Alloy composition and application thereof

Abstract

The invention discloses an alloy composition which comprises the following components in percentage by weight: 0.28 to 0.37 percent of C, 0.79 to 1.65 percent of Si, 0.62 to 1.22 percent of Mn, 2.47 to 5.18 percent of Cr, 1.37 to 3.42 percent of Mo, 1.05 to 2.53 percent of V, 1.05 to 1.75 percent of Co, 0.52 to 1.23 percent of W, 0.18 to 2.85 percent of Ni, 0.31 to 0.50 percent of Cu, less than or equal to 0.01 percent of P, less than or equal to 0.01 percent of S and the balance of Fe. According to the high-Mo alloy composition, in the SLM 3D printing process, cracking failure caused by laser thermal stress is reduced, high-C, high-hardness and high-wear-resistance alloy steel can be prepared, in addition, when the alloy composition is used for SLM 3D printing, a base plate does not need to be preheated to 200 DEG C or above, and the SLM technology of a domestic 3D printer can be met.

Description

Technical Field

[0001] The invention relates to an alloy composition and application thereof, in particular to a composition capable of preparing an alloy with high heat-resistance and wear resistance and application thereof. Background Art

[0002] Aluminum die casting is a pressure casting process that uses molds and pressure casting machinery to die-cast heated liquid aluminum or aluminum alloys to cast parts with shapes and sizes limited by the mold. Due to the good fluidity and plasticity of metal aluminum or aluminum alloys, aluminum die casting can produce a variety of complex shapes, and can also obtain high finish and precision, which greatly reduces the amount of mechanical processing and material casting allowance. Aluminum die castings are favored for their high production efficiency, low processing cost, high degree of mechanical automation, high dimensional accuracy, excellent surface quality and excellent overall mechanical properties. They are widely used in many industries such as automobile manufacturing, internal combustion engine production, motorcycle manufacturing, electric motor manufacturing, oil pump manufacturing, transmission machinery manufacturing, precision instruments, architectural decoration, and power equipment.

[0003] Die-casting molds, die-casting materials and die-casting equipment together constitute the three major elements of the die-casting process. As the application of aluminum die-casting becomes more and more extensive, higher requirements are also put forward for the comprehensive mechanical properties and life of die-casting molds. Among various molds, the working conditions of die-casting molds are more stringent, because pressure casting is to make molten metal fill the mold cavity under high pressure and high speed and die-cast it. During the working process, it repeatedly contacts with hot metal. Therefore, the die-casting mold is required to have high resistance to heat fatigue, thermal conductivity, wear resistance, corrosion resistance, impact toughness, red hardness, good demoulding properties, etc.

[0004] The die-casting mold industry in my country has developed rapidly, and the total output has increased significantly. The total output of domestic die-casting molds is second only to the United States, and has jumped to the second place in the world, becoming a veritable die-casting power. However, the international reputation of my country's die-casting molds is still ranked behind. Domestic die-casting molds still have many shortcomings in raw materials, processing technology, etc., which has become the main reason restricting the development of my country's die-casting mold industry. Taking aluminum die-casting molds as an example, in order to achieve higher heat and wear resistance, alloy powders with high Mo content are currently widely used as hot casting steel. For example, the American PM-9V (CPM-9V) steel has a C content of about 1.8wt%, a Mo content of about 1wt%, and a V content of about 9wt%, which can obtain a higher hardness, but the alloy has poor toughness and is more used as cold working die steel, and the heat treatment process is also significantly different from that of common die steel. 1.2367 steel has a higher Mo content and good hardness, but is prone to large plastic deformation.

[0005] DIEVAR from Swedish ASSAB is another high-quality mold steel on the market. It has high Mo and Cr content and is considered to be a rare alloy steel with high heat and wear resistance and high toughness. However, this alloy is used for casting rather than 3D printing.

[0006] EOS's MS1 alloy also has high hardness (50HRC) and toughness, but the alloy uses extremely high content of Ni (17-19%), Co (~9%), and Mo (~5%) elements, which is too expensive. And it requires a special hardening process, otherwise the hardness is only ~35HRC.

