Precursor wire for electric arc additive manufacturing and preparation method and application of precursor wire

Abstract

The invention belongs to the technical field of welding materials, and particularly provides a precursor for electric arc additive manufacturing, which is characterized by comprising the following components in percentage by mass: 0.10-0.15% of C, 1.2-1.8% of Mn, 0.40-0.80% of Si, less than or equal to 0.003% of P, less than or equal to 0.003% of S, 1.45-1.85% of Cr, 0.50-0.90% of Mo, 0.50-0.70% of Ni, 0.5-0.8% of CeO2, 0.1-0.3% of Cu, 0.08-0.14% of Ti, 0.008-0.012% of B and the balance of iron and inevitable impurities. According to the precursor for electric arc additive manufacturing, a proper amount of Mn, Si, Cr, Mo, Ni, Cu and other alloys are added, and the alloys are transited to reactor melting metal in the printing process, so that the strength of the reactor melting metal is improved, and it is ensured that the tensile strength of the reactor melting metal is higher than 700 MPa. By adding Ti, B and CeO2 to refine grains, after a printed piece is subjected to heat treatment at 620 DEG C for 1 hour, the impact absorption energy at-45 DEG C can still be ensured to be 100 J or above, and the impurity content is low. The printing ink is used for printing of petroleum pipeline devices, molding is attractive, weld bead corrugations are fine, and printed metal has excellent hydrogen sulfide stress corrosion resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of welding materials, and particularly relates to a wire for arc additive manufacturing and a preparation method and application thereof. BACKGROUND

[0002] As core equipment in the links of oil exploitation, transportation and processing, the structural integrity and mechanical properties of oil pipeline devices are directly related to the production safety and operation efficiency of the oil industry. In practical applications, the structural parts of oil pipeline devices are mostly prepared by casting or forging process, but the complex structure of some positions makes the metal liquid flow uneven and the forming extremely difficult in the forging or casting process. At the same time, the traditional casting and forging process is limited by its own technical characteristics, and is prone to form quality defects such as shrinkage, porosity and inclusion in the structural parts, resulting in poor low-temperature impact toughness of the structural parts.

[0003] The arc additive manufacturing technology, with the technical advantages of layer-by-layer accumulation and near-net forming, is gradually applied to the manufacturing of oil pipeline device structural parts, can realize precise forming of complex structural parts, effectively shorten the manufacturing cycle, and has significant potential to improve the low-temperature impact toughness and corrosion resistance of the structural parts. The existing welding wire materials for arc additive manufacturing are mostly general-purpose materials, which cannot meet the needs of oil pipeline devices under specific conditions, so the development of suitable welding wire materials has become a technical problem to be solved in the current oil equipment manufacturing field. SUMMARY

[0004] The purpose of the present application is to overcome the problem that the welding wire materials for arc additive manufacturing in the prior art lack pertinence and cannot meet the needs of oil pipeline devices.

[0005] To this end, the present application provides a wire for arc additive manufacturing, which comprises, in mass percent, C 0.10-0.15%, Mn 1.2-1.8%, Si 0.40-0.80%, P≤0.003%, S≤0.003%, Cr 1.45-1.85%, Mo 0.50-0.90%, Ni 0.50-0.70%, CeO2 0.5-0.8%, Cu 0.1-0.3%, Ti 0.08-0.14%, B 0.008-0.012%, and the balance of iron and unavoidable impurities.

[0006] Specifically, the above-mentioned wire is coated with an electrolytic coating.

[0007] Specifically, the above-mentioned electrolytic coating is a copper-free electrolytic coating.

[0008] Specifically, the aforementioned precursor fiber, by mass percentage, includes 0.15% C, 1.2% Mn, 0.80% Si, 0.002% P, 0.0015% S, 1.85% Cr, 0.50% Mo, 0.50% Ni, 0.8% CeO2, 0.1% Cu, 0.14% Ti, 0.008% B, with the balance being iron and unavoidable impurities.

