Welding method for sleeper beam assembly of railway vehicle

Abstract

The invention discloses a welding method for a sleeper beam assembly of a railway vehicle, which comprises the following steps: the sleeper beam assembly comprises an upper cover plate, a lower cover plate and a plurality of webs, the upper cover plate and the lower cover plate are arranged in parallel relatively, and the webs are connected between the upper cover plate and the lower cover plate at intervals; the method comprises the steps that (1) grooves are formed in the edge, close to the upper cover plate, of the web plate and the edge, close to the lower cover plate, of the web plate; (2) preparing for laser backing welding, and positioning, clamping and aligning the upper cover plate, the lower cover plate and the web plate; (3) laser welding is conducted; the step (3) comprises the steps that S31, laser welding parameters are set; s32, laser backing welding is carried out; (4) the plate is subjected to cover face filling welding through electric arc welding; and (5) welding seams are cleaned. According to the welding method for the sleeper beam assembly of the railway vehicle, it can be guaranteed that the quality of welded plates is good, and the dimensional precision after welding is high.

Description

Technical Field

[0001] The invention belongs to the technical field of welding, and in particular relates to a welding method for a rail vehicle bolster assembly. Background Art

[0002] With the rapid development of rail vehicle processing and manufacturing technology, the train load-bearing capacity and running speed have been greatly improved. At the same time, during the operation of the train, especially under high speed and heavy load conditions, higher requirements are placed on the strength and rigidity of key load-bearing components such as bogies and car body underframes that bear strong vibration and impact loads. Therefore, in order to ensure the safe and stable operation of the train, in the manufacturing of key load-bearing components of rail vehicles, more and more plates with higher strength grades are used, and the welding quality requirements are also getting higher and higher.

[0003] At present, in the rail vehicle industry, arc welding is often used for the base and cover welding of carbon steel plates with a thickness of 6 mm or more. With this welding process, there are more filler welds, a large heat-affected zone, a large shrinkage after the weld solidifies, and uncontrollable precision; moreover, the plates used in rail vehicles are mostly long, and operators cannot complete the welding in one go, resulting in inconsistent weld sizes in the structure between the first weld and the second end weld, which requires further grinding, which is time-consuming and labor-intensive; with arc welding as the base weld, the back of the plate has a poor molding quality.

[0004] Therefore, developing a welding method for rail vehicle sleeper beam components that can ensure good quality of welded plates and high dimensional accuracy after welding is a technical problem that needs to be solved urgently. Summary of the invention

[0005] The object of the present invention is to provide a welding method for a rail vehicle bolster assembly to solve the problems of low welding quality of the plate back plate and low dimensional accuracy after welding caused by the use of arc welding for base welding of the plate in the prior art.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: The present invention provides a welding method for a rail vehicle bolster assembly, which comprises: The bolster comprises an upper cover plate, a lower cover plate and a plurality of web plates, wherein the upper cover plate and the lower cover plate are arranged relatively parallel, and a plurality of web plates are connected between the upper cover plate and the lower cover plate at intervals; Step (1): opening grooves at the edge of the web close to the upper cover plate and the edge of the lower cover plate; Step (2): preparing for laser bottom welding, positioning, clamping and aligning the upper cover plate, the lower cover plate and the web plate; Step (3): laser welding; the step (3) comprises: S31: Laser welding parameter settings: The laser welding equipment is a fiber laser, the laser welding power is 1500W-2000W, the laser scanning width is 2.5mm to 4mm, the scanning speed is 350mm / s, the welding speed is 60cm / min, the shielding gas flow rate is 5L / min, and the welding gun angle is 70° to 80°; S32: Laser base welding; Step (4): arc welding is used to perform cover and fill welding on the plate; Step (5): Clean the weld.

[0007] In some embodiments of the present application, step (4) includes: S41: arc welding parameter setting; S42: Arc welding cap filling welding; S43: Arc welding cap filler weld inspection.

