2205 duplex stainless steel plate electric arc additive repairing method

Abstract

The invention aims to provide an electric arc additive repairing method for a 2205 duplex stainless steel plate, which belongs to the technical field of metal repairing processing, and comprises the following steps: pretreating a to-be-repaired area of a 2205 duplex stainless steel plate substrate; the method comprises the following steps: constructing an original data model through three-dimensional modeling software according to the length, width and height of a 2205 duplex stainless steel plate substrate, assigning a reference point near a to-be-repaired area, performing multi-directional scanning from the reference point through a three-dimensional scanner to obtain point cloud data, extracting feature points to establish a wear model, collecting three-dimensional cloud pictures of the substrate and the to-be-repaired area, and performing three-dimensional repair on the matrix and the to-be-repaired area. Performing hierarchical slicing on the to-be-repaired area, and calculating the length, width and height of the to-be-repaired area; setting process parameters of electric arc additive repair, and calculating a repair path; an electric arc is adopted as a heat source to implement additive repairing, and after repairing is completed, heat treatment, polishing post-treatment and detection work are sequentially carried out on a repairing area. The repairing method is simple, efficient and suitable for large-scale production.

Description

Technical Field

[0001] This invention belongs to the field of metal repair and processing technology, specifically relating to a method for arc additive repair of 2205 duplex stainless steel sheet. Background Technology

[0002] 2205 duplex stainless steel, with its excellent strength and superior corrosion resistance, is widely used in key fields such as petrochemicals and marine engineering. However, during actual service, 2205 duplex stainless steel sheets often suffer damage due to wear, corrosion, fatigue, and other factors, which adversely affects their normal use and structural safety. The traditional approach to damaged 2205 duplex stainless steel sheets is remelting, but this process results in waste.

[0003] For workpiece damage, there are two main repair methods in the existing technology: laser cladding repair and arc additive manufacturing repair. As an emerging manufacturing and repair technology, arc additive manufacturing technology has higher repair speed, lower equipment cost, and easier maintenance compared to laser cladding. Using an electric arc as a heat source and employing a layer-by-layer welding method to repair plates, it has advantages such as high deposition efficiency, high material utilization rate, and relatively low cost. However, there are no reports on its application in the repair of 2205 duplex stainless steel plates. Summary of the Invention

[0004] The purpose of this invention is to provide a method for arc additive repair of 2205 duplex stainless steel sheet. This method utilizes arc additive technology, using an electric arc as a heat source to fill the damaged area of ​​the 2205 duplex stainless steel sheet with duplex stainless steel welding wire, thereby improving the mechanical properties and corrosion resistance of the repaired area.

[0005] The present invention adopts the following technical solution: A method for arc additive repair of 2205 duplex stainless steel sheet includes the following steps: S1. Pre-treat the area to be repaired in the 2205 duplex stainless steel sheet substrate; S2. Using 3D modeling software, an original data model is constructed based on the length, width, and height of the 2205 duplex stainless steel sheet substrate. A reference point is specified near the area to be repaired of the 2205 duplex stainless steel sheet substrate. Then, a 3D scanner is used to scan from multiple directions from the reference point to obtain point cloud data, extract feature points to establish a wear model, collect 3D cloud maps of the 2205 duplex stainless steel sheet substrate and the area to be repaired, slice the area to be repaired into layers, and calculate the length, width, and height of the area to be repaired. S3. Set the process parameters for arc additive repair: wire feed speed 4-4.5m / min, welding speed 5-20m / min, overlap rate 30%-50%, welding voltage 15-20V, welding current 125-130A, shielding gas argon flow rate 10-15L / min; then use the above parameters to clad a single pass on the 2205 duplex stainless steel substrate, measure the width and height of the single pass, and calculate the repair path in combination with the repair process parameters; S4. Using an electric arc as a heat source to carry out additive repair, the repair work on the area to be repaired of 2205 duplex stainless steel plate is completed by depositing single-layer weld beads layer by layer. S5. After the repair is completed, heat treatment, grinding and post-treatment and testing are carried out on the repaired area in sequence.

[0006] Furthermore, the pretreatment method described in S1 is as follows: by cleaning and grinding, surface contaminants on the area to be repaired of the 2205 duplex stainless steel sheet substrate are removed to enhance bonding strength, optimize forming quality, reduce welding defects, and adapt to complex repair needs.

