Optimization method for welding equipment and process of steel annealing and pickling production line

Abstract

The invention discloses an optimization method for welding equipment and a process of a steel annealing and pickling production line. The optimization method comprises the following steps: S1, adopting pure Ar gas as welding shielding gas; s2, replacing a large-diameter protective nozzle; s3, a gas screen is additionally arranged at a protective gas outlet of the welding gun, and a protective net is additionally arranged in the gas screen; s4, the push-pull type wire feeding mechanism is replaced; s5, process parameters of welding equipment are adjusted; and S6, the steel is connected with the titanium material, so that the special connecting band is formed. By improving the welding equipment and optimizing the welding process, the problems of titanium material MIG welding air suction brittle failure, unsmooth wire feeding, parameter mismatching, dissimilar material connection failure and the like are solved, it is ensured that the welding seam quality meets the subsequent annealing and pickling procedure requirement, the welding efficiency adapts to the continuous operation rhythm of a production line, and it is ensured that titanium materials can be produced in batches.

Description

Technical Field

[0001] This invention belongs to the field of titanium welding technology, specifically relating to an optimization method for welding equipment and processes in a steel annealing and pickling production line. Background Technology

[0002] MIG welding is a welding method in which an inert gas is used to coat the welding parts, which stabilizes the electric arc and prevents changes in weld quality. The heat of the electric arc melts the metal of the welding parts, and then a welding rod is fed in to connect the weld. It is also commonly known as semi-automatic welding, coated gas arc welding, or carbon dioxide arc welding.

[0003] Currently, due to the good economic benefits and wide range of applications of titanium materials, there is a need to expand production on existing stainless steel or carbon steel annealing and pickling production lines. However, the MIG welding in the related steel annealing and pickling production lines has the following defects: Titanium is extremely sensitive to elements such as hydrogen, oxygen, and nitrogen in high-temperature environments. Existing MIG welding equipment has a narrow protection range and serious gas absorption in the weld, which leads to brittle fracture at 20° cold bending and cannot pass the subsequent annealing and pickling process. Titanium welding wire has low strength. The existing wire feeding mechanism of MIG welding equipment does not feed wire smoothly in continuous MIG welding operations, resulting in poor arc stability, frequent arc breakage and burnout, and affecting the continuous operation of the production line. The welding parameters for MIG welding of titanium and steel differ significantly, and existing welding process parameters cannot be directly applied. Titanium and steel cannot be directly welded, and there is a lack of effective connection methods suitable for continuous operation of steel annealing and pickling production lines.

[0004] Therefore, the aforementioned defects make it difficult to establish a successful MIG welding process for titanium materials on this type of production line, which restricts production efficiency and product quality, and urgently requires a targeted optimization solution. Summary of the Invention

[0005] To address all or part of the aforementioned problems, the present invention aims to provide an optimization method for welding equipment and processes in a steel annealing and pickling production line. By improving welding equipment and optimizing welding processes, the invention aims to improve issues such as brittle fracture due to air intake during MIG welding of titanium materials, poor wire feeding, parameter mismatch, and failure of connections between dissimilar materials. This ensures that the weld quality meets the requirements of subsequent annealing and pickling processes, and that the welding efficiency is adapted to the continuous operation rhythm of the production line, thereby ensuring that titanium materials can be mass-produced.

[0006] This invention provides an optimization method for welding equipment and processes in a steel annealing and pickling production line, comprising the following steps: S1 uses pure Ar gas as the welding shielding gas; S2, Replace with a larger diameter protective nozzle; S3, Install a gas screen at the shielding gas outlet of the welding torch and add a protective net inside it; S4, Replace the push-pull type wire feeding mechanism; S5, adjust the process parameters of the welding equipment; S6 connects steel and titanium to form a special connecting strip.

[0007] Alternatively, in S2: The diameter of the protective nozzle is controlled to be 32-34mm, and an air screen hole is opened on the protective nozzle. The protective nozzle and the welding equipment are connected in a detachable manner.

[0008] Alternatively, in S2: The number of control air screen holes is multiple and they are arranged at equal intervals along the circumference of the protective nozzle. The diameter of the control air screen holes is 1.0-1.4mm and the hole spacing is 1.5-2.5mm.

