Narrow-gap hot wire TIG-welding rod composite welding method for high-strength wear-resistant steel

Abstract

The invention relates to a narrow-gap hot wire TIG (Tungsten Inert Gas)-welding rod hybrid welding method for high-strength wear-resistant steel, which is characterized in that a U-shaped groove is designed, a truncated edge of 2-3mm is reserved at the bottom, a welding mode and a welding process of combining an advanced narrow-gap hot wire TIG (Tungsten Inert Gas) welding method with traditional manual shielded metal arc welding are adopted, and welding seam backing welding and filling welding adopt narrow-gap hot wire TIG welding; the method has the beneficial effects that efficient welding of the thick-specification wear-resistant steel and the quality and performance of a welding joint are guaranteed, meanwhile, the wear-resistant steel welding seam with multiple excellent performance such as toughness, corrosion resistance and friction and wear resistance of the welding seam is achieved, the welding workload is small, the welding seam effect is good, and the welding quality is high. And a welding technical support is provided for popularization and application of the high-strength wear-resistant steel.

Description

Technical Field

[0001] The present invention relates to the technical field of welding processes for thick-specification high-strength wear-resistant steel, and particularly to a narrow-gap hot-wire TIG-electrode composite welding method for high-strength wear-resistant steel. Background Art

[0002] With the development of China's national economy and society, the technical level of China's industrial equipment has made great progress. During the construction of a large number of infrastructure such as real estate, bridges, tunnels, and roads, the use frequency of engineering machinery and equipment is very high, and the wear and tear of the equipment is very serious, causing great losses to the national economy. Therefore, the use of wear-resistant steel in engineering machinery has gradually increased.

[0003] However, there are also some problems in the manufacturing process of high-strength wear-resistant steel for engineering machinery and equipment: (1) The carbon equivalent of high-strength wear-resistant steel is generally higher than that of ordinary low-alloy high-strength steel, and its weldability is poor. Delayed cracks are likely to occur after welding, affecting the usability of high-strength wear-resistant steel equipment; (2) Since low-strength matching welding materials are generally used for high-strength wear-resistant steel, the wear resistance of the weld is lower than that of the base metal. During use, the wear degree of the weld is relatively large, and the weld is easily worn and damaged, affecting the service life of high-strength wear-resistant steel equipment; (3) The thickness of thick-specification wear-resistant steel plates is relatively large, resulting in a large amount of welding work, poor weld quality, and poor welding effect of the weld, affecting the use of high-strength wear-resistant steel equipment. At this time, a suitable welding process method plays a crucial role in the quality and performance of the welded joint. Single welding methods, such as shielded metal arc welding, gas shielded welding, and submerged arc welding, all have their own advantages and obvious disadvantages. After adopting a new composite welding method, the corresponding welding process and parameters need to be changed accordingly to ensure the mechanical properties of the welded joint.

[0004] Patent CN114309899B, "Welding Method for Low-Alloy Wear-Resistant Steel and Its Welded Joint", discloses a welding method for low-alloy wear-resistant steel, which includes the following steps: First, process the welding groove for the wear-resistant steel to be welded, and preheat the welding groove and the wear-resistant steel on both sides of the welding groove; then use the double-wire submerged arc welding method for root pass welding and filling welding; finally, use the method of cold wire filling double-wire submerged arc welding for capping welding. This patent also discloses the welded joint obtained by the above welding method. In the welding method of this patent, double-wire submerged arc welding is used for root pass and filling welding, and cold wire filling double-wire submerged arc welding is used for capping welding. On the premise of ensuring the comprehensive mechanical properties of the weld, the wear resistance is improved, and the welding efficiency is increased by 2-3 times compared with the existing mature welding technology, and the wear amount of the weld and the base metal under the same working conditions is basically the same, extending the service life. However, the groove used in this method is X-shaped or V-shaped, which is not suitable for welding thick-specification steel plates, and defects such as porosity, incomplete penetration, lack of fusion, or pits are likely to occur. Moreover, the welding operation amount of this patent is huge, the manual workload is huge, the welding quality cannot be guaranteed, the weld effect is poor, affecting the usability of high-strength wear-resistant steel and its applicable range.