[0008] In some embodiments of the present application, the S42 includes: multi-layer arc welding cap filling welding; The first layer of arc welding cap weld welding current 240A, voltage 25V, welding speed 5.5mm / s; The remaining layers of arc welding cover weld welding current 250A, voltage 25V, welding speed 5.5mm / s; During the arc welding cap filling welding process, the shielding gas flow rate is 18L / min, and the metal transfer form adopts pulse transfer method.

[0009] In some embodiments of the present application, the welding wire for arc welding is G46 4M21Z3CrNiCu, and the diameter of the welding wire is 1.2 mm.

[0010] In some embodiments of the present application, step (1) includes: S11: groove marking, using a marking tool to mark the groove cutting line on the web; S12: Bevel cutting, grinding the bevel with a grinding wheel, grinder or hand tool to remove burrs or irregularities generated during the cutting process; S13: Cleaning the groove: use acetone to clean the oxide or oil on the groove surface; S14: Bevel inspection: use measuring tools to check whether the size and angle of the bevel meet the design requirements.

[0011] In some embodiments of the present application, before the laser welding in step (3), when the materials of the web, the upper cover plate and the lower cover plate are high carbon steel or alloy steel, the groove needs to be preheated.

[0012] In some embodiments of the present application, the groove includes a V-shaped groove, a single-sided V-shaped groove, a U-shaped groove, a double-sided groove, or a J-shaped groove.

[0013] In some embodiments of the present application, after step (5), step (6) is performed, and step (6) includes heat treatment, in which the bolster component is heat treated.

[0014] In some embodiments of the present application, after the S32: laser root welding, S33: laser root welding weld inspection is performed.

[0015] In some embodiments of the present application, in step (2), the assembly gap between the groove of the web and the upper cover plate and the lower cover plate is less than or equal to 0.5 mm.

[0016] Compared with the prior art, the advantages and positive effects of the present invention are: By opening a breach at the edge of the web close to the upper cover plate and the edge of the lower cover plate, laser base welding is used to perform base welding on the web, the upper cover plate and the lower cover plate. The laser welding power is 1500W to 2000W, the laser scanning width is 2.5mm to 4mm, the scanning speed is 350mm / s, the welding speed is 60cm / min, the shielding gas flow is 5L / min, and the welding gun angle is 70° to 80°; the welding quality of laser base welding can be guaranteed and the generation of welding pores can be reduced. After the web is welded to the upper cover plate and the lower cover plate, a cavity is formed. The back side of the web after welding is located in the cavity. Since laser base welding is used instead of arc welding, it can ensure that the welding back side will have poor welding quality and need to be polished. If the web is base welded by arc welding, there is no grinding space. The above problems do not exist when laser base welding is used.

[0017] After reading the specific embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become more clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 This is one of the overall structural schematic diagrams of an embodiment of the rail vehicle bolster assembly proposed by the present invention; Figure 2 This is the second schematic diagram of the overall structure of an embodiment of the rail vehicle bolster assembly proposed by the present invention; Figure 3 Schematic diagram of a web V-shaped groove of an embodiment of a rail vehicle bolster assembly proposed by the present invention; Figure 4 Schematic diagram of a web J-shaped groove of an embodiment of a rail vehicle bolster assembly proposed by the present invention; In the figure, 110, upper cover; 120, lower cover; 130, belly plate; 140, cavity; 151. V-shaped groove; 152, J-shaped groove; 210, first laser bottom welding area; 220, first arc cap welding area; 230, second arc cap welding area; 240, second laser bottom welding area; 250, third arc cap welding area; 260. Fourth arc cover welding area. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0023] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] In the present invention, unless otherwise clearly stipulated and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0025] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0026] In some embodiments of the present application, a welding method for a rail vehicle bolster assembly is provided, which is applied to welding the bolster assembly.

[0027] like Figure 1 , Figure 2 As shown, the bolster comprises an upper cover plate 110 , a lower cover plate 120 and a plurality of web plates 130 .

[0028] The upper cover plate 110 and the lower cover plate 120 are arranged relatively parallel.

[0029] The number of the webs 130 is generally multiple. The multiple webs 130 are used to support the upper cover plate 110 and the lower cover plate 120.

[0030] Specifically, a plurality of webs 130 are connected between the upper cover plate 110 and the lower cover plate 120 at intervals.

