Circular tube surface surfacing method and surfacing circular tube

Abstract

The invention provides a circular tube surface surfacing method and a surfacing circular tube, and belongs to the technical field of surfacing. The round tube surface surfacing method comprises the following steps that an ERCCoCr-A welding wire is adopted for conducting surfacing on a round tube, and a surfacing round tube is obtained; during surfacing, the circular tube is horizontally placed, and performs unidirectional translational motion along the central axis and unidirectional rotational motion around the central axis of the circular tube at the same time; during surfacing, a welding gun swings left and right on the outer side of the circular tube and perpendicular to the central axis of the circular tube; the swing frequency of the left-right swing ranges from 2.8 Hz to 3.5 Hz. The ERCCoCr-A welding wire is used as a surfacing material, so that the hardness of components can be increased, and meanwhile, the components have heat resistance, corrosion resistance and wear resistance; by adjusting the swing frequency of the welding gun in the surfacing process, a welding bead formed by surfacing is neat, lines are clear, and the heat resistance, corrosion resistance and wear resistance of the surfacing round pipe are improved.

Description

Technical Field

[0001] The invention relates to the technical field of cladding, and in particular to a round tube surface cladding method and a cladding round tube. Background Art

[0002] With the improvement of electric power, chemical industry, water conservancy, building materials, coal, nuclear power, military industry and China's industrial technology and the adjustment of national industrial policies, surfacing technology has been widely used in the industrial field, especially in the heavy industry field, and plays a pivotal role in the iron and steel metallurgy, mining, machinery manufacturing and other industries. Surfacing has developed from the original simple repair to the process link of new product manufacturing and old product remanufacturing. The large-scale development of the surfacing industry has also driven the large-scale consumption of surfacing materials. So far, the manufacturing industry of surfacing materials has also become a relatively independent large-scale industry. In recent years, surfacing technology has become a research hotspot for domestic scholars. The development of new surfacing technical means and intelligent process control has promoted the development of surfacing technology towards the direction of correct forming. It can prepare important surfacing layers with special properties such as wear resistance, heat resistance, and corrosion resistance on the basis of common materials.

[0003] During the working process of the central oxygen tube, the outer surface is usually in contact with the high-speed flowing water-coal slurry, and oxygen is blown outward from the inside. With the development of industry, the working internal environment of the boiler is becoming more and more complicated. In the combustion chamber, the central tube is not only eroded and worn by the water-coal slurry, but also corroded by the sulfur-containing gas. The higher the temperature, the more serious the corrosion. At present, nickel-based materials such as Inconel-600, Inconel-625, Incoloy-800H, Incoloy-825, etc. are commonly used in the central oxygen tube. These materials usually have good anti-corrosion properties, but the hardness is not high. Under the erosion of high-speed coal powder, the wear is more serious. In order to improve the hardness of the outer surface of the round tube and surfacing high-hardness materials on its surface, a large heat input is generally required, and a large heat input will lead to unsightly weld bead formation, excessive penetration, stress concentration, cracks, and then reduce the heat resistance, corrosion resistance and wear resistance of the surfacing round tube. Therefore, how to simultaneously improve the heat resistance, corrosion resistance and wear resistance of the surfacing round tube has become a technical problem to be solved in this field. Summary of the invention

[0004] The object of the present invention is to provide a method for surfacing a round tube surface and a surfacing round tube. The method for surfacing a round tube surface provided by the present invention can improve the heat resistance, corrosion resistance and wear resistance of the surfacing round tube.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for surfacing a round tube surface, comprising the following steps:

[0007] The round tube is clad by using ERCCoCr-A welding wire to obtain a clad round tube;

[0008] During the surfacing welding, the round tube is placed horizontally and performs unidirectional translational movement along the central axis and unidirectional rotational movement around the central axis of the round tube at the same time;

[0009] During the surfacing welding, the welding gun swings left and right perpendicular to the central axis of the round tube outside the round tube; the swing frequency of the left and right swing is 2.8-3.5 Hz.