[0009] Alternatively, in S3: The air sieve is made of ceramic, and the thickness of the air sieve is controlled to be 1.5-2.5mm and the inner diameter is 8-12mm. The protective netting uses fine copper mesh, and the mesh size is controlled to be 80-120 mesh.

[0010] Alternatively, in S4: Control the diameter of the graphite wire feeding tube to 1.5-2.5mm, control the orifice diameter of the conductive tip to 1.2-1.6mm, fix a stainless steel nut at the upper end of the graphite wire feeding tube, and extend the graphite wire feeding tube 8-12mm beyond the nut.

[0011] Alternatively, in S5: The welding equipment is controlled with a current of 300-350A, a voltage of 28-32V, a wire feed speed of 20-24m / min, a welding speed of 0.6-0.9m / min, a shielding gas flow rate of 16-23L / min, a weld gap of 2-3mm, and a weld extension of 5-7mm.

[0012] Alternatively, in S6: One side of the control connecting plate is a stainless steel plate and the other side is a titanium plate. Multiple rounded holes are equally spaced on the titanium plate, and multiple connecting strips are cut on one side of the stainless steel plate. The multiple connecting strips are inserted into the corresponding rounded holes, and then the multiple connecting strips are folded and welded to the stainless steel plate using TIG welding.

[0013] Alternatively, in S6: The diameter of the rounded corner holes is controlled to be 90-110mm, and the hole spacing is 55-65mm.

[0014] Alternatively, in S6: The width of the control connecting strip is 15-25mm and the thickness is 3-5mm.

[0015] Alternatively, in S6: The thickness difference between the stainless steel plate and the titanium plate of the connecting strip is controlled to be ≤1mm, and the thickness difference between the stainless steel plate of the connecting strip and the base material is controlled to be ≤1mm.

[0016] As can be seen from the above technical solution, the optimized welding equipment and process of the steel annealing and pickling production line provided by the present invention has the following advantages: The optimization method of this welding equipment and process can improve problems such as brittle fracture due to air intake, poor wire feeding, parameter mismatch, and failure of dissimilar material connection in titanium MIG welding, ensure that the weld quality meets the requirements of subsequent annealing and pickling processes, and adapt the welding efficiency to the continuous operation rhythm of the production line, ensuring that titanium materials can be mass-produced.

[0017] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0018] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0019] Figure 1 This is a flowchart of an embodiment of the present invention; Figure 2 This is a schematic diagram of the protective air nozzle in an embodiment of the present invention; Figure 3 This is a schematic diagram of the protective air nozzle in an embodiment of the present invention; Figure 4 This is a schematic diagram of the protective air nozzle in an embodiment of the present invention; Figure 5 This is a schematic diagram of the wire feeding mechanism in an embodiment of the present invention; Figure 6 This is a schematic diagram of the connecting strip structure in an embodiment of the present invention; Figure 7 This is a schematic diagram of the connecting strip in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be arbitrarily combined with each other.

[0021] like Figures 1-7The illustration shows an embodiment of the present invention, which discloses an optimization method for welding equipment and processes in a steel annealing and pickling production line, comprising the following steps: S1 uses pure Ar gas as the welding shielding gas; S2, Replace with a larger diameter protective nozzle; S3, Install a gas screen at the shielding gas outlet of the welding torch and add a protective net inside it; S4, Replace the push-pull type wire feeding mechanism; S5, adjust the process parameters of the welding equipment; S6 connects steel and titanium to form a special connecting strip.

[0022] In S1: Pure Ar gas is used as the shielding gas for MIG welding to prevent titanium from absorbing oxygen and oxidizing, ensuring that the weld can withstand subsequent annealing and pickling corrosion.

[0023] In S2: like Figure 2 , Figure 3 , Figure 4 As shown, the diameter of the protective nozzle is controlled to be 32-34 mm to improve the protective effect. In this embodiment, the diameter of the protective nozzle is preferably 33 mm. Multiple air screen holes are opened on the protective nozzle to ensure that the protective gas is in a "laminar flow state". The multiple air screen holes are arranged at equal intervals along the circumference of the protective nozzle to avoid air being drawn in during the MIG welding process, which would cause the weld to suck in air.