[0031] Specifically, the plurality of webs 130 are vertically arranged relative to the upper cover plate 110 and the lower cover plate 120 .

[0032] Specifically, a plurality of webs 130 are arranged in parallel.

[0033] After the plurality of webs 130 are welded to the upper cover plate 110 and the lower cover plate 120 , a cavity 140 is formed. The welded back side of the webs 130 is located in the cavity 140 , and it is not easy to perform operations such as grinding.

[0034] The welding method of the rail vehicle bolster assembly is used for welding the upper edge of the web 130 and the upper cover plate 110 , and for welding the lower edge of the web 130 and the lower cover plate 120 .

[0035] In some embodiments of the present application, a method for welding a rail vehicle bolster assembly includes: Step (1): a groove is formed on the edge of the web 130 close to the upper cover plate 110 ; a groove is formed on the edge of the web 130 close to the lower cover plate 120 .

[0036] Specifically, the groove can be one or more of a V-shaped groove, a single-sided V-shaped groove, a U-shaped groove, a double-sided groove or a J-shaped groove.

[0037] Among them, in the welding process, J-shaped groove and single-sided V-shaped groove are two common groove forms, each of which has different advantages and disadvantages and is suitable for different application scenarios.

[0038] Providing a J-groove at the edge of the web 130 allows for less welding material to be used. The J-groove generally requires less filler material because the volume of the groove is smaller, which can reduce material costs. The weld quality using the J-groove is better; at the same time, the shape of the J-groove helps to achieve good fusion and reduce welding defects such as pores and slag inclusions. Using the J-groove generally results in less welding deformation. Since the welding material and heat input are less, the deformation of the workpiece after the J-groove welding is generally smaller. The J-groove is particularly suitable for thicker plates because it can effectively control welding deformation and stress.

[0039] A single-sided V-shaped groove is provided at the edge of the web 130. The single-sided V-shaped groove is easy to process and can be realized by conventional cutting equipment, which is suitable for on-site construction. The single-sided V-shaped groove has a wide range of applications and is suitable for plates of various thicknesses, especially medium-thickness workpieces. The single-sided V-shaped groove has good welding operability and provides good visibility and operating space, which is convenient for welders to perform welding operations.

[0040] Since the thickness of the upper cover plate 110 , the lower cover plate 120 and the web plate 130 are all medium-thick plates, the type of groove can be selected according to their thickness.

[0041] J-grooves are typically used for thicker materials, while single V-grooves are suitable for medium thickness materials.

[0042] After performing step (1) to open the groove, perform step (2): prepare for laser bottom welding, and position, clamp and align the upper cover plate 110, the lower cover plate 120 and the web plate 130.

[0043] Laser bottom welding is adopted, and the assembly gap is controlled within the range of 0 to 0.5mm. Due to the small assembly gap, the welding filling is small, the heat impact is small, the shrinkage of the welding material after solidification is small, and the precision is easier to control. It can improve the overall precision of the bolster after welding.

[0044] At the same time, laser bottom welding is used to replace the original arc welding bottom welding, which can ensure the welding quality of the back side of the web 130 after bottom welding without further grinding and other treatments, thereby avoiding the problem that there is no grinding space due to the back side being located in the cavity 140.

[0045] After assembly is completed, positioning, clamping and alignment are performed, step (3): laser welding.

[0046] Step (3): Laser welding, including the following steps: S31: Laser welding parameter settings: The laser welding equipment is a fiber laser, the laser welding power is 1500W-2000W, the laser scanning width is 2.5mm to 4mm, the scanning speed is 350mm / s, the welding speed is 60cm / min, the shielding gas flow rate is 5L / min, and the welding gun angle is 70° to 80°; Specifically, the shielding gas for laser welding may be pure argon shielding welding.

[0047] Using pure argon as the shielding gas and keeping the welding gun angle between 70° and 80° can reduce the generation of welding porosity.

[0048] S32: Laser base welding; S33: Laser base welding weld inspection: After completing base welding, check the appearance and quality of the weld to ensure that there are no obvious defects such as pores, cracks or incomplete penetration; internal defects such as pores, cracks or lack of fusion can also be checked by non-destructive testing methods such as radiography.

