High-toughness high-manganese steel flux-cored wire for laser cladding and preparation method of high-toughness high-manganese steel flux-cored wire

Abstract

The invention discloses a high-toughness high-manganese steel flux-cored wire for laser cladding and a preparation method thereof, the high-toughness high-manganese steel flux-cored wire for laser cladding comprises a welding skin and a flux core, the welding skin is a low-carbon steel strip, and the flux core comprises Mn, C, Si, Mo and the balance Fe and inevitable impurities. Components for generating shielding gas in the flux core are removed, air holes are prevented from being left when the generated shielding gas overflows from a molten pool, and a shielding gas device of the laser can prevent a coating from being oxidized; low-carbon steel is used for manufacturing the welding skin, and a proper amount of manganese and carbon elements are added into the flux core, so that the coating subjected to melting, mixing and solidification can maintain the composition proportion of the high-manganese steel, and further the wear resistance of the coating is maintained; and meanwhile, interference of work hardening generated during production, transportation, processing and use of the high-manganese steel welding skin on wire filling laser cladding is avoided.

Description

Technical Field

[0001] The invention relates to a flux-cored welding wire, in particular to a high-toughness high-manganese steel flux-cored welding wire for laser cladding and a preparation method thereof, belonging to the technical field of laser cladding material preparation. Background Art

[0002] The development of science and technology and harsh working conditions have put forward higher requirements on the wear resistance of metal equipment parts. Various laser cladding technologies for the purpose of manufacturing wear-resistant coatings have developed rapidly, among which wire-filled laser cladding has a cost-effective advantage that cannot be ignored.

[0003] Laser cladding is an advanced technology for repairing and surface modifying metal products. Specifically, a laser beam is used to irradiate the substrate and functional materials, so that the melted functional materials and the substrate form a molten pool together, and finally a cladding coating with good metallurgical bonding and better performance is obtained. Wire-filled laser cladding uses wire-shaped functional materials for cladding, which is a new field in laser cladding. It has high material utilization, good component stability, little impact on equipment, and broad prospects. Among various types of wear-resistant materials, high manganese steel is favored by wear-resistant coating producers for its low price and excellent heavy-load wear resistance.

[0004] In the prior art, a patent with publication number CN113458654A discloses an ultra-low temperature high manganese steel welding wire, welding rod and its preparation method. The welding wire greatly reduces the use of Ni. Through C, Mn, Cr, and Mo alloying, the cladding metal formed by the welding material forms an austenite structure, which produces excellent performance, saves Ni resources, and reduces costs. On the basis of the welding wire, the welding rod is equipped with a special low-component coating, and the cladding metal formed has excellent performance and fully meets the use requirements of liquefied natural gas storage tanks. However, the existing high manganese steel welding wire is often directly made of high manganese steel welding skin wrapped with a flux core that can generate protective gas. On the one hand, the existing high manganese steel welding wire is often used in the electric welding industry, and the working environment of the electric welding industry is usually difficult to provide protective gas, so it is necessary to use a flux core that can spontaneously generate protective gas. However, laser cladding needs to undergo rapid melting and rapid solidification processes, and the demand for anti-oxidation is high, so laser cladding equipment often has its own gas protection device. In this case, the effect of the shielding gas generated by the welding wire itself will be very limited. Even when the shielding gas generated by the flux core overflows from the molten pool, it will leave pores in the coating, greatly weakening the coating performance. On the other hand, the excellent work hardening ability of high manganese steel makes the existing welding wire that directly uses high manganese steel as the weld skin inevitably harden during production, transportation, processing and use, making it difficult to carry out wire laser cladding stably. Summary of the invention

