3D printing stainless steel material and preparation method thereof

Abstract

The invention discloses a 3D printing stainless steel material and a preparation method thereof, and relates to the technical field of 3D printing stainless steel materials. The 3D printing stainless steel material comprises the following components in percentage by mass: less than or equal to 0.01% of carbon, less than or equal to 0.02% of silicon, less than or equal to 0.50% of manganese, 14.00-16.00% of nickel, 15.00-18.00% of chromium, 2.50-3.00% of molybdenum, less than or equal to 0.30% of niobium, 0.03-0.06% of cerium, 0.10-0.40% of a graphene material, 0.08-0.10% of a graphene coated black phosphorus composite material and the balance of iron. By preparing the graphene-coated black phosphorus composite material and cooperating with the graphene material and cerium, the comprehensive performance of the 3D printing stainless steel material is effectively improved, and finally a 3D printing product obtains higher strength and longer service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 3D printing stainless steel material, in particular to a 3D printing stainless steel material and a preparation method thereof. BACKGROUND

[0002] 3D printing technology is an advanced manufacturing technology developed in recent years, which is a new manufacturing process based on three-dimensional model of parts, through continuous addition of materials, layer by layer accumulation, and then forming three-dimensional entity of parts. At present, 3D printing technology is mainly applied in mold production, and has been widely used in die casting and injection molding fields, such as mold inserts with conformal cooling channels, which can effectively shorten the cycle of injection molding of injection molding mold; the die casting mold with conformal cooling channels can reduce the spraying frequency of mold surface condensate in the die casting process, thereby prolonging the service life of the mold and maintaining the quality of the casting.

[0003] At present, the existing 3D printing stainless steel material has high oxygen content and impurities, which leads to poor performance of 3D printed products, such as defects in strength and density; in addition, the thermal conductivity of the existing 3D printing stainless steel material is lower than that of traditional materials, which leads to the fact that the product is not cooled in time during the 3D printing process, and micro-defects are easily generated in the product. These affect the service life of the mold manufactured by 3D printing to some extent, and further affect the cost and efficiency of actual production.

[0004] In summary, in order to solve the above problems, the present application provides a 3D printing stainless steel material which has the characteristics of high purity and appropriate thermal conductivity, can greatly enhance the service life of 3D printed products, and has important significance. SUMMARY

[0005] The present application aims to provide a 3D printing stainless steel material and a preparation method thereof to solve the problems raised in the background art.

[0006] In order to solve the above technical problems, the present application provides the following technical scheme: A 3D printing stainless steel material, comprising the following components, in terms of mass percentage, carbon ≤0.01%, silicon ≤0.02%, manganese ≤0.50%, nickel 14.00-16.00%, chromium 15.00-18.00%, molybdenum 2.50-3.00%, niobium ≤0.30%, cerium 0.03-0.06%, graphene material 0.10-0.40%, graphene coated black phosphorus composite material 0.08-0.10%, and the rest is iron.

[0007] Further, the graphene material is any one of graphene, nitrogen-doped graphene.

[0008] Further, the preparation method of the 3D printing stainless steel material comprises the following steps: Step one: carbon, silicon, manganese, nickel, chromium, molybdenum, and niobium are added to an induction furnace, and vacuum induction melting is performed to obtain alloy melt I; Step two: the alloy melt I is subjected to refining treatment to obtain alloy melt II; Step three: cerium, graphene material, and graphene-coated black phosphorus composite material are added to the alloy melt II, and stirring, mixing, and heat preservation are performed to obtain alloy melt III; Step four: the alloy melt III is subjected to vacuum atomization powdering and sieving to obtain the 3D printing stainless steel material.

[0009] Further, the parameters of the vacuum induction melting are: vacuum degree < 5 x 10 -2 Pa, melting temperature is 1500-1600℃, and heat preservation time is 10-30min.

[0010] Further, the refining treatment comprises two steps of desulfurization and dephosphorization, specifically: (1) Desulfurization: KR stirring method is used for desulfurization treatment of the alloy melt I, and slagging is performed before and after the addition of the desulfurizer to complete the desulfurization; (2) Dephosphorization: after desulfurization, the dephosphorizing agent is added to the alloy melt I, and then the alloy melt I is transferred into an LF furnace for dephosphorization and slagging to complete the dephosphorization.

[0011] Further, the desulfurizer is composed of calcium fluoride, calcium oxide, magnesium oxide, and aluminum oxide in a mass ratio of 1:1:(2-4):(4-6), and the addition amount is 1-2% of the mass of the alloy melt I.

[0012] The desulfurizer is composed of calcium fluoride, calcium oxide, magnesium oxide, and aluminum oxide in a mass ratio of 1:1:(2-4):(4-6), and the addition amount is 1-2% of the mass of the alloy melt I.

[0013] Further, the dephosphorizing agent is composed of calcium oxide and sodium salt in a mass ratio of (3-4):(1-2), and the addition amount is 0.5-1% of the mass of the alloy melt I.

[0014] Further, the sodium salt includes but is not limited to one or a combination of sodium chloride, sodium carbonate, and sodium nitrate.