[0007] For general high-molybdenum materials, such as DIEVAR, PM-9V, 1.2367, and MS1, if SLM 3D printing is used, the substrate needs to be preheated to 500°C or even higher. If the temperature is not reached, excessive thermal stress will easily occur during the laser sintering process, resulting in poor stability and accuracy of the printed parts, and cracking. However, general domestic 3D printers can only be preheated to 200°C, so these high-Mo materials are difficult to process with domestic SLM 3D printing equipment.

[0008] Therefore, it is of great significance to find a high-quality alloy steel that can be 3D printed, especially a new hot working die steel, to achieve domestic substitution of 3D printing processes and equipment. Summary of the invention

[0009] The object of the present invention is to provide an alloy composition and application thereof to solve the problems raised in the above technical background.

[0010] The first aspect of the present application is to provide an alloy composition, in particular an alloy composition that can be SLM 3D printed, comprising, by weight:

[0011] C 0.28-0.37%,

[0012] Si 0.79-1.65%,

[0013] Mn 0.62-1.22%,

[0014] Cr 2.47–5.18%,

[0015] Mo 1.37-3.42%,

[0016] V 1.05-2.53%,

[0017] Co 1.05-1.75%,

[0018] W 0.52-1.23%,

[0019] Ni 0.18-2.85%,

[0020] Cu 0.31-0.50%,

[0021] P and S are both ≤0.01%, and the rest is Fe.

[0022] In a preferred embodiment, the C content in the alloy composition is preferably 0.3-0.35%, more preferably 0.32-0.34%, by weight.

[0023] In a preferred embodiment, the Si content in the alloy composition is preferably 0.8-1.6% by weight, more preferably 1-1.5%, and more preferably 1.2-1.4% by weight.

[0024] In a preferred embodiment, the Mn content in the alloy composition is preferably 0.65-1.2% by weight, more preferably 0.7-1%, and more preferably 0.8-0.95% by weight.

[0025] In a preferred embodiment, the Cr content in the alloy composition is preferably 2.5-5%, more preferably 2.8-4.5%, and more preferably 3-4%, by weight.

[0026] In a preferred embodiment, the alloy composition preferably has a Mo content of 1.4-3.2% by weight, more preferably 1.5-3% by weight, more preferably 1.8-2.8% by weight, and more preferably 2-2.5% by weight.

[0027] In a preferred embodiment, the V content in the alloy composition is preferably 1.1-2.5% by weight, more preferably 1.3-2.3%, and more preferably 1.5-2% by weight.

[0028] In a preferred embodiment, the Co content in the alloy composition is preferably 1.1-1.7% by weight, more preferably 1.2-1.5%, and more preferably 1.3-1.4% by weight.

[0029] In a preferred embodiment, the W content in the alloy composition is preferably 0.55-1.2% by weight, more preferably 0.6-1.1%, more preferably 0.7-1%, more preferably 0.8-0.9% by weight.

[0030] In a preferred embodiment, the Ni content in the alloy composition is preferably 0.2-2.8% by weight, more preferably 0.4-2.5%, more preferably 0.5-2.2%, more preferably 0.7-2%, more preferably 0.8-1.8%, more preferably 1-1.5%.

[0031] In a preferred embodiment, the average particle size of the alloy composition is preferably 1-80 μm, more preferably 5-70 μm, more preferably 10-60 μm, more preferably 15-55 μm, more preferably 20-50 μm.

[0032] The second aspect of the present invention is to provide an application of the alloy composition, preferably the alloy composition is used to prepare parts through an SLM (selective laser sintering) 3D printing process.

[0033] Preferably, the component is a mold, or a part of a mold (such as the surface layer of the mold, especially the layer in contact with the molding material). More preferably, it is one or more of a die-casting mold, an extrusion mold, a blow molding mold, an injection mold, and an injection mold (injection molding mold). For example, an aluminum die-casting mold, a copper-aluminum extrusion mold, a blow molding mold, and a high-glass fiber (fiberglass) plastic injection mold.

