Hydraulic support main rib assembly splicing method using nano-coated steel plate

Abstract

The application discloses a kind of hydraulic support main reinforcement assembly stitch welding methods using nano coating steel plate, it is related to welding technical field, according to drawing, draw the weld line of position of the part needing to be welded on main reinforcement plate and backing plate, according to the weld line of position drawn on the surface of main reinforcement plate and reinforcing plate, first using hand-held laser derusting equipment to the nano coating within 20mm range on both sides of weld line preliminary cleaning, then using sanding machine to manually polish, remove the residue on the surface of steel plate after laser derusting, draw reinforcing plate position line on main reinforcement plate, place reinforcing plate on main reinforcement plate, adjust reinforcing plate position, manually position welding, wherein reinforcing plate perimeter within 1m is evenly positioned 3 times, reinforcing plate perimeter exceeds 1m and is evenly positioned 4-5 times.The application reduces the probability that nano coating is decomposed by heating during welding and causes backing welding porosity defects and cutting fluid residue in weld causes welding porosity, to ensure welding quality.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and more specifically to a method for welding the main rib assembly of a hydraulic support using a nano-coated steel plate. Background Technology

[0002] Hydraulic supports, as the main support equipment in fully mechanized coal mining equipment, are customized products characterized by numerous types, large welding volumes, harsh service conditions, and complex stress. The structural components of hydraulic supports are mainly welded from high-strength steel plates. The shield beam, top beam, and base are the main structural components of the hydraulic support, composed of main rib assemblies, rib plates, and cover plates. The main rib assembly is a crucial component of the hydraulic support structure, including main rib plates and reinforcing plates. The welds on the main rib assembly include fillet welds between the main rib plates and reinforcing plates, and single V-shaped 40° bevel welds formed by the 40° bevel cut on the reinforcing plate fitting against the main rib plate. Both types of welds require multi-layer, multi-pass welding. The common processing flow for the main rib assembly is: main rib assembly assembly, tack welding, plate processing, and main rib assembly welding.

[0003] To slow down the corrosion rate of hydraulic support structural components in mines and extend their service life, some products require high-strength steel plates with a nano-anti-rust coating. Nano-coated steel plates are steel plates with nano-sized organic coatings sprayed on both sides before leaving the factory. When using this steel plate to weld the main rib components of hydraulic supports according to the above method, defects such as porosity and slag inclusions often occur during welding due to the high organic content in the nano-coating. Furthermore, the smooth surface of the nano-coating makes it easy for impurities such as cutting fluid to remain in the gap near the weld between the main rib plate and the reinforcing plate during plate processing. If the main rib components are processed before welding, it will seriously threaten the welding quality. However, if the main rib components are welded first and then the plates are processed, it is easy to cause excessive deformation of the main rib components after welding, affecting the processing accuracy of the plates and making it impossible to guarantee dimensional accuracy.

[0004] Therefore, it is necessary to propose a welding method for the main rib assembly of a hydraulic support using nano-coated steel plates to solve the above problems. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] The purpose of this invention is:

[0007] To address the issues that arise during welding due to the high organic content in nano-coatings, which often leads to defects such as porosity and slag inclusions, and the fact that the smooth surface of the nano-coating makes it easy for impurities such as cutting fluid to remain in the gaps near the welds between the main stiffening plates and reinforcing plates in the main stiffening components during plate processing, thus posing a serious threat to welding quality.

[0008] (II) Technical Solution

[0009] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0010] A method for welding the main rib assembly of a hydraulic support using nano-coated steel plates includes the following steps:

[0011] S1: Marking lines, draw the weld seam positions of the parts that need to be welded on the main stiffening plate and the reinforcing plate according to the drawings;

[0012] S2: Grinding. Following the weld seam position lines drawn in step S1 on the surface of the main stiffening plate and reinforcing plate, first use a handheld laser rust removal device to preliminarily clean the nano-coating within a 20mm range on both sides of the weld seam position lines, and then use a grinding wheel for manual grinding to remove the residue on the steel plate surface after laser rust removal.

[0013] S3: Assembly. Mark the position lines of the reinforcing plate on the main stiffening plate, place the reinforcing plate on the main stiffening plate, adjust the position of the reinforcing plate, and perform manual positioning welding. There are 3 uniform positioning welds within 1m of the reinforcing plate circumference, and 4-5 uniform positioning welds for the reinforcing plate circumference exceeding 1m.