[0005] The object of the present invention is to solve at least one of the above technical problems and to provide a high-toughness high-manganese steel flux-cored welding wire for laser cladding and a preparation method thereof.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions: A high-toughness high-manganese steel flux-cored welding wire for laser cladding, comprising a welding skin and a flux core, wherein the flux core is wrapped in the welding skin; The welding skin is a low-carbon steel strip. The components of the flux core include Mn, C, Si, Mo, and the balance is Fe and inevitable impurities. The components of the flux core include the following two types: When the low carbon steel strip of the weld skin is Q195 carbon structural steel, the flux core is composed of the following components by mass percentage: Mn: 36-44wt%; C: 2-3.5wt%; Si: 1-2wt%; Mo: 0.5-1.5wt%, the remainder is Fe and unavoidable impurities, and the sum of the above components is 100%; When the low carbon steel strip of the weld skin is Q235 carbon structural steel, the flux core is composed of the following components by mass percentage: Mn: 35-43wt%; C: 3-4wt%; Si: 0-1.5wt%; Mo: 0.5-1.5wt%, and the remainder is Fe and unavoidable impurities, and the sum of the above components is 100%.

[0007] As a further solution of the present invention, the flux core filling rate in the flux cored welding wire is 28-32wt%.

[0008] As a further solution of the present invention: the diameter of the flux-cored welding wire is φ1.0mm-φ3.0mm.

[0009] As a further solution of the present invention: the purity of Mn in the core is ≥99%, and the particle size is ≤0.3mm; the purity of C is ≥98%, and the particle size is ≤0.3mm; the purity of Si is ≥98%, and the particle size is ≤0.3mm; the purity of Mo is ≥99%, and the particle size is ≤0.3mm; and the purity of Fe is ≥99%, and the particle size is ≤0.3mm.

[0010] As a further solution of the present invention: after the flux-cored welding wire is subjected to filler wire laser cladding, the composition of the wear-resistant high-manganese steel coating prepared is: Mn: 10-14wt%, C: 0.9-1.5wt%; Si: <1wt%; P: <0.05wt%; S: <0.05wt%; Mo: 0.15-0.45wt%; the balance is iron and inevitable impurities.

[0011] A method for preparing a high-toughness high-manganese steel flux-cored welding wire for laser cladding, comprising the flux-cored welding wire, and the preparation method comprises the following steps: S1. When the low-carbon steel strip of the weld skin is preferably made of Q195 carbon steel, the following raw material powders are weighed according to mass percentage: Mn: 42-44%; C: 2-3.5%; Si: 1-2%; Mo: 0.5-1.5%, the remainder is Fe and unavoidable impurities, and the sum of the above components is 100%; S2. When the low-carbon steel strip of the weld skin is preferably made of Q235 carbon steel, the following raw material powders are weighed in mass percentage: Mn: 40-43%; C: 3-4%; Si: 1-2%; Mo: 0.5-1.5%, the remainder is Fe and unavoidable impurities, and the sum of the above components is 100%; S3, placing the raw material powder weighed in S1 in a vacuum heating furnace for heating to remove crystal water in the raw material; the dried raw material powder is fully mixed using a powder mixer to obtain a drug core; S4, using alcohol to remove the grease on the surface of the carbon steel strip in S1, and wrapping the flux core prepared in S2 in the steel strip through a flux-cored wire drawing device to form a process flux-cored wire; S5, performing the first drawing of the process flux-cored welding wire; S6. After the first drawing process is completed, the drawing is repeated multiple times to reduce the diameter of the flux-cored welding wire in turn until a flux-cored welding wire with a diameter of 1.0-3.0 mm is obtained.

[0012] S7, winding the workpieces with the required size in S6 in layers, so as to obtain the formed high manganese steel welding wire.

[0013] As a further solution of the present invention: in S7, the laser cladding application of the prepared high manganese steel welding wire requires external application of protective gas.

[0014] As a further solution of the present invention: the protective gas is high-purity argon.

[0015] As a further solution of the present invention: high manganese steel welding wire is suitable for the repair, surface modification and additive manufacturing of various crushers, high manganese rails, switches and bulldozers that are easily worn due to impact.