[0007] Furthermore, the calculation method for the repair path described in S3 is as follows: the repair method adopts a unidirectional cyclic repair; The total repair length is in mm, and the width of a single repair is 5-12 mm.

[0008] Furthermore, the repair material used in the arc additive repair is a duplex stainless steel welding wire with a diameter of 1.2-3.2 mm. The chemical composition of the duplex stainless steel welding wire is as follows: C≤0.03%, Mn≤2.00%, P≤0.03%, S≤0.03%, Si≤0.90%, Ni: 7.50-9.50%, Cr: 21.50-23.50%, Mo: 2.50-3.50%, N: 0.08-0.20%, and Fe as the balance.

[0009] Furthermore, the temperature of the electric arc used as a heat source in S4 is 1500℃. During the additive repair process, the welding current, welding voltage, and shielding gas flow rate parameters are monitored in real time to ensure the stability of the parameters. If any repair abnormality is found, the equipment parameters are adjusted in time or the additive repair process is stopped, and the equipment and process are checked.

[0010] Furthermore, the heat treatment, grinding and testing methods described in S5 are as follows: the repair area is sampled and heat-treated first to eliminate residual stress, adjust the two-phase ratio and improve the microstructure; then, flaw detection is performed, and its corrosion resistance is tested by electrochemical experiments; subsequently, the repair area is ground and polished to ensure that the surface roughness Ra≤3.2μm, so that its surface roughness meets the requirements for use.

[0011] Furthermore, the heat treatment method is as follows: samples are taken from the repaired surface and divided into three groups. Two of the groups are placed in a furnace at 1050°C and kept at that temperature for 13.5 min and 27 min respectively. They are then taken out and water-quenched for cooling, and compared with the third group that has not undergone heat treatment.

[0012] An electric arc additive repair method for 2205 duplex stainless steel sheets is disclosed, which is applied to the repair of large-size 2205 duplex stainless steel sheets. The large size is defined as the length of the 2205 duplex stainless steel sheet substrate to be repaired being ≥500mm, the width being ≥100mm, and the height being ≥50mm.

[0013] The beneficial effects of this invention are as follows: 1. This invention provides an operation method for repairing 2205 duplex stainless steel sheets using electric arc additive manufacturing technology.

[0014] 2. By optimizing the process parameters of electric arc additive repair, such as welding current, voltage, welding speed, wire feed speed, and interpass temperature, this invention can effectively control the heat input during the additive process, reduce the range of the heat-affected zone, and reduce the deformation and cracking tendency of the repaired sheet.

[0015] 3. This invention employs specific protective gas composition and flow rate, as well as synchronous wire feeding technology, to ensure the stability of the molten pool and the quality of the cladding metal during the additive manufacturing process, resulting in a more uniform microstructure and properties that are closer to the original material after repair.

[0016] 4. Post-repair heat treatment achieves a better two-phase balance, resulting in a repair layer with hardness and corrosion resistance closer to the substrate. This ensures the overall stability of the plate's performance and reduces secondary damage. Improved corrosion resistance is achieved through machining, which enhances surface quality and improves the overall performance of the repaired area, meeting the high quality requirements of actual engineering projects for the repair of 2205 duplex stainless steel plates.

[0017] 5. The repair method of the present invention is simple, efficient, and suitable for large-scale production. Attached Figure Description

[0018] Figure 1 A three-dimensional cloud image of the 2205 duplex stainless steel sheet substrate (a) and a schematic diagram of the repair path planning for the area to be repaired (b).

[0019] Figure 2 The images show the macroscopic morphology of the cladding single-pass (a) and the repaired 2205 duplex stainless steel substrate (b).

[0020] Figure 3 This is a microscopic morphology image of the interface section between the repaired arc additive repair layer and the 2205 duplex stainless steel sheet.

[0021] Figure 4 This is a microscopic morphology image of the arc additive repair layer of the sample that was not heat-treated after repair.

[0022] Figure 5 This is a microscopic morphology image of the arc additive repair layer of the sample after heat treatment for 13.5 min.

[0023] Figure 6 This is a microscopic morphology image of the three-arc additive repair layer of the sample after heat treatment for 27 minutes following repair.

[0024] Figure 7 It is the polarization curve of electrochemical corrosion between the repaired surface and the 2205 duplex stainless steel substrate. Detailed Implementation

[0025] To facilitate understanding of the present invention, the specific implementation methods of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Preferred embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0026] The various instruments, equipment, raw materials or reagents used in the embodiments of this invention are not subject to any special restrictions on their source. They are all conventional products that can be purchased through regular commercial channels and can be prepared according to conventional methods known to those skilled in the art.