[0049] After the base welding is performed by laser welding and step (3) is completed, step (4) is performed: arc welding is used to perform cover filling welding on the plate: S41: arc welding parameter setting; Select appropriate welding current and voltage according to the thickness of the steel plate, welding position and welding materials. Medium and thick steel plates usually require higher currents. Adjust the welding speed to ensure good weld formation and penetration. Select appropriate welding rod or wire materials to match the parent material to ensure welding quality.

[0050] The arc welding wire is G46 4M21Z3CrNiCu, and the diameter of the wire is 1.2mm. The arc welding shielding gas is 80% argon and 20% carbon dioxide.

[0051] S42: Arc welding cover filling welding; S42 includes: multi-layer arc welding cover filling welding; the first layer of arc welding cover weld welding current is 240A, voltage is 25V, welding speed is 5.5mm / s; the remaining layers of arc welding cover weld welding current is 250A, voltage is 25V, welding speed is 5.5mm / s; during the arc welding cover filling welding process, the shielding gas flow rate is 18L / min, and the metal transition form adopts pulse transition method.

[0052] Depending on the depth and width of the groove, multiple layers and passes may be required. After each layer of welding, remove the slag and oxides. For example, you can use welding methods such as straight line method, sawtooth method or circle method to obtain a good weld appearance.

[0053] Regardless of the groove form, the heat input required for the first layer of arc welding near the laser base welding is relatively small. Therefore, the current of the first layer of arc welding is smaller than the current values ​​of the remaining subsequent layers.

[0054] S43: Arc welding cap filler weld inspection.

[0055] S43 includes the following steps: Check the appearance and quality of the weld to ensure there are no obvious defects such as pores, cracks or lack of penetration; you can also use non-destructive testing methods such as radiography to check for internal defects such as pores, cracks or lack of fusion.

[0056] like Figure 3 As shown, the groove is a V-shaped groove 151. Laser root welding forms a first laser root welding area 210, and then a first arc cover welding area 220 is performed, and then a second arc cover welding area 230 is performed.

[0057] like Figure 4 As shown, the groove is a J-shaped groove 152. Laser root welding forms a second laser root welding area 240, and then a third arc cap welding area 250 is performed, and then a fourth arc cap welding area 260 is performed.

[0058] After completing step (4), proceed to step (5), which includes: cleaning the weld, using appropriate tools to clean the weld surface, and removing slag, spatter and oxides.

[0059] After completing step (5), step (6) is performed, which includes: heat treatment, heat treatment of the bolster component. According to the characteristics of the bolster component material, it is determined whether to heat treat the bolster component to eliminate stress and improve material properties.

[0060] After completing step (6), proceed to step (7), which includes: adjusting welding parameters and operation methods according to the welding results to optimize welding quality and efficiency. Verifying the optimal selection of the above welding process parameters, the optimal parameters, and using the optimal selection as the welding process parameters of the final product.

[0061] Step (7) includes the following tests: About non-destructive testing (NDT) testing methods: (1) Ultrasonic testing (UT): Use high-frequency sound waves to detect internal defects in welds, such as lack of fusion, lack of penetration, and internal cracks.

[0062] (2) Radiographic testing (RT): Use X-rays or gamma rays to capture images of the internal structure of the weld to identify internal defects.

[0063] (3) Magnetic Particle Testing (MT): Applicable to ferromagnetic materials, by magnetizing the weld and using magnetic particles to detect surface and near-surface defects.

[0064] (4) Penetrant testing (PT): Applicable to non-ferromagnetic materials, which detects surface defects through penetrant fluid.

[0065] About the detection method of mechanical performance test: (1) Tensile test: Evaluate the tensile strength of the welded joint to ensure it meets the design requirements.

[0066] (2) Bending test: Test the plastic deformation capacity of the weld and check the toughness and ductility of the weld (3) Impact test: Measures the toughness of welds at low temperatures or high strain rates, usually using the Charpy impact test.

[0067] (4) Hardness test: Measure the hardness distribution of the weld and its heat-affected zone to evaluate the impact of welding thermal cycle.