[0009] Specifically, the aforementioned precursor fiber, by mass percentage, includes 0.11% C, 1.4% Mn, 0.72% Si, 0.002% P, 0.0018% S, 1.65% Cr, 0.75% Mo, 0.62% Ni, 0.6% CeO2, 0.15% Cu, 0.12% Ti, 0.011% B, with the balance being iron and unavoidable impurities.

[0010] Specifically, the diameter of the precursor wire used in the above-mentioned electric arc additive manufacturing is 1.18-1.2 mm.

[0011] The present invention also provides a method for preparing the above-mentioned precursor wire for arc additive manufacturing, comprising the following steps: weighing each component according to the ratio, melting and forming a wire rod; drawing the wire rod to reduce its diameter; and drawing and annealing the wire rod after diameter reduction to obtain a finished welding wire.

[0012] Specifically, the above annealing process includes: heating to 350℃, holding for 100 minutes, then heating to 680℃ at a rate of 3-5℃ / min, holding for 400 minutes, then cooling to 480℃ at a rate of 5℃ / min, holding for 100 minutes, and finally slowly cooling to 120℃ before being removed from the furnace.

[0013] Specifically, inert gas protection is used during the above-mentioned wire rod annealing process.

[0014] The present invention relates to the application of the precursor fiber for arc additive manufacturing in the arc additive manufacturing of oil pipelines.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0016] The arc additive manufacturing precursor wire provided by this invention, by adding appropriate amounts of alloys such as Mn, Si, Cr, Mo, Ni, and Cu, allows the alloys to transition into the fused metal during the printing process, thereby improving the strength of the fused metal and ensuring a tensile strength higher than 700 MPa. By adding Ti, B, and CeO2 to refine the grain size, the printed part, after heat treatment at 620℃ for 1 hour, still maintains an impact absorption energy of over 100 J at -45℃, with low impurity content. When used for printing oil pipeline equipment, it produces aesthetically pleasing shapes with fine weld bead textures, and the printed metal exhibits excellent resistance to hydrogen sulfide stress corrosion. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Although representative embodiments of the present invention have been described in detail, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the embodiments, but should be defined by the appended claims and their equivalents.

[0018] This invention provides a precursor wire for arc additive manufacturing, comprising, by mass percentage: C 0.10–0.15%, Mn 1.2–1.8%, Si 0.40–0.80%, P ≤0.003%, S ≤0.003%, Cr 1.45–1.85%, Mo 0.50–0.90%, Ni 0.50–0.70%, CeO2 0.5–0.8%, Cu 0.1–0.3%, Ti 0.08–0.14%, B 0.008–0.012%, with the balance being iron and unavoidable impurities.

[0019] C is an interstitial solid solution strengthening element that can significantly improve strength. However, while increasing strength, C also reduces plasticity and toughness. Therefore, the C content is designed to be between 0.10% and 0.15%.

[0020] Si can improve the strength of steel, but when the Si content is too high, it tends to segregate at grain boundaries, which can promote the formation of intergranular cracks during stress corrosion. The Si content is designed to be between 0.40% and 0.80%.

[0021] Manganese (Mn) is a solid solution strengthening element that can improve strength and wear resistance. However, a high manganese content can increase strength but decrease corrosion resistance; therefore, the Mn content is designed to be between 1.2% and 1.8%.

[0022] Ti is a strong carbide element. Adding an appropriate amount of Ti can form fine TiC particles dispersed in the weld, which can improve the solubility of H in the weld and thus increase the critical value of hydrogen enrichment content that causes hydrogen-induced cracking. In addition, using Ti-B system can refine the grains, which can further increase the critical value of hydrogen enrichment content for hydrogen-induced cracking. Therefore, Ti-B system is beneficial for improving resistance to SSC.

[0023] CeO2 is a rare earth oxide, mainly used to refine grains and improve low-temperature impact toughness. It is mainly added in the form of cerium oxide, with a dosage range of 0.5% to 0.8% of the total weight. When the dosage is less than 0.5%, the effect is not obvious; when the dosage is greater than 0.8%, the printing results in poor molding.