[0027] A method for arc additive repair of 2205 duplex stainless steel sheet, specifically including the following steps: The first step is to select a piece of 2205 duplex stainless steel sheet with wear defects, measuring 500mm in length, 100mm in width, and 50mm in height. Use a grinding wheel to grind the defective area, removing surface oxide scale, oil, and impurities until a metallic luster is exposed, ensuring the defective surface is smooth. Then, clean the ground surface with acetone to remove any remaining oil and dust.

[0028] The second step involves using 3D modeling software to construct an original data model based on the dimensions of the board material (500mm long, 100mm wide, and 50mm high). Then, a 3D scanner is used to scan the reference points of the part to be repaired from multiple angles to obtain point cloud data. Feature points are extracted to establish a wear model. 3D cloud maps of the entire area and the repair area are collected. The repair area is then sliced ​​into layers, and the length, width, and height of the repaired area are calculated to be 110mm long, 100mm wide, and 5mm high.

[0029] The third step is to select welding wire that matches the chemical composition of 2205 duplex stainless steel as the repair material. According to the element content ratio shown in Table 1, 1.6mm diameter duplex stainless steel welding wire is made as the repair material for 2205 duplex stainless steel plates.

[0030] Table 1. Elemental content ratio of duplex stainless steel welding wire The selected repair equipment includes an additive manufacturing experimental platform consisting of an arc welding torch, a WF-007A multi-functional wire feeder, and a KUKA robot. The wire feeder adopts a pulse wire feeding mode. A gas metal arc welding (GMAW) additive manufacturing system was selected, as the welding power source exhibits good stability and controllability. The welding equipment parameters were adjusted, including welding current, voltage, welding speed, and gas flow rate. The first layer was welded with a current of 128A, a voltage of 19V, an overlap rate of 40%, a welding speed of 10m / min, and a wire feed speed of 4.5m / min. Subsequent layers were welded with the same parameters: current of 128A, voltage of 19V, overlap rate of 40%, welding speed of 10m / min, and wire feed speed of 4.5m / min. Argon was used as the shielding gas, and the flow rate was set to 15L / min. A single pass was then claddinged using the above parameters. Figure 2 As shown, Figure 2 a represents a single pass of arc additive cladding, with the single pass width and height measured to be 6mm and 3mm respectively.

[0031] The fourth step is to calculate the number of cycles using formulas combined with repair process parameters. .like Figure 1 The image shown is a 3D cloud map and path planning diagram of the repaired board. Figure 1 It can be seen that, Figure 1 The blue area represents the stainless steel sheet being repaired, and the yellow area represents the area that needs to be repaired. The area to be repaired has a regular shape, and the total repair length is 110mm. According to the formula, the number of forming cycles for each layer is 29. Figure 1 b is a schematic diagram of the repair path, which involves unidirectional cyclic repair. Figure 1 The numbers 1, 2, 3, and 4 marked in b indicate the location of the repair area. Unidirectional cyclic repair means that starting from the edge of repair area 13, repair is carried out in a unidirectional manner from 1 to 3, along the direction from 1 to 2, until the edge 24 is reached.

[0032] Fifth, fix the pretreated 2205 duplex stainless steel sheet on the workbench and adjust the welding torch position to align it with the defect area. Start the welding equipment and establish an initial molten pool at the defect area. By controlling the welding parameters, maintain the shape and size of the molten pool.

[0033] Step 6: Additive repair is performed using a layered stacking method, with the repair path employing... Figure 1 Repair according to the prescribed repair path. After repairing one layer, readjust the welding torch. Figure 1 The location shown (position 1) should be repaired according to the prescribed repair path. After each layer is deposited, the weld slag formed on the surface should be brushed off with a wire brush to avoid affecting the deposit effect between layers. An infrared thermometer should be used to measure the temperature of the repaired area. When the interlayer temperature exceeds 150℃, depositing should be stopped, and the repaired area should be allowed to cool naturally to 100-150℃ before proceeding with the next layer. By controlling the interlayer temperature, the heat-affected zone is reduced.

[0034] Step 7: During the additive repair process, monitor the welding current, voltage, and shielding gas flow rate in real time to ensure parameter stability. For example... Figure 2 As shown, Figure 2 b is a macroscopic morphological image of the repaired 2205 duplex stainless steel sheet.