[0024] The diameter of the air screen holes is controlled to be 1.0-1.4 mm, and the hole spacing is 1.5-2.5 mm. In this embodiment, the diameter of the air screen holes is preferably 1.2 mm, and the hole spacing is preferably 2 mm. Meanwhile, the protective nozzle and the welding equipment are detachably connected. In this embodiment, the protective nozzle and the welding equipment are preferably connected by a thread, so as to facilitate quick replacement of the protective nozzle on the production line.

[0025] In S3: like Figure 2 , Figure 3 , Figure 4 As shown, a ceramic gas screen is used, and a fine copper mesh is used for the protective net to solve the weld seam undercut defect caused by uneven protective gas from large-diameter nozzles, balance the protective effect and gas flow, and avoid affecting the continuous operation of the production line. Simultaneously, the thickness of the gas screen is controlled to be 1.5-2.5mm, the inner diameter to be 8-12mm, and the mesh size of the protective net to be 80-120 mesh. In this embodiment, the preferred thickness of the gas screen is 2mm, the preferred inner diameter is 10mm, and the preferred mesh size of the protective net is 100 mesh.

[0026] In S4: The wire feeding mechanism of the welding equipment is upgraded to a push-pull type, solving the wire accumulation problem of the wire feeding wheel in continuous MIG welding operations and ensuring uninterrupted operation of the production line. Simultaneously, a graphite wire feeding tube with lower damping is used instead of a stainless steel spring tube, and the diameter of the graphite wire feeding tube is controlled at 1.5-2.5 mm, thereby effectively reducing the resistance of the titanium wire in continuous MIG welding feeding. In this embodiment, the diameter of the graphite wire feeding tube is preferably 2 mm.

[0027] like Figure 5 As shown, the orifice diameter of the conductive tip is controlled to be 1.2-1.6 mm to improve conductivity stability and wire feeding smoothness, balance the conductivity of MIG welding with wire feeding stability, and avoid a sharp increase in wire feeding resistance caused by changes in wire curvature. In this embodiment, the orifice diameter of the conductive tip is preferably controlled to be 1.4 mm.

[0028] A stainless steel nut is fixed to the upper end of the graphite wire feed tube, with the graphite wire feed tube extending 8-12mm beyond the nut. This prevents the graphite wire feed tube from being carried into the vicinity of the contact tip, where it melts and sticks due to high temperature, thus reducing production line downtime for maintenance. If the graphite wire feed tube is directly installed in the pipeline, it will be carried into the vicinity of the contact tip as the welding wire is fed in. During welding, it will melt at high temperature and stick to the welding wire, completely blocking the contact tip after cooling and solidification. Fixing it with a stainless steel nut facilitates the fixation of the graphite wire feed tube and minimizes the risk of bending and wire bridging of the titanium wire. In this embodiment, an M8 stainless steel nut is preferred, and the graphite wire feed tube extends 10mm beyond the nut.

[0029] In S5: Based on the differences in resistance and melting point between titanium and steel, and considering the continuous operation requirements of MIG welding in the annealing and pickling production line, we adopted adaptation parameters that are about 20% larger than those for 430 stainless steel MIG welding. The specific control parameters are: current 300-350A, voltage 28-32V, wire feed speed 20-24m / min, welding speed 0.6-0.9m / min, shielding gas flow rate 16-23L / min, weld gap 2-3mm, and weld extension 5-7mm, to ensure good weld fusion and adaptability to subsequent annealing and pickling processes.

[0030] In S6: like Figure 6 , Figure 7 As shown, one side of the control connecting plate is a stainless steel plate and the other side is a titanium plate. Multiple rounded holes are equally spaced on the titanium plate, and multiple connecting strips are cut on one side of the stainless steel plate. The multiple connecting strips are inserted into the corresponding rounded holes, and then the multiple connecting strips are folded and welded to the stainless steel plate using TIG welding.

[0031] The diameter of the rounded corner holes is controlled to be 90-110mm, the hole spacing to be 55-60mm, and the width of the connecting strip to be 15-25mm and the thickness to be 3-5mm. In this embodiment, the diameter of the rounded corner holes is preferably 100mm, the hole spacing is preferably 60mm, the width of the connecting strip is preferably 20mm, and the thickness is preferably 4mm. The thickness difference between the stainless steel plate and the titanium plate of the connecting strip is controlled to be ≤1mm, and the thickness difference between the stainless steel plate and the base material of the connecting strip is controlled to be ≤1mm. This avoids the appearance of a rolling transition section on the titanium plate side, ensures stable tension during line passing, and meets the continuous operation requirements of the annealing and pickling production line.