[0034] More preferably, the component is an aluminum die-casting mold, or a surface layer of an aluminum die-casting mold (especially a layer in contact with aluminum or aluminum alloy die-casting material).

[0035] Preferably, the alloy composition is used to prepare the R corner (such as rounded corner, clean corner) of the mold.

[0036] Preferably, the component is a knife or a part of a knife, for example, the part of the knife may be a blade, a cutting edge, in particular a cutting edge of a circular cutter.

[0037] In a preferred embodiment, the SLM 3D printing process includes:

[0038] Preheat the substrate or not,

[0039] The powder of the alloy composition is used to manufacture a component on a substrate through SLM 3D printing, and the manufactured component is removed from the substrate.

[0040] In a preferred embodiment, the SLM 3D printing may be to lay at least 2 layers of powder of the alloy composition, preferably at least 3 layers of powder of the alloy composition.

[0041] In a preferred embodiment, the SLM 3D printing process further comprises: performing a thermal stress elimination process on the components removed from the substrate.

[0042] Preferably, the treatment for eliminating thermal stress refers to heat treatment at 150-300°C, more preferably heat treatment at 200-250°C.

[0043] In a preferred embodiment, in the treatment for eliminating thermal stress, the heat treatment time is preferably 1-6 hours, more preferably 2-5 hours, and more preferably 3-4 hours.

[0044] In a preferred embodiment, the SLM 3D printing process further comprises: tempering the component removed from the substrate; or tempering the component after the treatment to eliminate thermal stress.

[0045] In a preferred embodiment, the substrate is preheated to ≤200°C, more preferably ≤195°C, more preferably 160-195°C, more preferably 170-185°C.

[0046] In a preferred embodiment, the temperature of the tempering treatment is preferably ≥350°C, more preferably ≥400°C, more preferably 400-800°C, more preferably 450-750°C, more preferably 500-70°C, more preferably 520-680°C, such as 550°C, 580°C, 600°C, 620°C, 650°C.

[0047] In a preferred embodiment, the tempering treatment time is preferably ≥ 3 hours.

[0048] In a preferred embodiment, the SLM 3D printing profile scanning diameter (effective spot diameter) is preferably 50-200 μm, more preferably 80-180 μm, and more preferably 100-150 μm.

[0049] In a preferred embodiment, the SLM 3D printing laser scanning speed is preferably 500-1500 mm / s, more preferably 800-1200 mm / s, more preferably 850-1000 mm / s, and more preferably 880-950 mm / s.

[0050] In a preferred embodiment, the SLM 3D printing laser power is preferably at least 50W, preferably at least 100W, more preferably 200-5000W, more preferably at least 300-3000W, more preferably 400-2000W.

[0051] In a preferred embodiment, the line spacing of the SLM 3D printing is 0.05-0.15 mm.

[0052] In a preferred embodiment, the SLM 3D printing powder layer thickness (each layer) is 0.01-0.2 mm, more preferably 0.02-0.15 mm, and more preferably 0.05-0.1 mm.

[0053] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0054] 1) The present invention provides a high-Mo alloy composition. During SLM 3D printing, the alloy composition does not require the substrate to be preheated to above 200°C, and can meet the SLM process of domestic 3D printers.

[0055] 2) The alloy composition provided by the present invention reduces cracking failure caused by laser thermal stress during SLM 3D printing.

[0056] 3) The alloy composition provided by the present invention can be used to prepare high-C, high-hardness and high-wear-resistant alloy steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is the friction coefficient of the product obtained in Example 1 of the present invention (tempered at 650° C.) at room temperature;

[0058] Figure 2 is the friction coefficient of the product obtained in Example 1 of the present invention (tempered at 650°C) at 400°C;

[0059] Figure 3 is the friction coefficient of the product obtained in Example 2 of the present invention (tempered at 580° C.) at room temperature;

[0060] Figure 4 is the friction coefficient of the product obtained in Example 2 of the present invention (tempered at 580°C) at 400°C;