[0014] S4: Root pass welding. Place the main rib assembly on the welding platform and use a welding robot to perform root pass welding on the weld seam of the main rib assembly. After welding, visual inspection is used to check for defects in the root pass weld. If there are porosity defects, rework is carried out directly.

[0015] S5: Plate processing. After the workpiece has cooled to room temperature, fix the main rib assembly on the platform of the machining center. Bor or drill the machining holes of the main rib assembly. After processing, use a flame gun to heat the area within 20mm on both sides of the root weld to evaporate the oil and cutting fluid.

[0016] S6: Filling and capping welding. Place the main rib assembly on the welding platform and use a welding robot to perform overall filling and capping welding layer by layer. After each layer of weld is completed, visual inspection is used to check the defects of that layer of weld. If there are porosity defects, they are directly reworked.

[0017] S7: Spray nano paint with the same composition as the nano coating on the steel plate within 20mm of the weld seam on the main rib assembly;

[0018] Furthermore, in step S3, the tack welding uses ER50-6 φ1.2mm welding wire, welding current 260-280A, voltage 30-32V, welding speed 350-400mm / min, and each tack weld is 300-500mm long and 3-4mm high.

[0019] Furthermore, step S4 employs Ar + 20% CO2 mixed gas shielded welding with a solid core welding wire of φ1.6mm diameter. The welding parameters are as follows: welding current 330-350A, voltage 26-28V, wire feed speed 6m / min, welding speed 45cm / min, transverse sinusoidal oscillation of the welding wire end 3-4mm, welding wire extension 17-22mm, and shielding gas flow rate 20-25L / min. For fillet welds, the robot's welding torch is at a 45-50° angle to the main stiffening plate. For 40° single-sided bevel welds, the robot's welding torch is at a 20-25° angle to the straight edge of the bevel weld.

[0020] Furthermore, in step S6, welding is performed using a mixed gas shielded welding of Ar + 20% CO2, with a solid core welding wire of φ1.6mm diameter. The filler and cover parameters are as follows: welding current 440-480A, voltage 30-33V, wire feed speed 8-10m / min, welding speed 40-50cm / min, transverse sinusoidal oscillation of the welding wire end 1-4mm, welding wire extension 20-25mm, and shielding gas flow rate 20-25L / min. For fillet welds, the robot's welding torch is at an angle of 45°±2° to the main stiffening plate. For 40° single-sided bevel welds, the robot's welding torch is at an angle of 20°±2° to the straight edge of the bevel weld.

[0021] (III) Beneficial Effects

[0022] The beneficial effects of this invention are as follows:

[0023] 1. This invention ensures the weld quality of the main rib assembly, significantly reduces welding defects such as porosity and slag inclusion caused by the use of nano-coated steel plates, improves the service life of hydraulic support structural components, and reduces stress corrosion of hydraulic supports during service.

[0024] 2. This invention reduces the probability of defects in the root pass weld caused by thermal decomposition of the nano-coating during welding, as well as the probability of weld porosity caused by residual cutting fluid in the weld bead, thus ensuring welding quality.

[0025] 3. This invention optimizes the welding sequence of the robot and the processing sequence of the sheet metal, and invents reasonable welding parameters for the robot and innovates the pointing of the robot's welding torch, which effectively reduces the probability of porosity caused by incomplete removal of the nano-coating near the weld during welding.

[0026] 4. In this invention, a smaller welding heat input is used for the initial welding, and the filler and cover welding are performed after the plate is processed. This avoids the serious welding deformation caused by excessive welding of the main rib components, which would affect the consistency of the plate processing accuracy.

[0027] 5. For hydraulic supports that require multi-layer and multi-pass welding, the robot performs the root pass, fill pass, and cover pass welding as a whole according to the number of weld layers. After each layer is welded, the weld defects are checked. This effectively avoids the problem that in traditional welding methods, when multiple layers and multiple passes are welded as a whole, internal weld defects are not easy to find, and the repair of multiple layers and multiple passes is difficult.