[0024] The main function of Ni is to improve the low-temperature toughness of fused metals and lower the austenitic transformation temperature of steel. It also works synergistically with Cr to achieve a more significant corrosion resistance effect. In this invention, the dosage range is 0.5% to 0.7% of the total weight. A dosage less than 0.5% has little effect on improving impact toughness; a dosage greater than 0.7% leads to a decrease in the corrosion resistance of the fused metal.

[0025] The main function of Cr is to improve the strength and hardness of molten metal and enhance its corrosion resistance. In this invention, the dosage range is 1.45% to 1.8% of the total weight. When the dosage is less than 1.45%, the improvement effect is not obvious; when the dosage is greater than 1.85%, it leads to a decrease in strength and excessive hardness, and a deterioration in corrosion resistance.

[0026] The main function of Mo is to improve the low-temperature toughness, strength, and heat treatment performance of fused metals. In this invention, the dosage range is 0.5% to 0.9% of the total weight. When the dosage is less than 0.5%, the effect of improving the low-temperature impact toughness after heat treatment is not obvious; when the dosage is greater than 0.9%, it leads to excessively high strength of the fused metal.

[0027] Cu primarily reduces the critical nucleus size by lowering the austenite phase transformation temperature and increasing austenite stability. Simultaneously, it inhibits nucleus growth, ultimately refining the bainite laths and martensite substructure, thus improving microstructure uniformity. Cu also enhances the strength of the fused metal. The dosage range is 0.1% to 0.3% of the total weight. When the Cu content is below 0.1%, grain refinement is not significant; when the Cu content is above 0.3%, poor fused metal formation is likely to occur in this invention.

[0028] Sulfur and phosphorus (S and P) are harmful impurities. If the sulfur and phosphorus content in the molten metal is too high, it is easy to segregate during the crystallization of the molten pool, thereby increasing the hot cracking tendency of the weld metal. At the same time, it also reduces the impact toughness and corrosion resistance. Therefore, the content of S and P should be reduced as much as possible, with S ≤ 0.003% and P ≤ 0.003% in the raw wire.

[0029] Furthermore, the precursor fiber is coated with an electrolytic coating, preferably a copper-free electrolytic coating. The precursor fiber diameter is preferably 1.18-1.2 mm.

[0030] The present invention also provides a method for preparing the above-mentioned precursor wire for arc additive manufacturing, comprising the following steps: weighing each component according to the ratio, melting and forming a wire rod; drawing the wire rod to reduce its diameter; and drawing and annealing the wire rod after diameter reduction to obtain a finished welding wire.

[0031] The annealing process includes: heating to 350℃, holding for 100 minutes, then heating to 680℃ at a rate of 3-5℃ / min, holding for 400 minutes, then cooling to 480℃ at a rate of 5℃ / min, holding for 100 minutes, and finally being slowly cooled to 120℃ before being removed from the furnace.

[0032] Specifically, inert gas protection is used during the above-mentioned wire rod annealing process.

[0033] The following specific embodiments illustrate the effects of the arc additive manufacturing precursor fiber, its preparation method, and its application.

[0034] Example 1:

[0035] This embodiment provides a precursor wire for arc additive manufacturing, comprising, by mass percentage: C: 0.10%, Mn: 1.80%, Si: 0.40%, Cr: 1.45%, Mo: 0.90%, Ni: 0.70%, CeO2: 0.5%, Cu: 0.3%, Ti: 0.08%, B: 0.012%, with the balance being iron and unavoidable impurities, S: 0.0020%, and P: 0.0020%.

[0036] The above-mentioned precursor wire for arc additive manufacturing is prepared using the following steps:

[0037] Weigh each component according to the ratio, melt them to make wire rods, and remove rust from the surface of the wire rods.

[0038] After the wire rod is drawn and reduced in diameter using 8 sets of dies, the diameter of the welding wire is 1.85mm after rough drawing.

[0039] The wire rod after diameter reduction is subjected to wire drawing and annealing. The annealing process during the wire drawing is shown in Table 1.

[0040] The wire is coated with a copper-free electrolytic coating, and then the diameter is reduced to that of the finished welding wire before winding and packaging. The finished welding wire has a diameter of 1.18mm.