[0035] Step 8: Cut 9mm×9mm×9mm samples from the repaired area. After heat treatment, perform hardness testing and electrochemical experiments to test the uniformity of microstructure, mechanical properties, and corrosion resistance before and after heat treatment, and compare them with the substrate. Divide the cut samples into three groups. One group was not heat treated and was designated as Sample 1. The other two groups were placed in a furnace at 1050℃ and held for 13.5 min (Sample 2) and 27 min (Sample 3), respectively, before being removed and water-quenched. Two pieces were taken from each group and divided into two subgroups. One subgroup had its coating surface polished and underwent Rockwell hardness testing; the other subgroup had its cross-section polished and then subjected to electrochemical corrosion in a 3.5% NaCl solution.

[0036] Hardness tests were performed on the coating surface and then compared with the substrate. The results are shown in Table 2.

[0037] Table 2 Hardness Test Results As can be seen from Table 2, under this repair method, the Rockwell hardness of the repair layer without heat treatment is significantly higher than that of the substrate surface, while the hardness of the repair layer after heat treatment is slightly lower than that of the substrate.

[0038] Figure 3 The image shows the microstructure of the interface between the repaired arc additive repair layer and the 2205 duplex stainless steel substrate. The upper half of the image represents the arc additive repair layer, and the lower half represents the substrate. The two layers have a good bond, and no cracks were found in the microstructure.

[0039] Figure 4 , Figure 5 and Figure 6Microscopic morphology images of the arc additive repair layer of Sample 1 (without heat treatment), Sample 2 (heat-treated for 13.5 min), and Sample 3 (heat-treated for 27 min) are presented. Sample 1, without heat treatment, exhibits coarse grains and relatively straight grain boundaries with random grain orientation. After 13.5 min of heat treatment, the grains in Sample 2 begin to refine, and the grain boundaries become more complex, improving the strength and toughness of the repaired surface. In Sample 3, with the heat treatment time extended to 27 min, the grains are further refined, the microstructure becomes more uniform, and the grain boundaries become more complex, further improving the strength and toughness of the repair material. Compared to Sample 1, Samples 2 and 3 have a more uniform microstructure; heat treatment can eliminate residual stress generated during the repair process, improving their mechanical properties.

[0040] like Figure 4 , Figure 5 and Figure 6 As shown, the microstructure of the arc additive repair layer of samples 1, 2 and 3 is a uniform two-phase microstructure. However, the ratio of ferrite to austenite in samples 2 and 3 after heat treatment is close to 1:1, and there is no obvious grain coarsening or microstructure inhomogeneity.

[0041] Figure 7 The polarization curves of the electrochemical corrosion of the repaired coating surface and the substrate are shown in the figure. It can be observed that the polarization curves of the repaired samples 1, 2, and 3, and the substrate, exhibit roughly the same trend, all showing a stable anodic passivation range in the 3.5% NaCl electrolyte. The self-corrosion potential (Ei) of the coating surface and the substrate was calculated using the Tafel extrapolation method. corr ) and self-corrosion current density (I corr The results are shown in Table 3. Table 3 shows that the self-corrosion current density of the repaired surface increases with increasing heat treatment time, while the self-corrosion potential decreases with increasing heat treatment time. Furthermore, the repaired surface of sample one has the closest positive self-corrosion potential, with a value of -0.262083903 V, indicating the lowest tendency to corrode. The repaired surface of sample one also has the smallest self-corrosion current density, with a value of 1.221435 V. 10 -7 The self-corrosion current density is lower than that of the substrate, indicating that the corrosion rate of the repaired surface in this embodiment is the lowest, and the corrosion resistance is better at this time.

[0042] Table 3 Self-corrosion potential and self-corrosion current density of coating surface and substrate The results of heat treatment and electrochemical experiments show that the arc additive repair layer has similar microstructure, mechanical properties and corrosion resistance to the 2205 duplex stainless steel substrate, which meets the requirements of practical engineering applications.

[0043] The repaired area is ground and polished to achieve the required surface roughness.

[0044] The repair results show that the arc-assisted additive manufacturing method for repairing 2205 duplex stainless steel sheets resulted in good bonding between the repair layer and the substrate, with no cracks appearing. The repair layer exhibited improved hardness and corrosion resistance compared to the substrate. Furthermore, the heat-treated repair layer achieved hardness and corrosion resistance even closer to that of the substrate. This ensures the overall stability of the sheet material's performance and reduces the risk of secondary damage.