[0005] Patent CN110238528B, "A Laser-Hot Wire TIG Hybrid Welding Method with Normal Wire Feeding", the invention relates to a laser-hot wire TIG hybrid welding method with normal wire feeding. This method includes: designing a welding groove at the welding position on the thick plate to be welded, and using high-power laser deep penetration welding to achieve root pass welding of the groove root face; using a method of combining a laser beam, a non-consumable electrode, and a continuously heated welding wire to perform layer-by-layer filling welding on the groove of the thick plate to be welded. During the welding process, the height position of the hybrid welding torch to the molten pool should be adjusted according to the single-layer filling thickness. Among them, the welding wire is inductively heated by a hot wire heating device. In the welding feeding direction, the laser beam is arranged in front of the welding wire, the non-consumable electrode is arranged behind the welding wire, and is placed in an inert gas protection cover; using the above hybrid welding method to perform capping welding on the groove weld of the thick plate to be welded to complete the hybrid welding. However, laser hybrid hot wire TIG hybrid welding cannot guarantee the wear resistance of the weld, and it is easy to cause serious wear and damage of the weld, affecting the use function of the equipment, reducing the use effect, and shortening the service life.

[0006] Patent CN115635253A, "Welded-clad composite weld for wear-resistant steel and welding method thereof", discloses a welded-clad composite weld for wear-resistant steel and its welding method, which includes an inner low-alloy steel filling layer and an outer WC particle-reinforced nickel-based alloy cover layer and / or backing layer; the welding material of the filling layer is obtained by gas shielded welding with a low-alloy steel wire, the cover layer is obtained by laser cladding technology using the residual heat of fusion welding, and the backing layer is obtained by melting using the residual heat of fusion welding. The weld provided by this patent uses a composite weld of low-alloy steel and WC particle-reinforced nickel-based alloy. The inner low-alloy steel filling layer has excellent mechanical properties, and the outer WC particle-reinforced nickel-based alloy cover layer / backing layer has good wear resistance, enabling the welded joint to have both good mechanical properties and wear resistance. However, this method has poor welding effect, bad welding quality, and obvious defects such as welding pits for thick-specification high-strength wear-resistant steel, the weld strength is lower than that of the high-strength wear-resistant steel itself, affecting the use of the high-strength wear-resistant steel, and the corrosion resistance and wear resistance are not good, restricting the application range of the high-strength wear-resistant steel. Summary of the Invention

[0007] In order to overcome the deficiencies of the prior art, the present invention provides a narrow-gap hot wire TIG-electrode composite welding method for high-strength wear-resistant steel. A U-shaped groove is designed with a root face of 2-3 mm left at the bottom. Through the welding method and welding process that combine the advanced narrow-gap hot wire TIG welding method with traditional manual shielded metal arc welding, the root pass welding and filling welding of the weld use narrow-gap hot wire TIG welding, and the cover pass welding uses manual shielded metal arc welding, which not only ensures the high-efficiency welding of thick-specification wear-resistant steel and the quality and performance of the welded joint, but also has a wear-resistant steel weld with various excellent properties such as the toughness, corrosion resistance, and friction and wear resistance of the weld, with less welding work and good weld effect, providing welding technical support for the popularization and application of high-strength wear-resistant steel.