[0010] Preferably, the diameter of the round tube is 38-350 mm, and the wall thickness of the round tube is 5-50 mm.

[0011] Preferably, the speed of the translational motion is 0.1-0.3 mm / s; the rotational speed of the rotational motion is 4-6 mm / s.

[0012] Preferably, the flow rate of the shielding gas during the surfacing welding is 15 to 20 L / min.

[0013] Preferably, during the surfacing welding, the distance between the muzzle of the welding gun and the round pipe is 10-20 mm.

[0014] Preferably, during the surfacing welding, the distance between the muzzle of the welding gun and the swing axis of the welding gun is 280-340 mm.

[0015] Preferably, the surfacing voltage during the surfacing welding is 17-19V, and the surfacing current is 95-110A.

[0016] The present invention also provides a cladding round tube, which is obtained by cladding using the method described in the above technical solution. The cladding round tube comprises a round tube and a cladding layer covering the outside of the round tube.

[0017] Preferably, the weld width of the cladding round tube is 10-15 mm, and the weld overlap of the cladding round tube is 3-8 mm.

[0018] Preferably, the thickness of the surfacing layer of the surfacing round pipe is ≥1.5 mm.

[0019] The present invention provides a method for surfacing the surface of a round tube, comprising the following steps: using ERCCoCr-A welding wire to surfacing the round tube to obtain a surfacing round tube; during the surfacing, the round tube is placed horizontally, and unidirectionally translates along the central axis while unidirectionally rotating around the central axis of the round tube; during the surfacing, the welding gun swings left and right perpendicular to the central axis of the round tube outside the round tube; the swing frequency of the left and right swing is 2.8-3.5Hz. The present invention uses ERCCoCr-A welding wire as a surfacing material to surfacing the round tube, and utilizes the high hardness of the cobalt-based alloy (ERCCoCr-A) to not only increase the hardness of the component, but also have heat resistance, corrosion resistance and wear resistance; by adjusting the swing frequency of the welding gun during the surfacing process, the weld bead formed by the surfacing is neat, the texture is clear, and it is not easy to produce defects, thereby improving the heat resistance, corrosion resistance and wear resistance of the surfacing round tube. The results of the embodiment show that the weld bead on the surface of the surfacing round tube prepared by the preparation method provided by the present invention is neat and flat, the texture is clear, the hardness of the surfacing layer reaches above HRC40, and the hardness of the surfacing metal on the surface of the surfacing round tube can still be maintained above HRC40 when the external environment is 800°C, and it has good heat resistance, corrosion resistance and wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The cross-sectional structural dimension diagram of the cladding round pipe in Example 1 of the present invention;

[0021] Figure 2 This is a side structural dimension diagram of the cladding round tube in Example 1 of the present invention. DETAILED DESCRIPTION

[0022] The present invention provides a method for surfacing a round tube surface, comprising the following steps:

[0023] Using ERCCoCr-A welding wire to perform cladding welding on the round tube to obtain a cladding round tube;

[0024] During the surfacing welding, the round tube is placed horizontally and performs unidirectional translational movement along the central axis and unidirectional rotational movement around the central axis of the round tube at the same time;

[0025] During the surfacing welding, the welding gun swings left and right perpendicular to the central axis of the round tube outside the round tube; the swing frequency of the left and right swing is 2.8-3.5 Hz.

[0026] The present invention adopts ERCCoCr-A welding wire to perform surfacing welding on the round tube to obtain the surfacing round tube.

[0027] In the present invention, the diameter of the round tube is preferably 38-350 mm, more preferably 60-350 mm; the wall thickness of the round tube is preferably 5-50 mm, more preferably 10-30 mm. The present invention limits the diameter and wall thickness of the round tube to the above ranges, which is beneficial to subsequent surfacing.

[0028] In the present invention, the material of the round tube is preferably Inconel 600, Incoloy 800H or Incoloy 825. The present invention limits the material of the round tube to the above types to improve the overall anti-corrosion performance of the cladding round tube.

