Wire for electric arc additive manufacturing of marine transmission component and additive manufacturing process of wire

Abstract

The invention relates to a wire material component for electric arc additive manufacturing of a marine transmission component and an additive manufacturing process of the wire material component, and belongs to the technical field of low-alloy high-strength steel wire material forming, and the wire material is composed of less than or equal to 0.04 wt% of C, 0.80-1.20 wt% of Mn, 0.20-0.40 wt% of Si, 0.90-1.20 wt% of Cr, 2.60-3.00 wt% of Ni, 0.20-0.40 wt% of Mo, 0.20-0.40 wt% of Cu, less than or equal to 0.010 wt% of S, less than or equal to 0.010 wt% of P and the balance Fe. According to the components and performance requirements of the marine transmission component, an alloy system and the content of all elements of the marine transmission component are determined, and the marine low-alloy high-strength steel transmission component meeting the use performance requirements is manufactured by adopting a gas metal arc welding deposition mode and optimizing deposition process parameters.

Description

Technical Field

[0001] The invention belongs to the technical field of low alloy high strength steel wire forming, and specifically relates to a wire for arc additive manufacturing of a ship's low alloy high strength steel transmission component and an additive manufacturing process thereof. Background Art

[0002] Low alloy high strength steel is widely used in automobile, bridge, pressure vessel, engineering machinery, shipbuilding and other fields due to its high strength, plasticity, low temperature toughness and good welding performance. The traditional manufacturing method of low alloy high strength steel components mainly adopts the methods of casting, forging, machining and other subtractive and equal material manufacturing, which not only has low production efficiency, high manufacturing cost and long production cycle, but also for some complex large and medium-sized metal components, its production is extremely difficult or even impossible to manufacture.

[0003] Arc additive manufacturing uses arc as heat source and wire as filling material, and realizes additive manufacturing of parts through the process of point-line-surface-body layer-by-layer accumulation in the molten pool. It is particularly suitable for the rapid manufacturing of large and medium-sized metal components due to its advantages of high deposition efficiency, low manufacturing cost and high material utilization rate. However, different steel components have different performance requirements, and low-alloy high-strength steel components manufactured by additive manufacturing with existing grades of welding wire cannot meet the performance requirements of marine transmission components. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a wire for arc additive manufacturing of ship low-alloy high-strength steel transmission components and an additive manufacturing process thereof, that is, according to the composition and performance requirements of the ship transmission components, the alloy system and the content of each element are determined, and the ship low-alloy high-strength steel transmission components that meet the performance requirements are manufactured by adopting a metal arc welding deposition method and optimizing the deposition process parameters.

[0005] The first technical problem solved by the present invention is to provide a low-alloy high-strength steel wire material composition for arc additive manufacturing of marine transmission components, which can achieve good toughness and corrosion resistance, and has low spatter, low slag, and suitable surface tension.

[0006] The second technical problem solved by the present invention is to provide an arc additive manufacturing process method capable of rapidly additively manufacturing ship-based low-alloy high-strength steel transmission components.

[0007] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is:

[0008] A wire for arc additive manufacturing of marine transmission components, characterized in that: the design composition (mass percentage wt.%) of the wire is as shown in Table 1. Design basis: Based on the chemical composition and performance requirements of marine transmission components (as shown in Tables 2 and 3), combined with the arc additive manufacturing process requirements of low spatter, low slag, and suitable surface tension, ultra-low carbon Ni-Mn-Cr-Mo-Cu is selected as the alloy system of marine low-alloy high-strength steel wire. The reasons are as follows: The mixed structure composed of bainite ferrite and granular bainite has good strength and toughness. Selecting ultra-low carbon can, on the one hand, reduce the formation of CO gas during deposition and reduce the spatter rate, and on the other hand, in the continuous cooling process, granular bainite structure can be obtained in a wide temperature range. Adding strengthening elements such as Mn, Cr, and Mo can, on the one hand, make up for the strength reduction caused by the reduction of carbon, and on the other hand, significantly reduce the phase transformation temperature of austenite, inhibit the formation of high-temperature proeutectoid ferrite structure, and promote the formation of granular bainite structure in the bainite transformation zone. The addition of appropriate amounts of Ni and Cu elements is mainly to improve the seawater corrosion resistance of low-alloy high-strength steel transmission components.