[0008] To achieve the above object, the present invention is implemented by the following technical solutions:

[0009] A narrow-gap hot wire TIG-electrode composite welding method for high-strength wear-resistant steel, which adopts a composite welding method of superimposing narrow-gap hot wire TIG welding and manual shielded metal arc welding. The narrow-gap hot wire TIG-electrode composite welding method for high-strength wear-resistant steel includes the following contents:

[0010] S1. Welding groove processing: Design the U-shaped groove form according to the welding characteristics of narrow-gap hot wire TIG welding and the shape of the welding torch, and leave a root face of 2-3 mm at the bottom;

[0011] S2. The groove is removed by mechanical processing method. Before welding, use an angle grinder to remove the oxides and impurities in the area to be welded of the base metal steel plate, and wipe it with industrial alcohol until the interface shows metallic luster;

[0012] S3. After the groove of the high-strength wear-resistant steel plate to be welded is opened, it is assembled and placed, and the relative gap of the root face at the bottom is 2 - 3 mm;

[0013] S4. The area to be welded is preheated before welding, and the preheating temperature is 100 - 120 °C;

[0014] S5. The backing welding and filling welding are carried out by using the welding method of narrow-gap hot-wire TIG welding, and inert gas flow protection is used during the welding process;

[0015] S6. When using narrow-gap hot-wire TIG welding for filling welding, the welding current is increased by 20 - 60 A, and the filling welding ends at a position 7 - 8 mm away from the top surface of the groove;

[0016] S7. The cover welding from above the TIG filling welding bead to the top surface of the groove is carried out by using the welding method of manual shielded metal arc welding;

[0017] S8. After the composite welding of narrow-gap hot-wire TIG welding and manual shielded metal arc welding is completed, the welding joint is covered with heat-insulating cotton to reduce the cooling rate of the welding joint.

[0018] Furthermore, in step S5, the welding consumables used for narrow-gap hot-wire TIG welding are JQ.TG50 carbon steel argon arc welding wires, the tensile strength Rm of the welding wire > 490 MPa, and the impact energy Kv2 at - 30 °C > 27 J.

[0019] Furthermore, in step S5, the welding current of the narrow-gap hot-wire TIG welding is 110 - 180 A, the welding voltage is 12 - 16 V, the welding speed is 100 - 150 mm / min, and the oscillation width is 2 mm.

[0020] Furthermore, in step S5, high-purity argon gas is used as the shielding gas for the inert gas. Before welding, the weld is purged with gas for 3 s to fill the bottom of the weld with argon, and then the narrow-gap hot-wire TIG backing welding operation is carried out.

[0021] Furthermore, in step S7, the cover welding includes cover corrosion-resistant layer welding and cover wear-resistant layer welding. The cover corrosion-resistant layer welding is above the TIG filling welding bead, and the cover wear-resistant layer welding is from above the cover corrosion-resistant layer to the top surface of the groove.

[0022] Furthermore, the cover corrosion-resistant layer welding is carried out by manual shielded metal arc welding, and the welding consumables used are A132 stainless steel electrodes, with a specification of small-size electrodes with a diameter of 3.2 mm, a welding current of 70 - 90 A, a welding voltage of 14 - 16 V, and a welding speed of 100 - 120 mm / min.

[0023] Further, the surfacing wear-resistant layer is welded by manual shielded metal arc welding. The welding consumables used are D167 low-hydrogen sodium-coated manganese-silicon electrodes, with a specification of small-sized electrodes with a diameter of 3.2 mm. The welding current is 85 - 100 A, the welding voltage is 16 - 20 V, and the welding speed is 100 - 120 mm / min.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1) For the root pass and filler pass of the weld, the narrow-gap hot-wire TIG welding has a small heat input per unit length of the welding line, fewer welding passes, and less welding work. It can greatly reduce the probability of welding cracks in the welded joints of thick-specification wear-resistant steel, ensuring the high-efficiency welding of thick-specification wear-resistant steel and the quality and performance of the welded joints.

[0026] 2) The small heat input of narrow-gap hot-wire TIG welding can also reduce the area of the heat-affected zone and the area where the hardness and wear resistance decrease. To a certain extent, it can avoid the decrease in the hardness of the welded joint and obtain high-strength wear-resistant steel welds with excellent toughness, corrosion resistance, and friction and wear resistance.