[0061] Figure 5 is the friction coefficient of the existing alloy steel DEIVAR at room temperature;

[0062] Figure 6 is the friction coefficient of the existing alloy steel DEIVAR at 400°C;

[0063] Figure 7 It is the friction coefficient of existing alloy steel H13 steel (tempered at 650℃) at 400℃;

[0064] Figure 8 It is the friction coefficient of existing alloy steel 8407 (tempered at 650℃) at 400℃;

[0065] Fig. 9 These are photos of the products of Examples 1-3 of the present invention after being broken after testing their impact resistance and tensile properties (the dumbbell-shaped samples are samples for tensile property testing, and the rectangular samples are samples for impact resistance testing). DETAILED DESCRIPTION

[0066] The present invention provides an alloy composition, in particular, an alloy composition that can be used to manufacture a die-casting mold or a surface layer of a die-casting mold. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0067] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. The term "at least" in the present invention means greater than or equal to.

[0068] C content is the main factor affecting the microstructure. C can form carbides with other elements, thereby increasing the hardness of the alloy. However, an increase in C content will lead to a decrease in toughness, and insufficient C content will affect the hardness. In this patent, the C content is preferably 0.28-0.37%.

[0069] Si can refine the matrix structure, so an appropriate amount of Si can also improve hardness and wear resistance, but excessive silicon will reduce plasticity and toughness, and reduce processing performance. Therefore, in this patent, the Si content is preferably controlled at 0.79-1.65%.

[0070] Mn can increase carbon penetration, thereby improving the wear resistance and hardness of alloy steel. However, Mn will deteriorate the welding performance of steel and cause cracks, which is not conducive to additive manufacturing. In addition, brittleness, especially temper brittleness, will also increase significantly. In this patent, the Mn content is preferably controlled at 0.62-1.22%.

[0071] Cr can make carbon steel produce a passivation film of chromium iron oxide that is firmly bonded to the matrix structure in an oxidizing medium, thereby increasing wear resistance, corrosion resistance, etc., and Cr can reduce the stacking fault energy of the alloy. However, too high Cr content will lead to the precipitation of α-Cr. The Cr content of this patent is preferably controlled at 2.47-5.18%, so as to control Cr to exist in the matrix in a solid solution state.

[0072] Mo can improve the hardenability of steel, refine the structure, and enhance the strength and hardness of steel, but Mo will promote decarburization, reduce the austenite phase area, appear ferrite phase, reduce toughness, and reduce thermal conductivity. In this patent, the Mo content is 1.37-3.42%, and within this range, it is compounded with other elements to maintain the austenite structure.

[0073] V can form hard and stable VC carbide particles, strengthen grain boundaries and intergranular spaces, and can also be used as a grain refiner to reduce grain size, improve toughness and heat treatment properties. However, the formation of VC will reduce the alloy degree and thus the hardness. The V content in this patent is controlled at 1.05-2.53%.

[0074] Co can refine the grains and improve the thermal strength, but it is easy to precipitate brittle metal compounds, has a tendency to decarburize, and reduces the hardness. Moreover, as a precious metal, the cost of using Co is relatively high. The Co content in this patent is 1.05-1.75%.

[0075] W can form stable carbides, play a strengthening role in the microstructure, improve the hardness and wear resistance of steel, and improve the high temperature thermal stability of steel. Similar to Mo, W will also reduce the austenite phase area, W will also increase decarburization and reduce thermal conductivity. The W content in this patent is 0.52-1.23%.

[0076] Ni can be dissolved in Fe and form carbides with C to improve strength and fatigue resistance. However, Ni is an important strategic material and is relatively scarce. It should be used as little as possible. It is also prone to temper brittleness and poor hot hardness. Therefore, in this patent, the Ni content is 0.18-2.85%.

[0077] An appropriate amount of Cu can improve strength and hardness, but it is easy to produce hot brittleness during hot working, and the plasticity will be reduced. The Cu content in this patent is 0.31-0.50%.