[0009] Table 1 Design range of wire composition for arc additive manufacturing of shipbuilding steel components (Wt%)

[0010]

[0011] Table 2 Chemical composition requirements for marine steel castings (Wt%)

[0012]

[0013] Table 3 Mechanical properties requirements of marine steel castings

[0014] The processing and manufacturing method of the above-mentioned wire material is:

[0015] According to the composition design range, high-purity iron, low-carbon ferromanganese, low-carbon ferrosilicon, pure carbon, metal molybdenum, metal chromium, metal nickel, and metal copper are selected as raw materials for smelting welding wire steel. A 200 kg vacuum induction furnace is used for smelting. After smelting, it is cast into a metal ingot with a diameter of 100 mm, and then the metal ingot is forged into a 50×50 mm square billet, and then rolled into a wire rod with a diameter of 8 mm by a rolling mill; the wire rod is annealed, rough drawn, fine drawn, and wound into a finished wire with a diameter of 1.2 mm.

[0016] The technical solution adopted by the present invention to solve the above second technical problem is:

[0017] Arc additive manufacturing is performed using gas metal arc welding (MIG) deposition.

[0018] Through experimental research and optimization, the following deposition process parameters are adopted: current 130-160A, voltage 21-25V, deposition speed 360-480mm / min, protective gas 95% Ar+5% CO2 mixed gas, flow rate 20L / min, low alloy high strength steel deposit can obtain a mixed structure composed of bainite ferrite and granular bainite, which can meet the performance requirements of marine low alloy high strength steel transmission components.

[0019] The beneficial effects of the present invention are:

[0020] 1. In the composition design of the present invention, the C content is reduced to an ultra-low carbon level, so that the strengthening method of the low-alloy high-strength steel transmission component does not rely on the solid solution strengthening of C, but by adding strengthening elements such as Mn, Cr, Mo, etc., the phase transformation temperature of austenite is reduced, the formation of high-temperature proeutectoid ferrite structure is inhibited, and the formation of granular bainite structure in the bainite transformation zone is promoted, so that the low-alloy high-strength steel deposit has good toughness and excellent crack resistance; and appropriate amounts of Ni and Cr elements are added to improve the seawater corrosion resistance of the steel component.

[0021] 2. The present invention adopts the metal arc gas shielded welding (MIG) deposition method, optimizes the deposition process parameters, and adopts 95% Ar + 5% CO2 mixed gas protection to achieve the performance requirements of arc additive manufacturing of ship-use low-alloy high-strength steel transmission components. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The metallographic structure of the wire obtained in Example 1 of the present invention;

[0023] Figure 2 This is the metallographic structure of the wire obtained in Example 2 of the present invention. DETAILED DESCRIPTION

[0024] In order to better explain the present invention and facilitate understanding, the technical solutions and effects of the present invention are described in detail below through specific implementation methods.

[0025] Embodiment 1:

[0026] The chemical composition (mass percentage) of the designed wire for arc additive manufacturing of marine low-alloy high-strength steel transmission components is: C 0.03%; Mn 1.1%; Si 0.34%; Cr 0.92%; Ni 2.78%; Mo 0.29%; Cu 0.32; S0.0022%; P 0.0029%, and the rest is Fe.

[0027] The forming processing technology and additive manufacturing process of the above-mentioned wire are:

[0028] High-purity iron, low-carbon ferromanganese, low-carbon ferrosilicon, pure carbon, metallic molybdenum, metallic nickel, and metallic copper are selected as raw materials for smelting welding wire steel in a 200 kg vacuum induction furnace. After smelting, it is cast into a metal ingot with a diameter of 100 mm, and then the metal ingot is forged into a 50×50 mm square billet, and then rolled into a wire rod with a diameter of 8 mm by a rolling mill; the wire rod is annealed, rough drawn, fine drawn, and wound into a finished wire with a diameter of 1.2 mm.

