Submerged arc additive manufacturing method for MIG heat source single filament

Abstract

The invention provides an MIG heat source single filament submerged arc additive manufacturing method. The MIG heat source single filament submerged arc additive manufacturing method comprises the following steps that S1, additive pretreatment is conducted; s2, preparing additional material equipment; s3, additive materials are prepared; s4, adjusting the posture of the welding gun; s5, material adding operation is conducted, material adding is conducted through welding wire burying with protective welding flux and welding gun arcing wire feeding, during the period, the current of an MIG heat source ranges from 150 A to 260 A, the voltage ranges from 25 V to 36 V, the advancing speed of a welding gun ranges from 0.15 m / min to 0.25 m / min, the interlayer temperature is not larger than 100 DEG C, and slag crust is cleaned after one layer of material adding is completed; by means of the method, MIG filament submerged arc additive manufacturing of the doped ceramic particle Fe-based additive can be achieved under the condition that submerged arc welding equipment does not exist. Compared with conventional wire electric arc additive manufacturing, the defects of air holes, incomplete fusion and the like are reduced, and forming is better; the welding flux is adopted for protection, smoke and dust are avoided, the electric arc additive manufacturing environment of operators is greatly improved, metal poisoning is avoided, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of additive manufacturing, and in particular to a MIG heat source single filament submerged arc additive manufacturing method. Background Art

[0002] Mechanical parts made with Fe as the main component can significantly reduce production costs. Compared with traditional milling processing, additive manufacturing is environmentally friendly, has a high material utilization rate, simple process, and short production cycle, and is more suitable for processing and manufacturing metal parts.

[0003] The arc additive manufacturing of metal Fe wire doped with ceramic particles has poor formability, and the process parameters are difficult to control. It is easy to have defects such as pores, slag inclusions, and unfused materials, resulting in poor mechanical properties of the additive materials or even failure to form them. On the other hand, the large amount of smoke generated by the arc additive manufacturing of gas-shielded wire materials often causes poisoning of operators.

[0004] Due to the good thermal conductivity of Q235 steel, during conventional wire arc additive manufacturing, heat is quickly conducted away from the heating zone, and pores are prone to occur. In addition, the arc additive manufacturing of Fe-based wires doped with ceramic particles has poor fluidity and poor formability, and the ceramic particles and Fe are not well combined. During the additive manufacturing process, the ceramic decomposes to produce pores and cause large spatter. During the conventional wire arc additive manufacturing process, due to the large welding current and large heat input, the Fe-based wire doped with ceramic particles melts in large quantities and mixes with the lower weld under the stirring action of the arc force. During this period, it will experience multiple uneven thermal cycles, which has a great impact on the uniformity of the structure of the additive parts and is prone to forming columnar crystals.

[0005] Therefore, a MIG heat source single-filament submerged arc additive manufacturing method is urgently needed. Through the metallurgical action of the submerged arc agent, slag is formed to solve the problem of poor forming. Secondly, the molten pool is protected, and protective gas is introduced to reduce the oxygen partial pressure in the submerged arc agent and reduce the generation of pores. Summary of the invention

[0006] The purpose of the present invention is to provide a MIG heat source single filament submerged arc additive manufacturing method to solve the problems existing in the above-mentioned prior art.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a MIG heat source single filament submerged arc additive manufacturing method, comprising the following steps:

[0009] S1. Additive pre-processing;

[0010] S2. Prepare additive equipment;

[0011] S3. Prepare additive materials;

[0012] S4. Adjust the welding gun posture;

[0013] S5. Perform additive operation, bury the welding wire with protective flux, start the arc and feed the wire with the welding gun to add material. During this period, the current of the MIG heat source is 150-260A, the voltage is 25-36V, the welding gun travel speed is 0.15-0.25m / min, the interlayer temperature is not more than 100℃, and the slag shell is cleaned after one layer of additive is completed.

[0014] Preferably, step S1 specifically includes: polishing to remove oxides on the surface of the substrate to expose the metallic luster, cleaning the surface with alcohol, and preheating the substrate.

[0015] Preferably, the substrate is made of Q235 steel.

[0016] Preferably, step S2 specifically includes: preparing an additive power source and a welding gun, the welding gun having a dry extension length of 12-16 mm and an arc length of 12-16 mm.

[0017] Preferably, step S3 specifically comprises: preparing welding wire and shielding flux, wherein the welding wire is a homemade ceramic-doped Fe welding wire with a diameter of 1.6 mm, and the shielding flux is HJ260 molten flux.

[0018] Preferably, the particle size of the protective flux is 8-25 mesh, and the drying time in the protective gas is 2 hours at a drying temperature of 350°C.

[0019] Preferably, step S4 specifically includes: making the welding wire take an advancing angle so that the welding wire is perpendicular to the substrate.

[0020] Preferably, in step S5, the protective gas needs to be turned on during the material addition process.

[0021] Preferably, in step S5, the number of additive layers is 20.