[0032] The optimized welding equipment and process method in this embodiment can improve problems such as brittle fracture due to air intake, poor wire feeding, parameter mismatch, and failure of dissimilar material connection in titanium MIG welding, ensuring that the weld quality meets the requirements of subsequent annealing and pickling processes, and that the welding efficiency is adapted to the continuous operation rhythm of the production line, ensuring that titanium materials can be mass-produced.

[0033] To more clearly illustrate the solution of this application, specific embodiments are listed below: Example 1 The optimized solution of this invention is used for MIG welding of 4mm thick TA2 titanium material in a stainless steel annealing and pickling production line: Pure Ar was used as the welding shielding gas, and the gas flow rate was controlled at 18 L / min. Select a 33mm diameter split-type protective nozzle, and use a ceramic air screen + 100-mesh copper protective mesh; It adopts a push-pull wire feeding mechanism, and is equipped with a graphite wire feeding tube with an inner diameter of 2mm and a conductive tip with an orifice diameter of 1.4mm; The MIG welding parameters are set as follows: current 320A, voltage 30V, wire feed speed 22m / min, welding speed 0.7m / min, weld gap 2.5mm, and weld extension 6mm. The connecting strip is formed by connecting titanium plates and 304 stainless steel.

[0034] Tests showed that the weld had a yield strength of 358 MPa, a tensile strength of 489 MPa, an elongation after fracture of 16%, and was intact when cold-bent at 180° (d=4a, d=10a), and successfully passed the subsequent annealing and pickling processes.

[0035] Example 2 The optimized solution of this invention is used for MIG welding of 5mm thick TA1 titanium material in a carbon steel annealing and pickling production line: Pure Ar was used as the welding shielding gas, and the gas flow rate was controlled at 20 L / min. Select a 33mm diameter split-type protective nozzle, and use a ceramic air screen + 100-mesh copper protective mesh; It adopts a push-pull wire feeding mechanism, and is equipped with a graphite wire feeding tube with an inner diameter of 2mm and a conductive tip with an orifice diameter of 1.4mm; The MIG welding parameters are set as follows: current 340A, voltage 31V, wire feed speed 23m / min, welding speed 0.8m / min, weld gap 2.5mm, and weld extension 6mm. The connecting strip is formed by connecting titanium plates and 304 stainless steel.

[0036] Tests showed that the weld had a yield strength of 336 MPa, a tensile strength of 472 MPa, and an elongation after fracture of 17%, with no brittle fracture. The connecting strip passed the tension test on the production line stably.

[0037] Example 3 The optimized solution of this invention is used for MIG welding of 6mm thick TA2 titanium material in a stainless steel annealing and pickling production line: Pure Ar was used as the welding shielding gas, and the gas flow rate was controlled at 22 L / min; Select a 33mm diameter split-type protective nozzle, and use a ceramic air screen + 100-mesh copper protective mesh; It adopts a push-pull wire feeding mechanism, and is equipped with a graphite wire feeding tube with an inner diameter of 2mm and a conductive tip with an orifice diameter of 1.4mm; The MIG welding parameters are set as follows: current 350A, voltage 32V, wire feed speed 24m / min, welding speed 0.9m / min, weld gap 2.5mm, and weld extension 6mm. The connecting strip is formed by connecting titanium plates and 304 stainless steel.

[0038] Tests showed that the weld had a tensile strength of 483 MPa and an elongation after fracture of 18%, meeting the requirements for continuous production. The annual production totaled 760 tons, and there were no production line shutdowns due to welding problems.

[0039] As shown above, the optimized welding equipment and process can be directly applied to MIG welding operations without significant modifications to existing production line equipment. Furthermore, the weld tensile strength is close to that of the base material, and there is no fracture after a 180° cold bend. The surface oxide layer does not affect subsequent processes such as annealing, pickling, descaling, and straightening, achieving a pass rate of over 99%. Moreover, the welding time for a single weld pass is controlled within 2-3 minutes, and the wire feed arc breakage rate is reduced to <1%, minimizing production line downtime losses.