[0027] 3) Using narrow-gap hot-wire TIG welding can reduce the groove area and the welding work, and can reduce the time required for the welding process. Compared with the prior art, it can reduce the welding operation time by 30% - 50%, reduce the welding cost, and bring economic benefits to the production unit.

[0028] 4) Using shielded metal arc welding with stainless steel electrodes and wear-resistant surfacing electrodes for the weld cap can form a wear-resistant and corrosion-resistant layer with excellent hardness, wear resistance, and corrosion resistance on the weld surface, reducing the difference in wear resistance between the weld and the base metal, improving the corrosion resistance of the weld. Compared with the prior art, the corrosion resistance is increased by 50%, avoiding the occurrence of "pits" in the weld of high-strength wear-resistant steel under a large amount of wear and corrosion during use, improving the service performance of high-strength wear-resistant steel equipment, extending the service life, and providing welding technical support for the popularization and application of high-strength wear-resistant steel.

[0029] 5) Using shielded metal arc welding for the cap welding has simple equipment, is easy to operate and carry, and can be quickly repaired and welded after the weld surface is damaged, reducing the impact on on-site production and lowering the enterprise cost.

[0030] 6) By testing the mechanical properties of the composite welded joint through tensile and impact tests, the tensile strength Rm of the weld is > 490 MPa, and the impact energy Kv2 at -30 °C is > 27 J; compared with the prior art, the corrosion resistance is increased by 50%, and the friction and wear resistance is increased by 100%. Its friction and wear resistance is higher than that of ordinary welding consumables, and the hardness is greater than 700 HV, comprehensively improving the welding performance of high-strength wear-resistant steel, improving the welding quality, increasing the use value of high-strength wear-resistant steel, expanding the scope of use, and increasing the economic value. Brief Description of the Drawings

[0031] Figure 1 It is a schematic diagram of the welding process described in the present invention.

[0032] Figure 2 It is a schematic diagram of the groove form described in the present invention.

[0033] In the figure: 1. Steel plate to be welded; 2. Groove; 3. Weld seam; 4. Root pass welding; 5. Filler pass welding; 6. Surfacing welding; 7. Surfacing corrosion-resistant layer welding; 8. Surfacing wear-resistant layer welding. Detailed Embodiments

[0034] The following further describes the detailed embodiments of the present invention with reference to the drawings:

[0035] Embodiment 1:

[0036] This embodiment is applied to the welding of NM500 high-strength wear-resistant steel with a plate thickness of 45 mm. The specific implementation process is as follows:

[0037] As Figure 1 - Figure 2 shown, the steel plate 1 to be welded is processed into a narrow-gap U-shaped groove 2 by mechanical processing method. Two steel plates 1 to be welded are assembled and processed. The side edges of each steel plate 1 on the welding side are processed into a single-sided semi-U-shaped groove 2 with a root face of 2 mm. The two sides of the welding side of the two steel plates to be welded form a U-shaped groove 2. Before welding, the groove 2 and the areas on both sides of the weld seam 3 with a width of 20 mm are cleaned and polished with a grinding wheel until they are bright and free of obvious oil stains, rust and other impurities.

[0038] The steel plate 1 with the groove 2 opened is fixed on the workbench for welding. The welding torch is first inserted into the bottom of the weld seam 3 at the position to be welded. After spraying high-purity argon shielding gas for 3 s, root pass welding 4 is carried out with a welding current of 110 A. Root pass welding 4 is carried out in two layers, with 2 passes for each layer. After root pass welding 4, narrow-gap hot wire TIG welding filler pass welding 5 is carried out with a welding current of 170 A, a welding speed of 120 mm / min, and a swing width of 2 mm. Filler pass welding 5 is carried out in 14 layers, with 2 passes for each layer. Filler pass welding 5 ends at a position 8 mm away from the top surface of the groove 2. During the processes of root pass welding 4 and filler pass welding 5, the shielding gas flow rate is 15 L / min.