[0078] Embodiment 1:

[0079] In this embodiment, the alloy composition components by weight are as follows:

[0080]

[0081] P and S are both <0.01wt%, and the rest is Fe.

[0082] SLM 3D printing was used. The SLM 3D printing equipment substrate was preheated to 180°C and 3D printing was performed on the substrate. The 3D printing parameters were as follows:

[0083] The effective spot size is 80 μm, the laser scanning speed is 850 mm / s, the laser power is 300 W, the line spacing is 0.08 mm, the layer thickness (each layer) is 0.05 mm, and a total of 2 layers are printed.

[0084] When 3D printing, a margin of at least 0.5 mm can be reserved, which will be removed during the subsequent machining process so that the final product meets the precise size requirements.

[0085] After 3D printing, the parts were heat treated at 250℃ for 3h to eliminate thermal stress, and then tempered at 650℃ for 5h.

[0086] Embodiment 2:

[0087] In this embodiment, the alloy composition components by weight are as follows:

[0088]

[0089] P and S are both <0.01wt%, and the rest is Fe.

[0090] SLM 3D printing was adopted, and the substrate of the SLM 3D printing equipment was preheated to 180° C., and 3D printing was performed on the substrate with reference to Example 1.

[0091] After 3D printing, the parts were heat treated at 250℃ for 3h to eliminate thermal stress, and then tempered at 580℃ for 5h.

[0092] Embodiment 3:

[0093] In this embodiment, the alloy composition components by weight are as follows:

[0094]

[0095]

[0096] P and S are both <0.01wt%, and the rest is Fe.

[0097] SLM 3D printing was adopted, and the substrate of the SLM 3D printing equipment was preheated to 180° C., and 3D printing was performed on the substrate with reference to Example 1.

[0098] After 3D printing, heat treatment was performed at 250°C for 3 hours to eliminate thermal stress, and then tempering treatment was performed at 550°C for 5 hours.

[0099] Reference Fig. 9 In Examples 1-3, each example is prepared according to GB / T228.1-2021 and GB / T229-2020 standards for tensile and impact tests. The equipment used is a WE-300 hydraulic universal testing machine, a ZES-(25-10) electronic extensometer and a 0-200 digital caliper.

[0100] In Examples 1-3, each example was prepared according to GB / T3850-2015 and GB / T22588-2008 standards, and density and thermal conductivity tests at 25°C and 400°C were performed. The equipment used was a Mazhihak MH-220S solid-liquid dual-purpose density tester (water temperature 24°C) and a NETZSCH LFA457 thermal conductivity meter (high-purity nitrogen, 50 ml / min).

[0101] Table 1, Performance Test of Examples 1-3 (20°C)

[0102]

[0103]

[0104] Reference Figure 1-Figure 4 Under the tempering condition of 580℃, the average friction coefficient tested at room temperature (25℃) is 0.3444, and the average friction coefficient tested at 400℃ is 0.1922; under the tempering condition of 680℃, the average friction coefficients tested at room temperature and 400℃ are 0.3174 and 0.3550 respectively. It can be seen that the present application has a lower friction coefficient at room temperature after tempering and has good wear resistance. The applicant also found that the tempering temperature has an effect on heat resistance and wear resistance. Under the tempering condition of 580℃, the heat resistance and wear resistance are particularly outstanding, with an average friction coefficient of only 0.1922, and has very good red hardness (high temperature wear resistance). Comparison Figure 5 and Figure 6 , the average friction coefficient of DIEVAR with excellent high-temperature wear resistance on the market at room temperature and 400°C is as high as 0.6388 and 0.5254 respectively. The alloy steel composition of the present invention adopts the SLM 3D printing process of the present application to obtain better wear resistance than DIEVAR, especially high-temperature wear resistance. Therefore, the alloy steel composition of the present application can be used as hot working die steel for making metal die-casting molds, especially aluminum die-casting molds.

[0105] Compared with other existing alloys used for 3D printing, refer to Figure 7 and Figure 8 The average friction coefficient of H13 steel at 400°C is 0.5158, and the average friction coefficient of 8047 steel at 400°C is 0.5053. It can be seen that the alloy steel in this application also has significantly higher heat and wear resistance than the alloys commonly used in 3D printing mold manufacturing.