[0041] Example 2:

[0042] This embodiment provides a precursor wire for arc additive manufacturing, comprising, by mass percentage: C: 0.15%, Mn: 1.2%, Si: 0.80%, Cr: 1.85%, Mo: 0.50%, Ni: 0.50%, CeO2: 0.8%, Cu: 0.1%, Ti: 0.14%, B: 0.008%, with the balance being iron and unavoidable impurities, but S: 0.0015% and P: 0.0020%.

[0043] The above-mentioned precursor wire for arc additive manufacturing is prepared using the following steps:

[0044] Weigh each component according to the ratio, melt them to make wire rods, and remove rust from the surface of the wire rods.

[0045] After the wire rod is drawn and reduced in diameter using 8 sets of dies, the diameter of the welding wire is 1.85mm after rough drawing.

[0046] The wire rod after diameter reduction is subjected to wire drawing and annealing. The annealing process during the wire drawing is shown in Table 1.

[0047] The wire is coated with a copper-free electrolytic coating, and then the diameter is reduced to that of the finished welding wire before winding and packaging. The finished welding wire has a diameter of 1.18mm.

[0048] Example 3:

[0049] This embodiment provides a precursor wire for arc additive manufacturing, comprising, by mass percentage: C: 0.12%, Mn: 1.5%, Si: 0.80%, Cr: 1.55%, Mo: 0.70%, Ni: 0.60%, CeO2: 0.7%, Cu: 0.2%, Ti: 0.10%, B: 0.009%, with the balance being iron and unavoidable impurities, but S: 0.002% and P: 0.0025%.

[0050] The above-mentioned precursor wire for arc additive manufacturing is prepared using the following steps:

[0051] Weigh each component according to the ratio, melt them to make wire rods, and remove rust from the surface of the wire rods.

[0052] After the wire rod is drawn and reduced in diameter using 8 sets of dies, the diameter of the welding wire is 1.85mm after rough drawing.

[0053] The wire rod after diameter reduction is subjected to wire drawing and annealing. The annealing process during the wire drawing is shown in Table 1.

[0054] The wire is coated with a copper-free electrolytic coating, and then the diameter is reduced to that of the finished welding wire before winding and packaging. The finished welding wire has a diameter of 1.18mm.

[0055] Example 4:

[0056] This embodiment provides a precursor wire for arc additive manufacturing, comprising, by mass percentage: C: 0.12%, Mn: 1.2%, Si: 0.60%, Cr: 1.70%, Mo: 0.80%, Ni: 0.65%, CeO2: 0.7%, Cu: 0.3%, Ti: 0.11%, B: 0.010%, with the balance being iron and unavoidable impurities, but S: 0.002% and P: 0.002%.

[0057] The above-mentioned precursor wire for arc additive manufacturing is prepared using the following steps:

[0058] Weigh each component according to the ratio, melt them to make wire rods, and remove rust from the surface of the wire rods.

[0059] After the wire rod is drawn and reduced in diameter using 8 sets of dies, the diameter of the welding wire is 1.85mm after rough drawing.

[0060] The wire rod after diameter reduction is subjected to wire drawing and annealing. The annealing process during the wire drawing is shown in Table 1.

[0061] The wire is coated with a copper-free electrolytic coating, and then the diameter is reduced to that of the finished welding wire before winding and packaging. The finished welding wire has a diameter of 1.18mm.

[0062] Example 5:

[0063] This embodiment provides a precursor wire for arc additive manufacturing, comprising, by mass percentage: C: 0.11%, Mn: 1.4%, Si: 0.72%, Cr: 1.65%, Mo: 0.75%, Ni: 0.62%, CeO2: 0.6%, Cu: 0.15%, Ti: 0.12%, B: 0.011%, with the balance being iron and unavoidable impurities, but S: 0.0018% and P: 0.002%.

[0064] The above-mentioned precursor wire for arc additive manufacturing is prepared using the following steps:

[0065] Weigh each component according to the ratio, melt them to make wire rods, and remove rust from the surface of the wire rods.

[0066] After the wire rod is drawn and reduced in diameter using 8 sets of dies, the diameter of the welding wire is 1.85mm after rough drawing.