[0022] Compared with the prior art, the present invention has achieved the following beneficial technical effects:

[0023] The present invention provides a MIG heat source single filament submerged arc additive manufacturing method, comprising the following steps: S1. additive pretreatment; S2. preparing additive equipment; S3. preparing additive materials; S4. adjusting the welding gun posture; S5. performing additive operation, burying the welding wire with protective flux, arcing and feeding the welding gun for additive, during which the current of the MIG heat source is 150-260A, the voltage is 25-36V, the welding gun travel speed is 0.15-0.25m / min, the interlayer temperature is not greater than 100°C, and the slag shell is cleaned after one layer of additive is completed; the above method can realize the MIG filament submerged arc electric arc additive manufacturing of Fe-based additives doped with ceramic particles without submerged arc welding equipment. Compared with conventional wire arc additive manufacturing, it reduces defects such as pores and unfused and has better molding; adopts flux protection to achieve smoke-free, greatly improves the arc additive manufacturing environment of the operator, avoids metal poisoning and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 A schematic diagram of submerged arc additive manufacturing of Fe-based wires doped with ceramic particles in a MIG heat source single-filament submerged arc additive manufacturing method provided by the present invention;

[0026] Figure 2 Actual picture of the additive part manufactured by MIG direct additive manufacturing;

[0027] Figure 3 A physical picture of an additive part manufactured by MIG filament submerged arc additive manufacturing in a MIG heat source single filament submerged arc additive manufacturing method provided by the present invention;

[0028] Among them, 1 is a substrate, 2 is a protective flux, 3 is a welding gun, 4 is a welding wire, 5 is an additive, and 6 is a baffle. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0030] The purpose of the present invention is to provide a MIG heat source single filament submerged arc additive manufacturing method to solve the problems existing in the prior art.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Embodiment 1:

[0033] This embodiment provides a MIG heat source single filament submerged arc additive manufacturing method, comprising the following steps:

[0034] S1. Additive pre-treatment; the substrate 1 is made of Q235 steel, the oxide on the surface of the substrate 1 is polished to remove the metal luster, the surface is cleaned with alcohol, and the substrate 1 is preheated;

[0035] S2. Prepare additive equipment; prepare additive power supply and welding gun 3. The additive power supply adopts Panasonic's TAWERS welding power supply. The dry extension length of welding gun 3 is 12-16mm, and the arc length is 12-16mm.

[0036] S3. Prepare additive materials; prepare welding wire 4 and protective flux 2, welding wire 4 is a homemade ceramic-doped Fe welding wire with a diameter of 1.6 mm, protective flux 2 is HJ260 smelting flux, protective flux 2 has a particle size of 8-25 mesh, and is dried in a protective gas for 2 hours at a drying temperature of 350 ° C;

[0037] S4. Adjust the welding gun posture; make the welding wire 4 take the forward angle, and the welding wire 4 is perpendicular to the substrate 1;

[0038] S5. Perform additive operation, bury the welding wire with protective flux, start the arc and feed the wire with the welding gun for additive process. The protective gas needs to be turned on during the additive process. During this period, the current of the MIG heat source is 150-260A, the voltage is 25-36V, the welding gun travel speed is 0.15-0.25m / min, the interlayer temperature is not more than 100℃, and the slag shell is cleaned after one layer of additive is completed. The number of additive layers is 20.

[0039] The present invention provides a MIG heat source single filament submerged arc additive manufacturing method. In the process of arc additive of Fe-based wire doped with ceramic particles, due to the coverage of flux, the protection effect of the additive molten pool is good, the heat dissipation of steel is slowed down, the cooling rate is reduced, and the hydrogen in the molten pool can escape more fully, thereby greatly reducing pores; the arc formed by the MIG heat source filament is highly efficient, so that the bottom of the additive part is fully fused with the matrix, and the flux melts and covers the surface of the additive part, ensuring that the surface of the additive part is well formed and the slag shell is simple to remove, solving the problems of unfused and slag inclusions. Compared with conventional arc additive manufacturing, the submerged arc additive manufacturing of Fe-based wire doped with ceramic particles of the present invention reduces heat input, increases flux protection, and provides better formability.

[0040] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A MIG heat source single filament submerged arc additive manufacturing method, characterized in that: The following steps are involved: S1. Additive pre-processing; S2. Prepare additive equipment; S3. Prepare additive materials; S4. Adjust the welding gun posture; S5. Perform additive operation, bury the welding wire with protective flux, start the arc and feed the wire with the welding gun to add material. During this period, the current of the MIG heat source is 150-260A, the voltage is 25-36V, the welding gun travel speed is 0.15-0.25m / min, the interlayer temperature is not more than 100℃, and the slag shell is cleaned after one layer of additive is completed.

2. The MIG heat source single filament submerged arc additive manufacturing method according to claim 1, characterized in that: Step S1 specifically includes: polishing to remove oxides on the surface of the substrate to expose the metallic luster, cleaning the surface with alcohol, and preheating the substrate.

3. The MIG heat source single filament submerged arc additive manufacturing method according to claim 2, characterized in that: The base plate is made of Q235 steel.

4. The MIG heat source single filament submerged arc additive manufacturing method according to claim 1, characterized in that: Step S2 specifically includes: preparing an additive power source and a welding gun, wherein the welding gun has a dry extension length of 12-16 mm and an arc length of 12-16 mm.

5. The MIG heat source single filament submerged arc additive manufacturing method according to claim 1, characterized in that: Step S3 specifically includes: preparing welding wire and shielding flux, the welding wire is a homemade ceramic-doped Fe welding wire with a diameter of 1.6 mm, and the shielding flux is HJ260 molten flux.

6. The MIG heat source single filament submerged arc additive manufacturing method according to claim 5, characterized in that: The particle size of the protective flux is 8-25 mesh, and the drying time in the protective gas is 2 hours, and the drying temperature is 350°C.

7. The MIG heat source single filament submerged arc additive manufacturing method according to claim 1, characterized in that: Step S4 specifically includes: making the welding wire take an advancing angle so that the welding wire is perpendicular to the substrate.

8. The MIG heat source single filament submerged arc additive manufacturing method according to claim 1, characterized in that: In step S5, the protective gas needs to be turned on during the additive process.

9. The MIG heat source single filament submerged arc additive manufacturing method according to claim 1, characterized in that: In step S5, the number of additive layers is 20.

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