[0029] Using the low-alloy high-strength steel wire with the above composition, arc additive manufacturing was carried out by MIG deposition. The deposition process parameters were as follows: current 140A, voltage 24V, deposition speed 420mm / min, shielding gas 95% Ar + 5% CO2 mixed gas, flow rate 20L / min. The metallographic structure obtained was a mixed structure composed of ferrite and granular bainite (see Figure 1 The average tensile strength (UTS), yield strength (YS) and elongation (EL) of the deposited body are 736MPa, 542MPa and 23.3% respectively, and the UTS, YS and EL of the building direction are 753MPa, 553MPa and 22.5% respectively. The mechanical property requirements of Table 3 are met.

[0030] Embodiment 2:

[0031] The chemical composition (mass percentage) of the designed wire for arc additive manufacturing of marine low-alloy high-strength steel transmission components is: C 0.04%; Mn 0.98%; Si 0.25%; Cr 1.10%; Ni 2.96%; Mo 0.37%; Cu 0.25; S0.0036%; P 0.0047%, and the rest is Fe.

[0032] The forming processing technology and additive manufacturing process of the above-mentioned wire are:

[0033] High-purity iron, low-carbon ferromanganese, low-carbon ferrosilicon, pure carbon, metallic molybdenum, metallic nickel, and metallic copper are selected as raw materials for smelting welding wire steel in a 200 kg vacuum induction furnace. After smelting, it is cast into a metal ingot with a diameter of 100 mm, and then the metal ingot is forged into a 50×50 mm square billet, and then rolled into a wire rod with a diameter of 8 mm by a rolling mill; the wire rod is annealed, rough drawn, fine drawn, and wound into a finished wire with a diameter of 1.2 mm.

[0034] Using the low-alloy high-strength steel wire with the above composition, arc additive manufacturing was carried out by MIG deposition. The deposition process parameters were as follows: current 160A, voltage 25V, deposition speed 470mm / min, shielding gas was a mixed gas of 95% Ar+5% CO2, and the flow rate was 20L / min. The metallographic structure obtained was a mixed structure composed of ferrite and granular bainite (see Figure 2 The average tensile strength (UTS), yield strength (YS) and elongation (EL) of the deposited body are 746MPa, 557MPa and 22.5% respectively, and the UTS, YS and EL of the building direction are 759MPa, 568MPa and 21.4% respectively. The mechanical property requirements of Table 3 are met.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A wire material for arc additive manufacturing of marine transmission components, characterized in that: The composition of the wire material is: C≤0.04wt.%, Mn 0.80-1.20wt.%, Si 0.20-0.40wt.%, Cr 0.90-1.20wt.%, Ni 2.60-3.00wt.%, Mo 0.20-0.40wt.%, Cu 0.20-0.40wt.%, S≤0.010wt.%, P≤0.010wt.%, and Fe balance.

2. A method for preparing the wire material according to claim 1, characterized in that: The raw materials are selected according to the designed range of wire composition, and the welding wire steel is smelted in a vacuum induction furnace; after smelting, it is cast into a metal ingot with a diameter of 100 mm, and then the metal ingot is forged into a 50×50 mm square billet, and then rolled into a wire rod with a diameter of 8 mm by a rolling mill; the wire rod is processed into a finished wire with a diameter of 1.2 mm through annealing, rough drawing, fine drawing, and winding.

3. A method for additively manufacturing a marine transmission component using the wire material according to claim 1, characterized in that: Arc additive manufacturing is carried out using gas metal arc welding deposition.

4. The method for manufacturing a marine transmission component by wire additive manufacturing according to claim 3, characterized in that: The deposition process parameters are: current 130-160A, voltage 21-25V, deposition speed 360-480mm / min, protective gas 95% Ar+5% CO2 mixed gas, flow rate 20L / min.

5. A marine transmission component prepared by the method of claim 3 or 4, characterized in that: The marine transmission component is a mixed structure consisting of bainitic ferrite and granular bainite.

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