[0106] Moreover, H13 steel and DISVAR steel cannot be SLM 3D printed on substrates preheated below 200°C, otherwise they will crack due to thermal stress, and the substrate temperature must be preheated to above 500°C. If H13 steel and DISVAR steel are forged, although the cracking problem can be solved, the heat and wear resistance will be greatly reduced by at least 25%.

[0107] It can be seen that the alloy steel composition of the present application can obtain good toughness through the SLM 3D printing process of the present application. However, in the case of 650°C tempering, the impact resistance and tensile strength are relatively lower than those of the samples tempered at 580°C and 550°C, but the difference in elastic modulus is not obvious.

[0108] Embodiment 4:

[0109] In this embodiment, the alloy composition components by weight are as follows:

[0110]

[0111]

[0112] Control P and S both < 0.01wt%,

[0113] The rest is Fe.

[0114] SLM 3D printing was used, the SLM 3D printing equipment substrate was preheated to 185°C, and the 3D printing parameters were as follows: effective spot size 100 μm, laser scanning speed 1000 mm / s, laser power 450 W, line spacing 0.08 mm, layer thickness (each layer) 0.05 mm, and a total of 2 layers were printed.

[0115] Temper at 650℃ for 6 hours and air cool.

[0116] Embodiment 5:

[0117] In this embodiment, the alloy composition components by weight are as follows:

[0118]

[0119] P and S are both <0.01wt%, and the rest is Fe.

[0120] SLM 3D printing was used, the SLM 3D printing equipment substrate was preheated to 175°C, and the 3D printing parameters were as follows: effective spot size 90 μm, laser scanning speed 900 mm / s, laser power 350 W, line spacing 0.08 mm, layer thickness (each layer) 0.05 mm, and a total of 2 layers were printed.

[0121] Temper at 580℃ for 6 hours and oil cool.

[0122] Embodiment 6:

[0123] In this embodiment, the alloy composition components by weight are as follows:

[0124]

[0125] P and S are both <0.01wt%, and the rest is Fe.

[0126] SLM 3D printing was used, the SLM 3D printing equipment substrate was preheated to 175°C, and the 3D printing parameters were as follows: effective spot size 80 μm, laser scanning speed 800 mm / s, laser power 400 W, line spacing 0.08 mm, layer thickness (each layer) 0.05 mm, and 2 layers were printed in total. Tempering at 580°C for 6 hours and oil cooling.

[0127] Table 2, Performance test results of Examples 4-6

[0128]

[0129]

[0130] The patented alloy composition of the present invention, the product obtained after 3D printing, has a slightly reduced hardness after tempering, but a greatly improved toughness, and the hardness before tempering is almost the same as the hardness of DISVAR before tempering, and the hardness after tempering is also almost the same as the hardness of DISVAR after tempering.

[0131] Compared with MS1, the hardness of the patented material before or after tempering can reach the hardness of MS1 after hardening treatment, which is much higher than the hardness of MS1 before hardening treatment.

[0132] Example 7

[0133] 3D printing was performed in the manner of Example 1 to form a 3D printing layer (0.05 mm) on the surface of Q235 low-carbon steel, which is common in China. During the SLM laser melting process, the low-carbon steel would dilute the C content in the components of the present invention. Without tempering, the hardness of the 3D printing layer was tested, and the hardness could still reach RHC 57.

[0134] The specific embodiments of the present invention are described in detail above, but they are only examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions made to the present invention are also within the scope of the present invention. Therefore, the equalization changes and modifications made without departing from the spirit and scope of the present invention should be included in the scope of the present invention.

Claims

1. An alloy composition, characterized in that By weight, including: C 0.28-0.37％， Si 0.79-1.65%, Mn 0.62-1.22%, Cr 2.47–5.18％， Mo 1.37-3.42%, V 1.05-2.53％， Co 1.05-1.75%, W 0.52-1.23％， Ni 0.18-2.85%, Cu 0.31-0.50%, P and S are both ≤ 0.01%, The rest is Fe.