[0067] The wire rod after diameter reduction is subjected to wire drawing and annealing. The annealing process during the wire drawing is shown in Table 1.

[0068] The wire is coated with a copper-free electrolytic coating, and then the diameter is reduced to that of the finished welding wire before winding and packaging. The finished welding wire has a diameter of 1.18mm.

[0069] Table 1 Annealing process of solid welding wire in arc welding additive manufacturing technology

[0070]

[0071] Example 6:

[0072] The chemical composition of the fused metals prepared in Examples 1-5, tested according to standard requirements and industry-standard methods, is shown in Table 2; the mechanical properties are shown in Table 3; and the SSC test results are shown in Table 4.

[0073] Table 2: Chemical Composition of TMS3D70 Raw Material

[0074]

[0075] Table 3 Mechanical properties of molten metal

[0076]

[0077] Table 4 SSC Resistance Test of Molten Metal

[0078]

[0079] As shown in Tables 3-4, welding using the arc additive manufacturing precursor wire of this invention exhibits excellent welding process performance, including slag removal, porosity resistance, and spreading properties. The weld bead has fine and dense ripples, a beautiful shape, and good strength and high low-temperature impact toughness. Its tensile strength is greater than 720 MPa, and its impact energy at -45℃ is guaranteed to be above 100 J. It also has excellent resistance to hydrogen sulfide stress corrosion.

[0080] The above examples are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. All designs that are the same as or similar to the present invention are within the scope of protection of the present invention.

Claims

1. A precursor fiber for arc additive manufacturing, characterized in that: By mass percentage, it includes C 0.10–0.15%, Mn 1.2–1.8%, Si 0.40–0.80%, P ≤0.003%, S ≤0.003%, Cr 1.45–1.85%, Mo 0.50–0.90%, Ni 0.50–0.70%, CeO2 0.5–0.8%, Cu 0.1–0.3%, Ti 0.08–0.14%, B 0.008–0.012%, with the balance being iron and unavoidable impurities.

2. The precursor fiber for arc additive manufacturing as described in claim 1, characterized in that: The precursor fiber is coated with an electrolytic coating.

3. The precursor fiber for arc additive manufacturing as described in claim 2, characterized in that: The electrolytic coating is a copper-free electrolytic coating.

4. The precursor fiber for arc additive manufacturing as described in claim 1, characterized in that: By mass percentage, it includes 0.15% C, 1.2% Mn, 0.80% Si, 0.002% P, 0.0015% S, 1.85% Cr, 0.50% Mo, 0.50% Ni, 0.8% CeO2, 0.1% Cu, 0.14% Ti, 0.008% B, with the balance being iron and unavoidable impurities.

5. The precursor fiber for arc additive manufacturing as described in claim 1, characterized in that: By mass percentage, it includes 0.11% C, 1.4% Mn, 0.72% Si, 0.002% P, 0.0018% S, 1.65% Cr, 0.75% Mo, 0.62% Ni, 0.6% CeO2, 0.15% Cu, 0.12% Ti, 0.011% B, with the balance being iron and unavoidable impurities.

6. The precursor fiber for arc additive manufacturing as described in claim 1, characterized in that: The diameter of the precursor wire used in the arc additive manufacturing is 1.18-1.2 mm.

7. The method for preparing the precursor fiber for arc additive manufacturing as described in any one of claims 1-6, characterized in that, The process includes the following steps: weighing each component according to the ratio, melting and forming wire rod; drawing the wire rod to reduce its diameter; and drawing and annealing the wire rod to produce finished welding wire.

8. The method for preparing precursor wire for arc additive manufacturing as described in claim 7, characterized in that: The annealing process includes: heating to 350°C, holding for 100 min, then heating to 680°C at a rate of 3-5°C / min, holding for 400 min, then cooling to 480°C at a rate of 5°C / min, holding for 100 min, and finally slowly cooling to 120°C before being removed from the furnace.

9. The method for preparing precursor wire for arc additive manufacturing as described in claim 7, characterized in that: Inert gas protection is used during the wire rod annealing process.

10. The application of the arc additive manufacturing precursor wire as described in any one of claims 1-6 in the arc additive manufacturing of oil pipelines.

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