[0015] Further, the parameters of the vacuum atomization powdering are: atomization pressure is 1-5MPa.

[0016] Further, the particle size of the 3D printing stainless steel material is D50 15-50μm.

[0017] Further, the preparation method of the graphene-coated black phosphorus composite material is: (1) Under argon protection, grind the black phosphorus to a particle size of D50 10-20 μm to obtain black phosphorus powder; (2) Under argon protection, add the black phosphorus powder and the cationic surfactant into isopropyl alcohol, and ultrasonically disperse for 30-60 min, and then filter, wash and dry to obtain pretreated black phosphorus powder; (3) Add the graphene material into isopropyl alcohol, and ultrasonically disperse for 30-60 min to obtain a graphene dispersion liquid of 2-3 mg / mL; (4) Under argon protection, add the pretreated black phosphorus powder into the graphene dispersion liquid, and stir to warm to 80-140 ℃, and reflux for 6-48 h, and then filter, wash and dry to obtain a graphene-coated black phosphorus composite; (5) Place the graphene-coated black phosphorus composite in a vacuum sintering furnace, and perform vacuum high-temperature annealing to obtain a graphene-coated black phosphorus composite material.

[0018] Further, the cationic surfactant is added in an amount of 0.1-1% of the mass of the black phosphorus powder.

[0019] Further, the cationic surfactant includes but is not limited to any one of cetyltrimethylammonium bromide, dodecyltrimethylammonium bromide, octyltrimethylammonium bromide and tetra-n-butylammonium bromide.

[0020] Further, the mass ratio of the graphene material and the pretreated black phosphorus powder is 1:(1-2).

[0021] Further, the parameters of the vacuum high-temperature annealing are: a vacuum degree <5×10 -2 Pa, an annealing temperature of 500-750 ℃, and an annealing time of 2-10 h.

[0022] Further, in the present application, the graphene material is any one of graphene and nitrogen-doped graphene.

[0023] Preferably, in the embodiments of the present application, the graphene material is nitrogen-doped graphene.

[0024] It can be known from the prior art that an appropriate amount of phosphorus can improve the structural stability of stainless steel, and has a certain improvement effect on the strength and corrosion resistance of stainless steel, and among the phosphorus, black phosphorus has more excellent thermal conductivity, and the improvement effect of introducing black phosphorus into 3D printing stainless steel material on the thermal conductivity of stainless steel is stronger. However, black phosphorus is extremely easy to be oxidized, and it is inevitable to combine with oxygen during 3D printing, which causes defects such as poor compactness in the interior of the 3D printed product, and further affects the performance of the 3D printed product. In addition, graphene material also has excellent thermal conductivity, and introducing it into 3D printing stainless steel material can not only improve the thermal conductivity of the 3D printed product, but also improve its related mechanical properties. Based on this, in the present application, black phosphorus is coated with graphene material to prevent black phosphorus from being oxidized, and then the performance of the 3D printed product is enhanced together with the graphene material. In order to enhance the coating effect of graphene material on black phosphorus, and at the same time avoid the agglomeration of graphene material, in the present application, cationic surfactant is used to pretreat black phosphorus powder, so that the surface of black phosphorus powder is coated with cationic surfactant. The electrostatic interaction between the large number of anion groups on the surface of graphene material and the cation groups on the pretreated black phosphorus powder enables the graphene material to uniformly form a coating on the surface of the black phosphorus powder, thereby obtaining a graphene-coated black phosphorus composite. Finally, the graphene-coated black phosphorus composite material is obtained by high-temperature sintering. The graphene-coated black phosphorus composite material can well improve the thermal conductivity and strength of the 3D printed stainless steel product, and the graphene material can improve the defect problems (such as brittleness) caused by black phosphorus to a certain extent, so the two can well improve the performance of the 3D printed stainless steel material, and thus obtain a 3D printed product with longer service life.

[0025] In the embodiment of the present application, nitrogen-doped graphene is preferably used as the graphene material. The reason is that nitrogen-doped graphene has better compatibility with alloy melt than ordinary graphene, and can be more easily dispersed in the alloy melt, thereby improving the performance of the prepared 3D printed stainless steel material, making the 3D printed product more dense and having higher mechanical properties.

[0026] In the present application, rare earth metal cerium and graphene material are further added to synergistically enhance and improve the 3D printed stainless steel material together with the graphene-coated black phosphorus composite material. The cerium can purify the alloy melt and improve the purity of the alloy melt, thereby making the 3D printed product more dense and obtaining higher strength and thermal conductivity. In addition, cerium can also lower the overall melting point of the alloy melt, thereby changing the original solidification system of the metal, making the subsequent vacuum atomization powdering easier, and effectively improving the efficiency of the vacuum atomization powdering. The graphene material can further improve the compactness and thermal conductivity of the 3D printed product.