2. The alloy composition according to claim 1, characterized in that In the alloy composition, the C content is preferably 0.3-0.35% by weight, more preferably 0.32-.034% by weight; In the alloy composition, the Si content is preferably 0.8-1.6% by weight, more preferably 1-1.5%, more preferably 1.2-1.4% by weight; In the alloy composition, the Mn content is preferably 0.65-1.2% by weight, more preferably 0.7-1%, and more preferably 0.8-0.95% by weight; In the alloy composition, the Cr content is preferably 2.5-5%, more preferably 2.8-4.5%, more preferably 3-4% by weight; In the alloy composition, the Mo content is preferably 1.4-3.2% by weight, more preferably 1.5-3%, more preferably 1.8-2.8%, more preferably 2-2.5% by weight; In the alloy composition, the V content is preferably 1.1-2.5% by weight, more preferably 1.3-2.3%, more preferably 1.5-2% by weight; In the alloy composition, the Co content is preferably 1.1-1.7% by weight, more preferably 1.2-1.5%, more preferably 1.3-1.4% by weight; In the alloy composition, the W content is preferably 0.55-1.2% by weight, more preferably 0.6-1.1%, more preferably 0.7-1%, more preferably 0.8-0.9% by weight; In the alloy composition, the Ni content is preferably 0.2-2.8% by weight, more preferably 0.4-2.5%, more preferably 0.5-2.2%, more preferably 0.7-2%, more preferably 0.8-1.8%, more preferably 1-1.5% by weight.

3. The alloy composition according to claim 1, characterized in that The average particle size of the alloy composition is preferably 1-80 μm, more preferably 5-70 μm, more preferably 10-60 μm, more preferably 15-55 μm, more preferably 20-50 μm.

4. Use of the alloy composition according to claim 1, characterized in that: The parts were produced using the SLM (Selective Laser Sintering) 3D printing process.

5. The use according to claim 4, characterized in that: The component is a mold, or a part of a mold.

6. The use according to claim 5, characterized in that: The component is one or more of a die-casting mold, an extrusion mold, a blow molding mold, an injection mold, and an ejection mold; preferably, part of the mold is a mold surface layer, especially a layer in contact with a molding material; more preferably, the component is an aluminum die-casting mold, or an aluminum die-casting mold surface layer; more preferably, the alloy composition is used to prepare the R angle of the mold.

7. The use according to claim 4, characterized in that: The component is a knife or a part of a knife. For example, the part of the knife can be a blade, a cutting edge, and in particular a cutting edge of a circular cutter.

8. The use according to claim 4, characterized in that: The SLM 3D printing process comprises: preheating or not preheating the substrate, preferably, the substrate is preheated to ≤200°C, more preferably ≤195°C, more preferably 160-195°C, more preferably 170-185°C; The powder of the alloy composition is used to manufacture parts on a substrate by SLM 3D printing. The fabricated component is removed from the substrate.

9. The use according to claim 8, characterized in that: The SLM 3D printing lays at least 2 layers of powder of the alloy composition, preferably at least 3 layers of powder of the alloy composition.

10. The use according to claim 8, characterized in that: The SLM 3D printing process further includes: removing the components from the substrate and performing a thermal stress elimination process; or Tempering of the parts removed from the substrate; or tempering of the parts after the treatment to eliminate thermal stress; Preferably, the treatment to eliminate thermal stress refers to heat treatment at 150-300°C, more preferably heat treatment at 200-250°C, and the heat treatment time is preferably 1-6 hours, more preferably 2-5 hours, more preferably 3-4 hours; Preferably, the temperature of the tempering treatment is preferably ≥350°C, more preferably ≥400°C, more preferably 400-800°C, more preferably 450-750°C, more preferably 500-70°C, more preferably 520-680°C, such as 550°C, 580°C, 600°C, 620°C, 650°C; the time of the tempering treatment is preferably ≥3 hours.

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