[0029] In the present invention, the round tube is preferably pretreated before use. In the present invention, the pretreatment is preferably polishing the surface of the round tube; the tool used for polishing is preferably a louver wheel. The present invention can remove impurities such as rust, scale and oil stains on the surface of the round tube through polishing, which is conducive to subsequent surfacing.

[0030] In the present invention, the alloy composition of the ERCCoCr-A welding wire preferably includes, by mass percentage: C1.00%, Si 1.50%, Cr 30%, S 0.01%, P 0.005%, Fe 3.00%, W 5.4%, Mo 0.01%, Ni 2.20%, Mn 0.80% and the balance Co. The present invention limits the alloy composition of the ERCCoCr-A welding wire to the above range, and utilizes the large amount of Co element contained in the ERCCoCr-A welding wire. The heat resistance, corrosion resistance and wear resistance of the surfacing surface are improved; the large amount of Cr element contained in the ERCCoCr-A welding wire is utilized to improve the oxidation resistance and corrosion resistance of the surfacing layer, and prevent the erosion of oxygen and other harmful substances; the small amount of W element contained in the ERCCoCr-A welding wire is utilized to further enhance the corrosion resistance of the alloy, while improving the high temperature strength.

[0031] In an embodiment of the present invention, the wire diameter of the ERCCoCr-A welding wire is preferably 1.6 mm.

[0032] In the present invention, during the surfacing, the round tube is placed horizontally and performs unidirectional translation along the central axis and unidirectional rotation around the central axis of the round tube at the same time.

[0033] In the present invention, the speed of the translational motion is preferably 0.1-0.3 mm / s, more preferably 0.2 mm / s; the rotational speed of the rotational motion is preferably 4-6 mm / s, more preferably 5 mm / s. The present invention limits the speed of the translational motion and the rotational speed of the rotational motion to the above ranges to ensure that the weld bead of the cladding round pipe has a good overlap and thickness, thereby improving the heat resistance, corrosion resistance and wear resistance of the cladding round pipe.

[0034] In the present invention, during the cladding, the welding gun swings left and right perpendicular to the central axis of the round tube outside the round tube; the swing frequency of the left and right swing is 2.8 to 3.5 Hz, preferably 3.0 to 3.2 Hz. The present invention limits the frequency of the left and right swing to the above range to ensure that the weld is neat, the texture is clear, and defects are not easy to occur, thereby improving the corrosion resistance of the cladding round tube.

[0035] In the present invention, the initial position of the welding gun is preferably one end of the round tube. The present invention sets the initial position of the welding gun at one end of the round tube, and realizes surfacing welding on the entire surface of the round tube through translation and rotation of the round tube.

[0036] In the present invention, the flow rate of the shielding gas during the cladding is preferably 15 to 20 L / min, more preferably 16 to 18 L / min. In the present invention, the shielding gas plays a protective role on the weld bead. If the flow rate is too small, the air cannot be exhausted, which easily causes the weld bead to oxidize, and the slag discharge of the molten pool is not clean. If the flow rate of the shielding gas is too large, the heat of the molten pool will be increased, resulting in appearance defects of the weld bead. The present invention limits the flow rate of the shielding gas to the above range to obtain a good weld bead, avoid the generation of defects, and thus ensure the heat resistance, corrosion resistance and wear resistance of the cladding round pipe.

[0037] In the present invention, the shielding gas is preferably a mixed gas of argon and oxygen; the volume percentage of oxygen in the mixed gas is preferably 0.2-0.6%, more preferably 0.4%. The present invention limits the type and ratio of the shielding gas to the above range to protect the weld from oxidation.

[0038] In the present invention, the distance between the muzzle of the welding gun and the round pipe during the cladding is preferably 10 to 20 mm, more preferably 12 to 18 mm, and further preferably 15 mm. The present invention limits the distance between the muzzle of the welding gun and the round pipe to the above range to ensure a good gas atmosphere, ensure the flatness of the weld, avoid the generation of defects, and improve the corrosion resistance of the cladding round pipe.