[0039] A132 manual electrode arc welding is used for surfacing welding 6 to prepare the weld surfacing corrosion-resistant layer welding 7 with a welding current of 90 A, a welding speed of 100 mm / min, an electrode diameter of 3.2 mm, and the number of layers of the surfacing corrosion-resistant layer welding 7 is 1 layer of weld with 2 passes.

[0040] D167 manual electrode arc welding is used for surfacing welding 6 to prepare the weld surfacing wear-resistant layer welding 8 with a welding current of 100 A, a welding speed of 100 mm / min, and an electrode diameter of 3.2 mm. The number of layers of the surfacing wear-resistant layer welding 8 is 2 layers of weld with 2 passes.

[0041] After the capping welding 6, use heat-insulating cotton to cover the surface of the weld 3 until it slowly cools down to room temperature, reduce the cooling rate of the welded joint, avoid the appearance of delayed cracks, and perform flaw detection on the weld 3 after 72 hours. The results show that there are no defects such as cracks and pores on the surface weld, and the welding quality is good.

[0042] The mechanical properties of the weld are tested through tensile and impact tests. The tensile strength Rm is 553 MPa, and the impact energy Kv2 at -30 °C is 94 J; compared with the existing technology, the corrosion resistance is increased by 50%, and the friction and wear resistance is increased by 100%. Its friction and wear resistance is higher than that of ordinary welding materials, and the hardness reaches 834 HV.

[0043] Example 2:

[0044] This example is applied to the welding of NM500 high-strength wear-resistant steel with a plate thickness of 55 mm. The specific implementation process is as follows:

[0045] As Figure 1 - Figure 2 shown, use mechanical processing methods to machine the narrow-gap U-groove 2 on the steel plate to be welded 1. Two steel plates to be welded 1 are assembled and processed. Unilateral semi-U-shaped grooves 2 are machined on the side edges of each steel plate to be welded 1 on the welding side. The bottom root face is 2 mm. The two sides of the welding side of the two steel plates to be welded form a U-groove 2. Before welding, use a grinding wheel to clean and polish the groove 2 and the 20 mm area on both sides of the weld 3 until it is bright and free of obvious oil stains, rust and other impurities.

[0046] Fix the steel plate 1 with the groove 2 opened on the workbench for welding. First, insert the welding torch into the bottom of the weld 3 at the position to be welded, spray high-purity argon shielding gas for 3 s, and then perform backing welding 4 with a welding current of 110 A. The backing welding 4 is carried out in two layers, with 3 passes for each layer. After the backing welding 4, perform narrow-gap hot wire TIG welding filling welding 5, with a welding current of 160 A, a welding speed of 120 mm / min, and a swing width of 2 mm. The filling welding 5 is carried out in 16 layers, with 2 passes for each layer, and the filling welding 5 ends at a position 8 mm away from the top surface of the groove 2. The shielding gas flow rate is 15 L / min during the backing welding 4 and the filling welding 5.

[0047] Use A132 manual electrode arc welding to carry out capping welding 6 to prepare the corrosion-resistant layer welding 7 of the weld cap surface. The welding current is 80 A, the welding speed is 100 mm / min, the electrode diameter is 3.2 mm, and the number of layers of the corrosion-resistant layer welding 7 of the weld cap surface is 1 layer of weld, with 2 passes.

[0048] Use D167 manual electrode arc welding to carry out capping welding 6 to prepare the wear-resistant layer welding 8 of the weld cap surface. The welding current is 95 A, the welding speed is 100 mm / min, and the electrode diameter is 3.2 mm. The number of layers of the wear-resistant layer welding 8 of the weld cap surface is 2 layers of weld, with 2 passes.