[0016] The beneficial effects of the present invention are: 1) The present invention ensures the toughness of the welding wire through the reasonable allocation of elements, reduces the interference of the hardening of the welding wire itself on the laser cladding of the filler wire, and ensures that the generated metal coating is a high manganese steel wear-resistant coating. In addition, the components used to generate gas in the flux core are removed, reducing pores; 2) The present invention removes the components of the shielding gas generated in the flux core to avoid leaving pores when the shielding gas overflows from the molten pool, and the shielding gas device provided by the laser can prevent oxidation of the coating; and uses low-carbon steel to make the weld skin, and adds appropriate amounts of manganese and carbon elements to the flux core to ensure that the coating can maintain the composition ratio of high manganese steel after melting, mixing, and solidification, thereby maintaining its wear resistance, and at the same time avoiding the interference of the work hardening of the high manganese steel weld skin during production, transportation, processing, and use with the wire filling laser cladding. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the cross-sectional structure of the flux-cored welding wire of the present invention; In the figure: 1. Steel strip, 2. Core. DETAILED DESCRIPTION

[0018] 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.

[0019] Embodiment 1, as Figure 1 As shown, this embodiment provides a high-toughness high-manganese steel flux-cored welding wire for laser cladding, comprising a welding skin 1 and a flux core 2, wherein the flux core 2 is wrapped in the welding skin 1; The welding skin 1 is a low-carbon steel strip, and the components of the flux core 2 include Mn, C, Si, Mo, and the balance is Fe and inevitable impurities; The low carbon steel strip of the weld skin 1 is Q235 carbon structural steel, and the flux core 2 is composed of the following components by mass percentage: Mn: 35-43wt%; C: 3-4wt%; Si: 0-1.5wt%; Mo: 0.5-1.5wt%, and the remainder is Fe and unavoidable impurities, and the sum of the above components is 100%.

[0020] Embodiment 2: This embodiment provides a high-toughness high-manganese steel flux-cored welding wire for laser cladding, comprising a welding skin 1 and a flux core 2, wherein the flux core 2 is wrapped in the welding skin 1; The welding skin 1 is a low-carbon steel strip, and the components of the flux core 2 include Mn, C, Si, Mo, and the balance is Fe and inevitable impurities; When the low carbon steel strip of the weld skin 1 is Q235 carbon structural steel, the flux core 2 is composed of the following components by mass percentage: Mn: 35-43wt%; C: 3-4wt%; Si: 0-1.5wt%; Mo: 0.5-1.5wt%, and the remainder is Fe and unavoidable impurities, and the sum of the above components is 100%.

[0021] In addition to all the technical features of the first embodiment, this embodiment also includes: The filling rate of the flux core 2 in the flux cored welding wire is 28-32 wt%.

[0022] The diameter of the flux-cored welding wire is φ1.0mm-φ3.0mm.

[0023] The Mn purity of the core 2 is ≥99%, and the particle size is ≤0.3mm; the C purity is ≥98%, and the particle size is ≤0.3mm; the Si purity is ≥98%, and the particle size is ≤0.3mm; the Mo purity is ≥99%, and the particle size is ≤0.3mm; and the Fe purity is ≥99%, and the particle size is ≤0.3mm.

[0024] After the flux-cored welding wire is subjected to filler wire laser cladding, the wear-resistant high-manganese steel coating prepared has the following composition: Mn: 10-14wt%, C: 0.9-1.5wt%; Si: <1wt%; P: <0.05wt%; S: <0.05wt%; Mo: 0.15-0.45wt%; the remainder is iron and inevitable impurities.

[0025] It should be noted that Mn: In order to ensure the performance of high manganese steel, it must have sufficient manganese content. When the manganese content is too low, a single austenite structure cannot be formed. The final Mn content of the high manganese steel welding wire of the present invention is 10-14wt%, which meets the requirements of producing a single austenite high manganese steel coating.

[0026] C: C is the element that most significantly improves the strength and hardness of steel among all elements. When the carbon content in steel is too low, it is insufficient to produce an effective work hardening effect; and when the carbon content is too high, a large amount of carbides will appear in the cast state, especially coarse carbides. Therefore, in order to avoid the precipitation of carbides, the carbon content must be controlled not to be too high. The final C content of the high manganese steel coating produced by the high manganese steel welding wire of the present invention is 0.9-1.5wt%. While meeting the requirements within this range, the C content in the flux core can be appropriately adjusted to meet the special requirements.