[0028] 6. The present invention adopts a method of first drawing the weld position line on the workpiece according to the drawing, and then grinding the inner and outer sides of the weld on the workpiece. This method not only accurately determines the area of ​​the weld that needs to be ground, but also avoids excessive damage to the nano-coating surface that does not need to be welded. In addition, it effectively avoids the traditional method of assembling the parts into a component first and then grinding the weld area, which would result in the nano-coating in the weld depth of the workpiece fitting part not being removed, thus causing welding defects. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the main rib assembly structure of the present invention;

[0030] Figure 2 This is a schematic diagram showing the location of the weld seam on the main rib assembly of the present invention;

[0031] Figure 3 This is a schematic diagram of the main stiffening plate of the present invention;

[0032] Figure 4 This is a schematic diagram of the reinforcing plate of the present invention;

[0033] Figure 5 This is a schematic diagram of the grinding position in this invention;

[0034] Figure 6 This is a schematic diagram of the welding torch angle of the present invention.

[0035] Figure 7 This is a schematic diagram of the welding sequence of the robot according to the present invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Please refer to Figures 1-7. A method for welding the main rib assembly of a hydraulic support using nano-coated steel plates includes the following steps:

[0038] S1: Marking lines, draw the weld seam positions of the parts that need to be welded on the main stiffening plate and the reinforcing plate according to the drawings;

[0039] S2: Grinding. Following the weld seam position lines drawn in step S1 on the surface of the main stiffening plate and reinforcing plate, first use a handheld laser rust removal device to preliminarily clean the nano-coating within a 20mm range on both sides of the weld seam position lines, and then use a grinding wheel for manual grinding to remove the residue on the steel plate surface after laser rust removal.

[0040] S3: Assembly. Mark the position lines of the reinforcing plate on the main stiffening plate, place the reinforcing plate on the main stiffening plate, adjust the position of the reinforcing plate, and perform manual positioning welding. There are 3 uniform positioning welds within 1m of the reinforcing plate circumference, and 4-5 uniform positioning welds for the reinforcing plate circumference exceeding 1m.

[0041] S4: Root pass welding. Place the main rib assembly on the welding platform and use a welding robot to perform root pass welding on the weld seam of the main rib assembly. After welding, visual inspection is used to check for defects in the root pass weld. If there are porosity defects, rework is carried out directly.

[0042] S5: Plate processing. After the workpiece has cooled to room temperature, fix the main rib assembly on the platform of the machining center. Bor or drill the machining holes of the main rib assembly. After processing, use a flame gun to heat the area within 20mm on both sides of the root weld to evaporate the oil and cutting fluid.

[0043] S6: Filling and capping welding. The main rib assembly is placed on the welding platform, and a welding robot is used to perform overall filling and capping welding layer by layer. After each layer of weld is completed, the defects of the root weld are visually inspected. If there are porosity defects, they are directly reworked. The process flow of the main rib assembly is changed from grinding → assembly → plate processing → welding to grinding → assembly → root welding → plate processing → filling and capping welding. After assembly, the root welding is performed first, then the assembly is processed, and finally the filling and capping welding is performed. This avoids the residue of cutting fluid in the gap between the main rib plate and the reinforcing plate. At the same time, the weld is heated after the root welding to ensure that there is no cutting fluid inside the weld during the filling and capping welding, thus ensuring the quality of the welding.

[0044] S7: Spray a nano-paint with the same composition as the nano-coating on the steel plate within a 20mm radius around the weld seam on the main rib assembly. Grinding of the parts has been changed from only grinding the main rib plate to grinding the nano-coating on all areas where the main rib plate and reinforcing plate have weld seams. Furthermore, the grinding area has been increased from 20mm to both sides of the weld seam, thus expanding the grinding area. Simultaneously, by optimizing the welding position and parameters for manual tack welding (appropriately reducing the welding current and increasing the arc voltage), the weld penetration depth has been reduced while improving the arc initiation smoothness, preventing the formation of internal porosity in the weld seam during tack welding.

[0045] In step S3, the tack welding uses ER50-6 φ1.2mm welding wire, welding current 260-280A, voltage 30-32V, welding speed 350-400mm / min, and each tack weld is 300-500mm long and 3-4mm high.

[0046] Step S4 employs Ar + 20% CO2 mixed gas shielded welding with a φ1.6mm diameter solid welding wire. Welding parameters are: welding current 330-350A, voltage 26-28V, wire feed speed 6m / min, welding speed 45cm / min, transverse sinusoidal oscillation of the welding wire end 3-4mm, welding wire extension 17-22mm, and shielding gas flow rate 20-25L / min. For fillet welds: the robot's welding torch is at a 45-50° angle to the main stiffening plate. For 40° single-sided bevel welds, the robot's welding torch is at a 20-25° angle to the straight edge of the bevel weld.