[0049] After the capping welding 6, use heat-insulating cotton to cover the surface of the weld 3 until it slowly cools down to room temperature, reduce the cooling rate of the welded joint, avoid the appearance of delayed cracks, and perform flaw detection on the weld 3 after 72 hours. The results show that there are no defects such as cracks and pores on the surface weld, and the welding quality is good.

[0050] The mechanical properties of the weld are tested through tensile and impact tests. The tensile strength Rm is 572 MPa, and the impact energy Kv2 at -30 °C is 103 J; compared with the existing technology, the corrosion resistance is increased by 50%, and the friction and wear resistance is increased by 100%. Its friction and wear resistance is higher than that of ordinary welding materials, and the hardness reaches 789 HV.

[0051] Example 3:

[0052] This example is applied to the welding of 65 mm thick NM500 high-strength wear-resistant steel. The specific implementation process is as follows:

[0053] As Figure 1 - Figure 2 shown, use mechanical processing methods to process the narrow-gap U-groove 2 on the steel plate to be welded 1. Two steel plates to be welded 1 are assembled and processed. Unilateral semi-U-shaped grooves 2 are processed on the side edges of the welding side of each steel plate to be welded 1, with a root face of 2 mm at the bottom. The two sides of the welding side of the two steel plates to be welded form a U-groove 2. Before welding, use a grinding wheel to clean and polish the groove 2 and the 20 mm area on both sides of the weld 3 until it is bright and free of obvious oil stains, rust and other impurities.

[0054] Fix the steel plate to be welded 1 with the groove 2 opened on the workbench and prepare for welding. First, insert the welding torch into the bottom of the weld 3 at the position to be welded, spray high-purity argon shielding gas for 3 s, and then perform backing welding 4 with a welding current of 110 A. The backing welding 4 is carried out in two layers, with 2 passes for each layer. After the backing welding 4, narrow-gap hot-wire TIG welding filling 5 is carried out, with a welding current of 150 A, a welding speed of 120 mm / min, and a swing width of 2 mm. The filling welding 5 is carried out in 18 layers, with 2 passes for each layer, and the filling welding 5 ends at a position 8 mm away from the top surface of the groove 2. During the backing welding 4 and the filling welding 5, the shielding gas flow rate is 15 L / min.

[0055] Use A132 manual electrode arc welding to perform capping welding 6 to prepare the corrosion-resistant layer welding 7 of the weld cap, with a welding current of 70 A, a welding speed of 100 mm / min, an electrode diameter of 3.2 mm, and the number of layers of the corrosion-resistant layer welding 7 is 1 layer of weld, with 2 passes.

[0056] Use D167 manual electrode arc welding to perform capping welding 6 to prepare the wear-resistant layer welding 8 of the weld cap, with a welding current of 85 A, a welding speed of 100 mm / min, and an electrode diameter of 3.2 mm. The number of layers of the wear-resistant layer welding 8 is 2 layers of weld, with 2 passes.

[0057] After the cap surface welding 6, use heat-insulating cotton to cover the surface of the weld 3 until it slowly cools down to room temperature, reduce the cooling rate of the welded joint, avoid the appearance of delayed cracks, and perform flaw detection on the weld 3 after 72 hours. The results show that there are no defects such as cracks and pores on the surface weld, and the welding quality is good.

[0058] The mechanical properties of the weld are tested through tensile and impact tests. The tensile strength Rm is 546 MPa, and the impact energy Kv2 at -30 °C is 86 J; compared with the prior art, the corrosion resistance is increased by 50%, and the friction and wear resistance is increased by 100%. Its friction and wear resistance is higher than that of ordinary welding materials, and the hardness reaches 792 HV.

[0059] Process parameter table:

[0060]

[0061] Adopt different welding currents for different steel plate thicknesses. The greater the steel plate thickness, the greater the welding stress during welding. Adopt a smaller welding current to reduce heat input and avoid the generation of welding cracks.