[0040] Furthermore, the optimized welding equipment and process enabled the mass production of 2-6mm titanium materials via MIG welding on stainless steel / carbon steel annealing and pickling production lines, expanding the product range of the production line. Based on an annual output of 5400 tons and a profit of 500 yuan per ton, the optimized welding equipment and process generated approximately 2.7 million yuan in annual revenue. This provides crucial technical support for the mass production of titanium materials on this type of production line and has broad application value.

[0041] It should be noted that, unless otherwise stated, the technical or scientific terms used in this invention should have the ordinary meaning as understood by one of ordinary skill in the art.

[0042] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An optimization method for welding equipment and processes in a steel annealing and pickling production line, characterized in that, Includes the following steps: S1 uses pure Ar gas as the welding shielding gas; S2, Replace with a larger diameter protective nozzle; S3, Install a gas screen at the shielding gas outlet of the welding torch and add a protective net inside it; S4, Replace the push-pull type wire feeding mechanism; S5, adjust the process parameters of the welding equipment; S6 connects steel and titanium to form a special connecting strip.

2. The method for optimizing the welding equipment and process of the steel annealing and pickling production line according to claim 1, characterized in that, In S2: The diameter of the protective nozzle is controlled to be 32-34mm, and an air screen hole is opened on the protective nozzle. The protective nozzle and the welding equipment are connected in a detachable manner.

3. The method for optimizing the welding equipment and process of the steel annealing and pickling production line according to claim 2, characterized in that, In S2: The number of control air screen holes is multiple and they are arranged at equal intervals along the circumference of the protective nozzle. The diameter of the control air screen holes is 1.0-1.4mm and the hole spacing is 1.5-2.5mm.

4. The method for optimizing the welding equipment and process of the steel annealing and pickling production line according to claim 1, characterized in that, In S3: The air sieve is made of ceramic, and the thickness of the air sieve is controlled to be 1.5-2.5mm and the inner diameter is 8-12mm. The protective netting uses fine copper mesh, and the mesh size is controlled to be 80-120 mesh.

5. The method for optimizing the welding equipment and process of the steel annealing and pickling production line according to claim 1, characterized in that, In S4: Control the diameter of the graphite wire feeding tube to 1.5-2.5mm, control the orifice diameter of the conductive tip to 1.2-1.6mm, fix a stainless steel nut at the upper end of the graphite wire feeding tube, and extend the graphite wire feeding tube 8-12mm beyond the nut.

6. The method for optimizing the welding equipment and process of the steel annealing and pickling production line according to claim 1, characterized in that, In S5: The welding equipment is controlled with a current of 300-350A, a voltage of 28-32V, a wire feed speed of 20-24m / min, a welding speed of 0.6-0.9m / min, a shielding gas flow rate of 16-23L / min, a weld gap of 2-3mm, and a weld extension of 5-7mm.

7. The method for optimizing the welding equipment and process of the steel annealing and pickling production line according to claim 1, characterized in that, In S6: One side of the control connecting plate is a stainless steel plate and the other side is a titanium plate. Multiple rounded holes are equally spaced on the titanium plate, and multiple connecting strips are cut on one side of the stainless steel plate. The multiple connecting strips are inserted into the corresponding rounded holes, and then the multiple connecting strips are folded and welded to the stainless steel plate using TIG welding.

8. The method for optimizing the welding equipment and process of the steel annealing and pickling production line according to claim 7, characterized in that, In S6: The diameter of the rounded corner holes is controlled to be 90-110mm, and the hole spacing is 55-65mm.

9. The method for optimizing the welding equipment and process of the steel annealing and pickling production line according to claim 7, characterized in that, In S6: The width of the control connecting strip is 15-25mm and the thickness is 3-5mm.

10. The method for optimizing the welding equipment and process of the steel annealing and pickling production line according to claim 7, characterized in that, In S6: The thickness difference between the stainless steel plate and the titanium plate of the connecting strip is controlled to be ≤1mm, and the thickness difference between the stainless steel plate of the connecting strip and the base material is controlled to be ≤1mm.

Images