[0047] In step S6, welding is performed using a mixed gas shielded by Ar + 20% CO2, with a solid core welding wire of φ1.6mm diameter. The fillet and cover parameters are as follows: welding current 440-480A, voltage 30-33V, wire feed speed 8-10m / min, welding speed 40-50cm / min, transverse sinusoidal oscillation of the welding wire end 1-4mm, welding wire extension 20-25mm, and shielding gas flow rate 20-25L / min. For fillet welds: the robot's welding torch is at an angle of 45°±2° to the main stiffening plate. For 40° single-sided bevel welds, the robot's welding torch is at an angle of 20°±2° to the straight edge of the bevel weld.

[0048] In summary, this invention ensures the weld quality of the main rib assembly, significantly reduces welding defects such as porosity and slag inclusions caused by the use of nano-coated steel plates, improves the service life of hydraulic support structural components, and reduces stress corrosion of hydraulic supports during service.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0050] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for welding the main rib assembly of a hydraulic support using nano-coated steel plates, characterized in that: Includes the following steps: S1: Marking lines, draw the weld seam positions of the parts that need to be welded on the main stiffening plate and the reinforcing plate according to the drawings; S2: Grinding. Following the weld seam position lines drawn in step S1 on the surface of the main stiffening plate and reinforcing plate, first use a handheld laser rust removal device to preliminarily clean the nano-coating within a 20mm range on both sides of the weld seam position lines, and then use a grinding wheel for manual grinding to remove the residue on the steel plate surface after laser rust removal. S3: Assembly. Mark the position lines of the reinforcing plate on the main stiffening plate, place the reinforcing plate on the main stiffening plate, adjust the position of the reinforcing plate, and perform manual positioning welding. There are 3 uniform positioning welds within 1m of the reinforcing plate circumference, and 4-5 uniform positioning welds for the reinforcing plate circumference exceeding 1m. S4: Root pass welding. Place the main rib assembly on the welding platform and use a welding robot to perform root pass welding on the weld seam of the main rib assembly. After welding, visual inspection is used to check for defects in the root pass weld. If there are porosity defects, rework is carried out directly. S5: Plate processing. After the workpiece has cooled to room temperature, fix the main rib assembly on the platform of the machining center. Bor or drill the machining holes of the main rib assembly. After processing, use a flame gun to heat the area within 20mm on both sides of the root weld to evaporate the oil and cutting fluid. S6: Filling and capping welding. Place the main rib assembly on the welding platform and use a welding robot to perform overall filling and capping welding layer by layer. After each layer of weld is completed, visual inspection is used to check the defects of that layer of weld. If there are porosity defects, they are directly reworked. S7: Spray nano paint with the same composition as the nano coating on the steel plate within 20mm around the weld seam on the main rib assembly.

2. The welding method for the main rib assembly of a hydraulic support using nano-coated steel plates according to claim 1, characterized in that: In step S3, the tack welding uses ER50-6 φ1.2mm welding wire, welding current 260-280A, voltage 30-32V, welding speed 350-400mm / min, and each tack weld is 300-500mm long and 3-4mm high.

3. The welding method for the main rib assembly of a hydraulic support using nano-coated steel plate according to claim 1, characterized in that: Step S4 uses Ar + 20% CO2 mixed gas shielded welding with a solid core wire of φ1.6mm diameter. Welding parameters are as follows: welding current 330-350A, voltage 26-28V, wire feed speed 6m / min, welding speed 45cm / min, transverse sinusoidal oscillation of the wire end 3-4mm, wire extension 17-22mm, shielding gas flow rate 20-25L / min. For fillet welds, the robot's welding torch is at a 45-50° angle to the main stiffening plate. For 40° single-sided bevel welds, the robot's welding torch is at a 20-25° angle to the straight edge of the bevel weld.

4. The welding method for the main rib assembly of a hydraulic support using nano-coated steel plate according to claim 1, characterized in that: In step S6, welding is performed using a mixed gas shielded by Ar + 20% CO2, with a solid core welding wire of φ1.6mm diameter. The filler and cover parameters are as follows: welding current 440-480A, voltage 30-33V, wire feed speed 8-10m / min, welding speed 40-50cm / min, transverse sinusoidal oscillation of the welding wire end 1-4mm, welding wire extension 20-25mm, and shielding gas flow rate 20-25L / min. For fillet welds, the robot's welding torch is at an angle of 45°±2° to the main stiffening plate. For 40° single-sided bevel welds, the robot's welding torch is at an angle of 20°±2° to the straight edge of the bevel weld.

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