[0062] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and its concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A high-strength wear-resistant steel narrow gap hot wire TIG-electrode hybrid welding method, which adopts a hybrid welding method of superimposing narrow gap hot wire TIG welding and manual electrode arc welding, characterized in that: The high-strength wear-resistant steel gap hot wire TIG-electrode composite welding method includes the following contents: S1. Welding groove processing: According to the welding characteristics of narrow gap hot wire TIG welding and the shape of the welding gun, the U-shaped groove is designed, and a blunt edge of 2 to 3 mm is left at the bottom; S2. The groove is removed by mechanical processing. Before welding, the oxides and impurities in the welding area of ​​the parent steel plate are removed by angle grinding, and industrial alcohol is used to wipe the interface until the metallic luster is exposed; S3. After the grooves are cut, the high-strength wear-resistant steel plates to be welded are placed in pairs, with the relative gap between the bottom blunt edges being 2 to 3 mm; S4, preheat the area to be welded before welding, the preheating temperature is 100-120℃; S5. Use narrow gap hot wire TIG welding method for base welding and filling welding, and use inert gas flow protection during welding; S6. When using narrow gap hot wire TIG welding for fill welding, increase the welding current by 20 to 60A, and end the fill welding until the distance from the top surface of the groove is 7 to 8 mm; S7. Use manual arc welding to weld the cap weld from the TIG filler weld bead to the top surface of the groove; S8. After the narrow gap hot wire TIG arc welding and manual electrode arc welding hybrid welding is completed, use insulation cotton to cover the weld joint to reduce the cooling rate of the weld joint.

2. The method for high-strength wear-resistant steel narrow gap hot wire TIG-electrode hybrid welding according to claim 1 is characterized in that: The narrow gap hot wire TIG welding in step S5 uses JQ.TG50 carbon steel argon arc welding wire as welding material, the welding wire tensile strength Rm>490MPa, and the -30°C impact energy Kv2>27J.

3. The high-strength wear-resistant steel narrow gap hot wire TIG-electrode hybrid welding method according to claim 1 is characterized in that: In the step S5, the welding current of the narrow gap hot wire TIG welding is 110-180A, the welding voltage is 12-16V, the welding speed is 100-150mm / min, and the swing width is 2mm.

4. The high-strength wear-resistant steel narrow gap hot wire TIG-electrode hybrid welding method according to claim 1 is characterized in that: The inert gas in step S5 uses high-purity argon as the shielding gas. Before welding, the weld is blown for 3 seconds to fill the bottom of the weld with argon, and then the narrow gap hot wire TIG root welding operation is performed.

5. The high-strength wear-resistant steel narrow gap hot wire TIG-electrode hybrid welding method according to claim 1 is characterized in that: The cap welding in step S7 includes cap corrosion resistant layer welding and cap wear resistant layer welding. The cap corrosion resistant layer is welded on the TIG filling welding bead, and the cap wear resistant layer is welded on the cap corrosion resistant layer to the top surface of the groove.

6. The high-strength wear-resistant steel narrow gap hot wire TIG-electrode hybrid welding method according to claim 5 is characterized in that: The welding of the cover corrosion-resistant layer adopts manual arc welding, and the welding material used is A132 stainless steel welding rod, the specification is a small-size welding rod with a diameter of 3.2mm, the welding current is 70-90A, the welding voltage is 14-16V, and the welding speed is 100-120mm / min.

7. The high-strength wear-resistant steel narrow gap hot wire TIG-electrode hybrid welding method according to claim 5 is characterized in that: The cover wear-resistant layer is welded by manual arc welding, and the welding material used is D167 low-hydrogen sodium coated manganese silicon type welding rod, the specification is a small-size welding rod with a diameter of 3.2mm, a welding current of 85-100A, a welding voltage of 16-20V, and a welding speed of 100-120mm / min.

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