[0068] About the detection method of metallographic analysis: Observe the microstructure of the weld through a microscope, analyze the weld metallographic structure, and check whether there are adverse microstructural changes, such as coarse grains, segregation, etc.

[0069] About the detection method of fatigue test: Evaluate the durability of welded joints under cyclic loading, particularly in structures used under dynamic loading conditions.

[0070] About the detection method of corrosion test: Corrosion tests are performed on welded joints to evaluate their corrosion resistance under specific environmental conditions.

[0071] Wherever possible, the various aspects and features described and shown in the specification may be applied separately and these separate aspects may be made the subject of divisional applications.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A welding method for a rail vehicle bolster assembly, characterized in that: include: The bolster comprises an upper cover plate, a lower cover plate and a plurality of web plates, wherein the upper cover plate and the lower cover plate are arranged relatively parallel, and a plurality of web plates are connected between the upper cover plate and the lower cover plate at intervals; Step (1): opening grooves at the edge of the web close to the upper cover plate and the edge of the lower cover plate; Step (2): preparing for laser bottom welding, positioning, clamping and aligning the upper cover plate, the lower cover plate and the web plate; Step (3): laser welding; the step (3) comprises: S31: Laser welding parameter settings: The laser welding equipment is a fiber laser, the laser welding power is 1500W to 2000W, the laser scanning width is 2.5mm to 4mm, the scanning speed is 350mm / s, the welding speed is 60cm / min, the shielding gas flow rate is 5L / min, and the welding gun angle is 70° to 80°; S32: Laser base welding; Step (4): arc welding is used to perform cover and fill welding on the plate; Step (5): Clean the weld.

2. The welding method for a rail vehicle bolster assembly according to claim 1, characterized in that: The step (4) comprises: S41: arc welding parameter setting; S42: Arc welding cap filling welding; S43: Arc welding cap filler weld inspection.

3. The welding method for the rail vehicle bolster assembly according to claim 2, characterized in that: The S42 includes: multi-layer arc welding cap filling welding; The first layer of arc welding cap weld welding current 240A, voltage 25V, welding speed 5.5mm / s; The remaining layers of arc welding cover weld welding current 250A, voltage 25V, welding speed 5.5mm / s; During the arc welding cap filling welding process, the shielding gas flow rate is 18L / min, and the metal transfer form adopts pulse transfer method.

4. The welding method for a rail vehicle bolster assembly according to claim 1, characterized in that: The welding wire for arc welding is G46 4M21Z3CrNiCu, and the wire diameter is 1.2mm.

5. The welding method for a rail vehicle bolster assembly according to claim 1, characterized in that: The step (1) comprises: S11: groove marking, using a marking tool to mark the groove cutting line on the web; S12: Bevel cutting, grinding the bevel with a grinding wheel, grinder or hand tool to remove burrs or irregularities generated during the cutting process; S13: Cleaning the groove: use acetone to clean the oxide or oil on the groove surface; S14: Bevel inspection: use measuring tools to check whether the size and angle of the bevel meet the design requirements.

6. The welding method for a rail vehicle bolster assembly according to claim 5, characterized in that: Before the laser welding in step (3), when the web, the upper cover plate and the lower cover plate are made of high carbon steel or alloy steel, the groove needs to be preheated.

7. The welding method for a rail vehicle bolster assembly according to claim 5, characterized in that: exist The groove includes a V-shaped groove, a single-sided V-shaped groove, a U-shaped groove, a double-sided groove, or a J-shaped groove.

8. The method for welding a rail vehicle bolster assembly according to claim 1, characterized in that: After step (5), step (6) is performed, wherein step (6) includes heat treatment, in which the bolster component is heat treated.

9. The method for welding a rail vehicle bolster assembly according to claim 1, characterized in that: After the laser root welding step S32 , the laser root welding weld inspection step S33 is performed.

10. The welding method for a rail vehicle bolster assembly according to claim 1, characterized in that: In the step (2), the assembly gap between the groove of the web and the upper cover plate and the lower cover plate is less than or equal to 0.5 mm.

Images