[0045] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for arc additive repair of 2205 duplex stainless steel sheet, characterized in that: Includes the following steps: S1. Pre-treat the area to be repaired in the 2205 duplex stainless steel sheet substrate; S2. Using 3D modeling software, an original data model is constructed based on the length, width, and height of the 2205 duplex stainless steel sheet substrate. A reference point is specified near the area to be repaired of the 2205 duplex stainless steel sheet substrate. Then, a 3D scanner is used to scan from multiple directions from the reference point to obtain point cloud data, extract feature points to establish a wear model, collect 3D cloud maps of the 2205 duplex stainless steel sheet substrate and the area to be repaired, slice the area to be repaired into layers, and calculate the length, width, and height of the area to be repaired. S3. Set the process parameters for arc additive repair: wire feed speed 4-4.5m / min, welding speed 5-20m / min, overlap rate 30%-50%, welding voltage 15-20V, welding current 125-130A, shielding gas argon flow rate 10-15L / min; then use the above parameters to clad a single pass on the 2205 duplex stainless steel substrate, measure the width and height of the single pass, and calculate the repair path in combination with the repair process parameters; S4. Using an electric arc as a heat source, additive repair is carried out by depositing single-layer weld beads layer by layer to complete the repair work on the area to be repaired of the 2205 duplex stainless steel plate substrate. S5. After the repair is completed, heat treatment, grinding and post-treatment and testing are carried out on the repaired area in sequence.

2. The method for arc additive repair of 2205 duplex stainless steel sheet according to claim 1, characterized in that: The pretreatment method described in S1 is as follows: by cleaning and grinding, surface contaminants on the area to be repaired of the 2205 duplex stainless steel sheet substrate are removed to enhance bonding strength, optimize forming quality, reduce welding defects, and adapt to complex repair needs.

3. The method for arc additive repair of 2205 duplex stainless steel sheet according to claim 1, characterized in that: The calculation method for the repair path described in S3 is as follows: The repair method adopts a unidirectional cyclic repair. The total repair length is in mm, and the width of a single repair is 5-12 mm.

4. The method for arc additive repair of 2205 duplex stainless steel sheet according to claim 1, characterized in that: The repair material used in the arc additive repair is duplex stainless steel welding wire with a diameter of 1.2-3.2 mm. The chemical composition of the duplex stainless steel welding wire is as follows: C≤0.03%, Mn≤2.00%, P≤0.03%, S≤0.03%, Si≤0.90%, Ni: 7.50-9.50%, Cr: 21.50-23.50%, Mo: 2.50-3.50%, N: 0.08-0.20%, and Fe as the balance.

5. The method for arc additive repair of 2205 duplex stainless steel sheet according to claim 1, characterized in that: The temperature of the electric arc used as a heat source in S4 is 1500℃. During the additive repair process, the welding current, welding voltage, and shielding gas flow rate parameters are monitored in real time to ensure the stability of the parameters. If any repair abnormality is found, the equipment parameters are adjusted in time or the additive repair process is stopped, and the equipment and process are checked.

6. The method for arc additive repair of 2205 duplex stainless steel sheet according to claim 1, characterized in that: The heat treatment, grinding and testing methods described in S5 are as follows: Samples are taken from the repair area and heat-treated to eliminate residual stress, adjust the two-phase ratio and improve the microstructure; then, flaw detection is performed, and its corrosion resistance is tested by electrochemical experiments; subsequently, the repair area is ground and polished to ensure that the surface roughness Ra≤3.2μm, so that its surface roughness meets the requirements for use.

7. The method for arc additive repair of 2205 duplex stainless steel sheet according to claim 6, characterized in that: The heat treatment method is as follows: Samples are taken from the surface of the repair area and divided into three groups. Two of the groups are placed in a furnace at 1050℃ and kept at that temperature for 13.5 min and 27 min respectively. They are then taken out and cooled by water quenching, and compared with the third group that has not undergone heat treatment.

8. A method for arc additive repair of 2205 duplex stainless steel sheet as described in any one of claims 1-7, applied to the repair of large-size 2205 duplex stainless steel sheet, characterized in that: The large dimensions are defined as follows: the length of the 2205 duplex stainless steel sheet substrate to be repaired is ≥500mm, the width is ≥100mm, and the height is ≥50mm.

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