[0027] Si: Si and Mn have a combined deoxidation effect, which can reduce the oxygen content in the metal coating and prevent the formation of pores. Si will reduce the solubility of carbon in austenite, promote the precipitation of carbides, and reduce the wear resistance and impact toughness of steel. Therefore, the amount of silicon should be controlled within the lower limit of the specification.

[0028] Mo: The Mo element can inhibit the precipitation of carbides in steel. The addition of Mo in high manganese steel welding wire can improve the crack resistance and wear resistance of the coating.

[0029] P and S: P will reduce the impact toughness of steel and make castings prone to cracking, and S will increase the corrosiveness of steel and reduce the ductility and toughness of steel, so the content of P and S in steel should be reduced as much as possible. The present invention ensures that the content of P and S in the generated metal coating is within the lower limit of the specification, that is, S: <0.05wt%, P: <0.05wt% by reducing the content of P and S in the two parts of the welding wire, namely, the welding skin and the flux core.

[0030] Embodiment 3, a method for preparing a high-toughness high-manganese steel flux-cored welding wire for laser cladding, comprising a flux-cored welding wire, the preparation method comprising the following steps: S1. When the low-carbon steel strip of weld skin 1 is preferably made of Q195 carbon steel, the following raw material powders are weighed in mass percentage: Mn: 42-44%; C: 2-3.5%; Si: 1-2%; Mo: 0.5-1.5%, the remainder is Fe and unavoidable impurities, and the sum of the above components is 100%; S2. When the low-carbon steel strip of the weld skin 1 is preferably made of Q235 carbon steel, the following raw material powders are weighed in mass percentage: Mn: 40-43%; C: 3-4%; Si: 1-2%; Mo: 0.5-1.5%, the remainder is Fe and unavoidable impurities, and the sum of the above components is 100%; S3, placing the raw material powder weighed in S1 in a vacuum heating furnace for heating to remove crystal water in the raw material; the dried raw material powder is fully mixed using a powder mixer to obtain a core 2; S4, using alcohol to remove the grease on the surface of the carbon steel strip in S1, and wrapping the flux core 2 prepared in S2 in the steel strip through a flux-cored wire drawing device to form a process flux-cored wire; S5, performing the first drawing of the process flux-cored welding wire; S6. After the first drawing process is completed, the drawing is repeated multiple times to reduce the diameter of the flux-cored welding wire in turn until a flux-cored welding wire with a diameter of 1.0-3.0 mm is obtained.

[0031] S7, winding the workpieces with the required size in S6 in layers, so as to obtain the formed high manganese steel welding wire.

[0032] The laser cladding application of the prepared high manganese steel welding wire requires external application of shielding gas, which is high-purity argon gas. The components of shielding gas generated autonomously in the flux core 2 are removed, and external shielding gas is used instead, which prevents the gas generated by the flux core 2 from overflowing from the molten pool and leaving pores.

[0033] High manganese steel welding wire is suitable for the repair, surface modification and additive manufacturing of various crushers, high manganese rails, switches and bulldozers that are easily worn due to impact. It has a wide range of applications and can meet different usage requirements.

[0034] The welding wire specifically includes two parts: a weld skin 1 and a flux core 2. Low carbon steel is selected as the weld skin material to avoid the direct use of high manganese steel. By regulating the composition of the flux core 2, a high-toughness high manganese steel flux cored welding wire for laser cladding that can be used to manufacture a high manganese steel wear-resistant coating is realized. The components of the self-generated shielding gas in the flux core 2 are removed, and an external shielding gas is used instead, which avoids the gas generated by the flux core 2 from overflowing from the molten pool and leaving pores. Low carbon steel has good toughness and weak work hardening ability, which avoids the influence of the work hardening of the high manganese steel weld skin on the stability and accuracy of the filler wire laser cladding.