[0039] In the present invention, the distance between the muzzle of the welding gun and the swing axis of the welding gun during the cladding is preferably 280-340 mm, more preferably 300-320 mm, and further preferably 310 mm. The present invention limits the distance between the muzzle of the welding gun and the swing axis of the welding gun to the above range, so that the width of the weld can be controlled and the welding layer of the cladding round pipe can be kept flat, which is beneficial to improving the heat resistance, corrosion resistance and wear resistance of the cladding round pipe.

[0040] In the present invention, the surfacing voltage during surfacing is preferably 17-19V, more preferably 18V; the surfacing current during surfacing is preferably 95-110A, more preferably 100-105A. The present invention controls the wire feeding speed and heat by controlling the voltage and current of surfacing. The greater the current, the faster the wire feeding, and the relative heat will also increase. The voltage controls the heat, and the greater the voltage, the higher the heat. The present invention limits the surfacing voltage and current to the above range to ensure the quality of the welding layer, which is beneficial to improving the heat resistance, corrosion resistance and wear resistance of the surfacing round pipe.

[0041] The present invention adopts ERCCoCr-A welding wire as a surfacing material to perform surfacing welding on a round pipe, and utilizes the high hardness of the cobalt-based alloy (ERCCoCr-A) to increase the hardness of the component while also having heat resistance, corrosion resistance and wear resistance; by adjusting the swing frequency of the welding gun during the surfacing welding process, the weld bead formed by the surfacing welding is neat, the texture is clear, and it is not easy to produce defects, thereby improving the heat resistance, corrosion resistance and wear resistance of the surfacing round pipe.

[0042] The present invention also provides a cladding round tube, which is obtained by cladding using the method described in the above technical solution. The cladding round tube comprises a round tube and a cladding layer covering the outside of the round tube.

[0043] In the present invention, the bead width of the cladding round pipe is preferably 10-15 mm, more preferably 12-14 mm, and further preferably 13 mm; the bead overlap of the cladding round pipe is preferably 3-8 mm, and more preferably 5 mm. The present invention limits the bead width and the bead overlap to the above ranges to ensure the flatness of the cladding layer of the cladding round pipe, is not prone to defects, and improves the heat resistance, corrosion resistance and wear resistance of the cladding round pipe.

[0044] In the present invention, the thickness of the cladding layer of the cladding round pipe is preferably ≥1.5 mm, more preferably 2 to 3 mm. The present invention limits the thickness of the cladding layer to the above range, which can help improve the heat resistance, corrosion resistance and wear resistance of the cladding round pipe.

[0045] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] Example 1

[0047] A method for surfacing welding on the surface of a round tube:

[0048] The round tube is surfacing-welded by using an ERCCoCr-A welding wire with a wire diameter of 1.6 mm to obtain a surfacing-welded round tube; the alloy composition of the ERCCoCr-A welding wire is as follows in terms of mass percentage: C 1.00%, Si 1.50%, Cr 30%, S 0.01%, P0.005%, Fe 3.00%, W 5.4%, Mo 0.01%, Ni 2.20%, Mn 0.80% and the balance Co; the round tube is polished and ground by using a louver wheel before use; the flow rate of the protective gas during the surfacing is 18 L / min; the distance between the muzzle of the welding gun and the swing axis of the welding gun during the surfacing is 310 mm; the distance between the muzzle of the welding gun and the round tube during the surfacing is 15 mm; the surfacing voltage during the surfacing is 18 V and the surfacing current is 105 A;

[0049] The round tube is clamped horizontally on the bracket, so that the welding gun is at one end of the round tube and perpendicular to the central axis of the round tube on the outside of the round tube; the material of the round tube is Incoloy800H, the diameter of the round tube is 250mm, and the wall thickness of the round tube is 10mm;

[0050] During surfacing welding, the round tube is subjected to unidirectional translational movement along the central axis and unidirectional rotational movement around the central axis of the round tube at the same time; the translational speed of the translational movement is 0.2 mm / s; the rotational speed of the rotational movement is 5 mm / s;

[0051] During surfacing welding, the welding gun swings left and right perpendicular to the central axis of the round tube outside the round tube; the swing frequency of the left and right swing is 3.0 Hz.

