured from time to time, and if the temperature is less than 150 ℃, a baking gun is used for preheating a base material to be welded; if the temperature is higher than 250 ℃, the welding is stopped, and after the isothermal temperature is reduced to 250 ℃, the welding is performed. When welding, the welding bead should arrange the multilayer, and each layer should weld as many times as possible.
After the welding is completed, the workpiece is put into an annealing furnace (or a heating belt) for stress relief annealing. When the workpiece is put into the furnace, the temperature in the furnace is not higher than 315 ℃, the temperature rising rate is 55-100 ℃, the heat preservation temperature is 580+/-20 ℃, the heat preservation time is 2 hours, the temperature reducing rate is 55-100 ℃, and the temperature in the furnace is not higher than 315 ℃ when the workpiece is taken out of the furnace.
According to the standard requirements of ABS class society, the tensile strength of a welding line sample is more than or equal to 490MPa; after the bending sample is bent for 180 degrees, the length of the opening defect on the surface of the bending sample is less than or equal to 3mm or no opening defect exists; the temperature of the sample at the center of the welding line and the low alloy side in the impact sample should meet the material standard of low alloy steel (EH 36) at-40 ℃, and the temperature of the sample at the steel casting side should meet the material standard of the steel casting side (A148 GR 80-50) at-50 ℃.
The specific test results of the welding test are shown in tables 1 to 3:
table 1 tensile test results for weld test specimens:
note that: because the plate is thicker, the full-thickness welding sample tester cannot be broken, and 2 samples are adopted as 1 group of samples for testing.
The tensile strength requirements of the steel casting (A148 GR 80-50) are: 520 MPA or more
The tensile strength requirements of the low alloy steel (EH 36) are: (490-630) MPa.
Table 2 side bend test results for weld test specimens:
note that: because of the thicker plate, 2 samples were used as 1 set of samples for the test as required.
Table 3 shows the impact test results of the weld test specimens:
note that: the impact specimens were all 2mm from the specimen surface.
1) The impact value requirements for the steel casting (A148 GR 80-50) are: the test temperature was-50 ℃, the arithmetic mean of the 3 samples should not be below 34J, only a single value of 1 sample below 34J being allowed, and only not below 24J.
2) The impact value requirements for low alloy steel (EH 36) are: the test temperature was-40 ℃, the arithmetic mean of the 3 samples should not be below 34J, only a single value of 1 sample below 34J being allowed, and only not below 24J.
In summary, the mechanical properties of the welded joint in the embodiment of the invention meet the requirements of the ABS classification society, and the welding process evaluation obtains the acceptance of the ABS classification society.
The combined welding method of the flux-cored arc welding priming and submerged arc welding filling and capping is adopted by the method, and the weld joint performance of the low-temperature cast steel (A148 GR 80-50) and the low-alloy steel (EH 36) can be ensured to meet the requirements of the specifications of a class society through strict control of preheating temperature, electric parameters, postweld heat treatment and the like, so that the method is suitable for large-scale weld joints with special requirements on low-temperature (-40 ℃) performance, reduces the labor intensity of workers and improves the welding production efficiency.
The combined welding method of the flux-cored arc welding priming and submerged arc welding filling and capping is adopted by the method, and the weld joint performance of the low-temperature cast steel (A148 GR 80-50) and the low-alloy steel (EH 36) can be ensured to meet the requirements of the specifications of a class society through strict control of preheating temperature, electric parameters, postweld heat treatment and the like, so that the method is suitable for large-scale weld joints with special requirements on low-temperature (-40 ℃) performance, reduces the labor intensity of workers and improves the welding production efficiency.
The foregoing description is only of the preferred embodiments of the present invention and is not intended to limit the scope of the present invention. Equivalent changes and modifications of the invention are intended to fall within the scope of the present invention.
Claims (10)
1. The welding method of the large-scale weld joint of the low-temperature cast steel and the low-alloy steel is characterized by comprising the following steps of:
(1) Cutting a groove at a to-be-welded part of the material;
(2) Removing impurities such as oxide skin, greasy dirt and the like within the range of 40 mm-60 mm around the groove;
(3) Preheating the material to 150-250 ℃;
(4) Carrying out positioning welding on the groove to obtain a positioning welding line;
(5) Backing welding is carried out on the groove to obtain a backing weld;
(6) Arc welding the positioning welding seam and the backing welding seam by using submerged arc welding;
(7) Back gouging the groove to obtain a residual welding seam;
(8) Welding the remaining weld using submerged arc welding;
(9) And after the welding is finished, performing postweld heat treatment on the welding part.
2. The method for welding a large-sized weld joint between low-temperature cast steel and low-alloy steel according to claim 1, wherein the method comprises the following steps: the type of the groove in the step (1) is a double V-shaped groove.
3. The method for welding a large-sized weld joint between low-temperature cast steel and low-alloy steel according to claim 1, wherein the method comprises the following steps: and (3) the positioning welding in the step (4) adopts a welding method of combining flux-cored wires and arc welding.
4. The method for welding a large-sized weld joint between low-temperature cast steel and low-alloy steel according to claim 1, wherein the method comprises the following steps: and (3) the backing welding adopts a welding method of combining flux-cored wires and arc welding in the step (5).
5. The method for welding a large-sized weld joint between low-temperature cast steel and low-alloy steel according to claim 1, wherein the method comprises the following steps: the angle of the groove is 55-70 degrees, the blunt edge of the groove is 1-4 mm, and the gap of the groove is 1-3 mm.
6. The method for welding a large-sized weld joint between low-temperature cast steel and low-alloy steel according to claim 1, wherein the method comprises the following steps: the ambient temperature of the material in the welding process is 150-250 ℃.
7. The method for welding a large-sized weld joint between low-temperature cast steel and low-alloy steel according to claim 1, wherein the method comprises the following steps: the welding beads of the submerged arc welding are multi-layered, and each layer of welding beads is welded in multiple ways.
8. A method of welding a large weld of low temperature cast steel to low alloy steel as claimed in claim 3 wherein: and (3) in the step (4), the thickness of the welding seam, the length of the welding seam and the interval of the welding seam are matched with each other.
9. The method for welding a large-sized weld joint between low-temperature cast steel and low-alloy steel according to claim 1, wherein the method comprises the following steps: the temperature in the furnace for heat treatment in the step (9) is not higher than 315 ℃, the temperature rising rate is 55-100 ℃, the heat preservation temperature is 580+/-20 ℃, the heat preservation time is 2 hours, the cooling rate is 55-100 ℃, and the temperature in the furnace is not higher than 315 ℃ when the furnace is taken out.
10. The method for welding a large-sized weld joint between low-temperature cast steel and low-alloy steel according to claim 1, wherein the method comprises the following steps: the positioning welding seam and the backing welding seam are welded by adopting the same welding method and parameters, the welding materials are flux-cored wires meeting the ABS class society standard 5YQ460SAH5 grade, the welding current is 180-220A, the voltage is 26-32V, and the gas flow rate is 15-25L/min.
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CN202310529160.4A CN116586725A (en) | 2023-05-11 | 2023-05-11 | Welding method of large-scale welding seam of low-temperature cast steel and low-alloy steel |
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CN202310529160.4A CN116586725A (en) | 2023-05-11 | 2023-05-11 | Welding method of large-scale welding seam of low-temperature cast steel and low-alloy steel |
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CN202310529160.4A Pending CN116586725A (en) | 2023-05-11 | 2023-05-11 | Welding method of large-scale welding seam of low-temperature cast steel and low-alloy steel |
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