[0035] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0036] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A high-toughness high-manganese steel flux-cored welding wire for laser cladding, comprising a welding skin (1) and a flux core (2), wherein the flux core (2) is wrapped in the welding skin (1); characterized in that: The welding skin (1) is a low-carbon steel strip, and the components of the flux core (2) include Mn, C, Si, Mo, and the balance is Fe and inevitable impurities; The components of the drug core (2) include the following two types: When the low carbon steel strip of the welding skin (1) is Q195 carbon structural steel, the flux core (2) is composed of the following components by mass percentage: Mn: 36-44wt%; C: 2-3.5wt%; Si: 1-2wt%; Mo: 0.5-1.5wt%, and the remainder is Fe and unavoidable impurities, and the sum of the above components is 100%; When the low carbon steel strip of the welding skin (1) is Q235 carbon structural steel, the flux core (2) is composed of the following components by mass percentage: Mn: 35-43wt%; C: 3-4wt%; Si: 0-1.5wt%; Mo: 0.5-1.5wt%, and the remainder is Fe and unavoidable impurities, and the sum of the above components is 100%.

2. The high-toughness high-manganese steel flux-cored welding wire for laser cladding according to claim 1, characterized in that: The filling rate of the drug core (2) is 28-32 wt%.

3. The high-toughness high-manganese steel flux-cored welding wire for laser cladding according to claim 1, characterized in that: The diameter of the flux-cored welding wire is φ1.0mm-φ3.0mm.

4. The high-toughness high-manganese steel flux-cored welding wire for laser cladding according to claim 1, characterized in that: The core (2) has a Mn purity of ≥99% and a particle size of ≤0.3 mm; a C purity of ≥98% and a particle size of ≤0.3 mm; a Si purity of ≥98% and a particle size of ≤0.3 mm; a Mo purity of ≥99% and a particle size of ≤0.3 mm; and a Fe purity of ≥99% and a particle size of ≤0.3 mm.

5. The high-toughness high-manganese steel flux-cored welding wire for laser cladding according to claim 1, characterized in that: After the flux-cored welding wire is subjected to filler wire laser cladding, the composition of the wear-resistant high-manganese steel coating prepared is: Mn: 10-14wt%, C: 0.9-1.5wt%; Si: <1wt%; P: <0.05wt%; S: <0.05wt%; Mo: 0.15-0.45wt%; the balance is iron and inevitable impurities.

6. A method for preparing a high-toughness high-manganese steel flux-cored welding wire for laser cladding, comprising the flux-cored welding wire according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: S1. When the low carbon steel strip of the weld skin (1) is preferably made of Q195 carbon steel, the following raw material powders are weighed in mass percentage: Mn: 42-44%; C: 2-3.5%; Si: 1-2%; Mo: 0.5-1.5%, the remainder being Fe and unavoidable impurities, the sum of the above components being 100%; S2. When the low carbon steel strip of the weld skin (1) is preferably made of Q235 carbon steel, the following raw material powders are weighed in mass percentage: Mn: 40-43%; C: 3-4%; Si: 1-2%; Mo: 0.5-1.5%, the remainder being Fe and unavoidable impurities, the sum of the above components being 100%; S3, placing the raw material powder weighed in S1 in a vacuum heating furnace for heating to remove crystal water in the raw material; the dried raw material powder is fully mixed using a powder mixer to obtain a drug core (2); S4, using alcohol to remove grease from the surface of the carbon steel strip in S1, and wrapping the flux core (2) prepared in S2 in the steel strip through a flux-cored wire drawing device to form a process flux-cored wire; S5, performing a first drawing of the process flux-cored welding wire; S6. After the first drawing process is completed, the drawing is repeated multiple times, and the diameter of the flux-cored welding wire is reduced in sequence until a flux-cored welding wire with a diameter of 1.0-3.0 mm is obtained; S7, winding the workpieces with the required size in S6 in layers, so as to obtain the formed high manganese steel welding wire.

7. The preparation method according to claim 6, characterized in that: In S7, the laser cladding application of the prepared high manganese steel welding wire requires external application of protective gas.

8. The preparation method according to claim 7, characterized in that: The protective gas is high-purity argon.

9. The preparation method according to claim 8, characterized in that: The high manganese steel welding wire is suitable for the repair, surface modification and additive manufacturing of various crushers, high manganese rails, switches and bulldozers that are easily worn due to impact.

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