[0052] The cladding round tube obtained in this embodiment consists of a round tube and a cladding layer covering the outside of the round tube;

[0053] The weld width of the cladding round pipe is 13 mm; the weld overlap of the cladding round pipe is 5 mm; and the cladding layer thickness of the cladding round pipe is 2 mm.

[0054] Figure 1 The cross-sectional structural dimension diagram of the cladding round pipe in this embodiment is shown in FIG. Figure 2 The side structural dimension diagram of the cladding round pipe in this embodiment is shown in FIG. Figure 1 and Figure 2 It can be seen that the cladding round tube consists of a round tube and a cladding layer covering the outside of the round tube. The diameter of the round tube is 250 mm, the wall thickness of the round tube is 10 mm, and the thickness of the cladding layer is 2 mm. The diameter of the cladding round tube is 254 mm.

[0055] Use ultrasonic thickness gauge and metal surface spectrum analyzer to detect the weld thickness and surface composition of the weld layer on the melt surface; perform VT and RT tests on the entire weld layer; and use Rockwell hardness tester to perform hardness test.

[0056] In Example 1, the surfacing thickness of the surfacing round pipe is 2 mm, the surface composition of the surfacing layer is Cr 28%, Fe 5.30%, W 5.3%, Ni 2.0% and the balance Co, the weld bead on the surface of the surfacing round pipe is neat and flat, the hardness of the surfacing layer is 45 HRC, and the hardness of the surfacing metal on the surface of the surfacing round pipe at an external environment of 800° C. is 40 HRC.

[0057] The weld bead on the surface of the surfacing round pipe obtained by surfacing welding using the method provided by the present invention is neat and flat, with clear textures, and the hardness of the surfacing layer reaches above HRC40. When the external environment is 800°C, the hardness of the surfacing metal on the surface of the surfacing round pipe can still be maintained above HRC40, and it has good heat resistance, corrosion resistance and wear resistance.

[0058] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for surfacing a round tube, comprising the following steps: The round tube is clad by using ERCCoCr-A welding wire to obtain a clad round tube; During the surfacing welding, the round tube is placed horizontally and performs unidirectional translational movement along the central axis and unidirectional rotational movement around the central axis of the round tube at the same time; During the surfacing welding, the welding gun swings left and right perpendicular to the central axis of the round tube outside the round tube; the swing frequency of the left and right swing is 2.8-3.5 Hz.

2. The method according to claim 1, characterized in that The diameter of the round tube is 38-350 mm, and the wall thickness of the round tube is 5-50 mm.

3. The method according to claim 1, characterized in that The speed of the translational motion is 0.1-0.3 mm / s; the rotational speed of the rotational motion is 4-6 mm / s.

4. The method according to claim 1, characterized in that The flow rate of the protective gas during the surfacing welding is 15 to 20 L / min.

5. The method according to claim 1, characterized in that During the surfacing welding, the distance between the nozzle of the welding gun and the round pipe is 10-20 mm.

6. The method according to claim 5, characterized in that During the surfacing welding, the distance between the gun muzzle and the swing axis of the welding gun is 280-340 mm.

7. The method according to claim 1, characterized in that The surfacing welding voltage is 17-19V, and the surfacing welding current is 95-110A.

8. A cladding round pipe obtained by cladding the pipe using the method according to any one of claims 1 to 7, the cladding round pipe comprising a round pipe and a cladding layer covering the outside of the round pipe.

9. The cladding round pipe according to claim 8, characterized in that: The weld width of the cladding round pipe is 10-15 mm, and the overlap amount of the weld of the cladding round pipe is 3-8 mm.

10. The cladding round pipe according to claim 8 or 9, characterized in that: The thickness of the cladding layer of the cladding round pipe is ≥1.5 mm.

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