[0027] Compared with the prior art, the present application has the following beneficial effects: (1) The stainless steel is subjected to desulfurization and dephosphorization refining treatment to improve its purity, so that the quality of the main raw material of the 3D printing stainless steel material is guaranteed, and the 3D printing stainless steel material with more excellent performance is prepared; (2) In the present application, the cationic surfactant is used to pretreat the black phosphorus powder, so that the surface of the black phosphorus powder is positively charged, and then the black phosphorus powder is combined with the negatively charged anion groups on the surface of the graphene material through electrostatic interaction, so that the graphene material uniformly coats the surface of the black phosphorus powder, and the graphene-coated black phosphorus composite material is obtained through vacuum annealing. The thermal conductivity and related properties of the 3D printing stainless steel material can be improved, and the density of the 3D printing product can be improved, and the 3D printing product with higher strength and service life can be obtained; (3) In the present application, the graphene material and cerium are further added to enhance and modify the 3D printing stainless steel material, further enhance the thermal conductivity and related properties, and obtain the 3D printing product with higher strength and service life; (4) In the present application, cerium, graphene material and graphene-coated black phosphorus composite material are added to the stainless steel, and the three work together to prepare a 3D printing stainless steel material with excellent performance. The 3D printing product processed by the 3D printing stainless steel material has excellent mechanical properties and thermal conductivity, and further exhibits longer service life.

[0028] In summary, by preparing the graphene-coated black phosphorus composite material and synergizing the graphene material and cerium, the comprehensive performance of the 3D printing stainless steel material is effectively improved, and finally the 3D printing product obtains higher strength and service life. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0030] It should be noted that the following parts are by weight, and the purchase of all raw materials involved in the present application has no special restrictions, including: Nitrogen-doped graphene, nitrogen content 3wt%, diameter 0.5-5μm, CAS number:7440-44-0, purchased from Xi'an Ruixi Biological Technology Co., Ltd.; Graphene, item number:1268698, thickness 0.55-3.74μm, diameter 0.5-3μm, CAS number:1032323-98-0, purchased from Shanghai Haohong Biological Medicine Technology Co., Ltd.; Cerium, purity 99.5%, item number: M24996, purchased from Shanghai Maier Biological Technology Co., Ltd. Black phosphorus, purity 99%, product code: B196539, purchased from Shanghai Aladdin Bio-Chem Technology Co., Ltd. The rest are commercially available.

[0031] Preparation: preparation of graphene-coated black phosphorus composite: 1. Graphene material selected graphene: (1) Under argon protection, grind black phosphorus to a particle size of D50 10~20 μm to obtain black phosphorus powder; (2) Under argon protection, add black phosphorus powder and cetyltrimethylammonium bromide to isopropyl alcohol, ultrasonic dispersion for 45 min, filter, wash and dry to obtain pretreated black phosphorus powder; wherein the amount of cetyltrimethylammonium bromide added is 0.6% of the mass of the black phosphorus powder; (3) Add graphene to isopropyl alcohol, ultrasonic dispersion for 45 min to obtain a graphene dispersion of 2.5 mg / mL; (4) Under argon protection, add pretreated black phosphorus powder to the graphene dispersion, stir and heat to 100°C, reflux for 36 h, filter, wash and dry to obtain graphene-coated black phosphorus composite; wherein the mass ratio of graphene material and pretreated black phosphorus powder is 1:1.5; (5) Place the graphene-coated black phosphorus composite in a vacuum sintering furnace and anneal under vacuum and high temperature to obtain graphene-coated black phosphorus composite material A; wherein the parameters for vacuum and high temperature annealing are: vacuum degree 3×10 -2 Pa, annealing temperature 650°C, annealing time 6 h.

[0032] 2. Graphene material selected nitrogen-doped graphene: (1) Under argon protection, grind black phosphorus to a particle size of D50 10~20 μm to obtain black phosphorus powder; (2) Under argon protection, add black phosphorus powder and cetyltrimethylammonium bromide to isopropyl alcohol, ultrasonic dispersion for 45 min, filter, wash and dry to obtain pretreated black phosphorus powder; wherein the amount of cetyltrimethylammonium bromide added is 0.6% of the mass of the black phosphorus powder; (3) Add nitrogen-doped graphene to isopropyl alcohol, ultrasonic dispersion for 45 min to obtain a graphene dispersion of 2.5 mg / mL; (4) Under argon protection, add pretreated black phosphorus powder to the graphene dispersion, stir and heat to 100°C, reflux for 36 h, filter, wash and dry to obtain graphene-coated black phosphorus composite; wherein the mass ratio of graphene material and pretreated black phosphorus powder is 1:1.5; (5) The graphene-coated black phosphorus composite is placed in a vacuum sintering furnace, vacuum high-temperature annealing is performed, and a graphene-coated black phosphorus composite material B is obtained; wherein the parameters of the vacuum high-temperature annealing are: a vacuum degree of 3x10 -2 Pa, an annealing temperature of 650 DEG C, and an annealing duration of 6h.

[0033] Example 1: A preparation method of a 3D printing stainless steel material: Step one: after the component raw materials are weighed according to the formula proportion, carbon, silicon, manganese, nickel, chromium, molybdenum, and niobium are added to an induction furnace, vacuum induction melting is performed, and an alloy melt I is obtained; The parameters of the vacuum induction melting are: a vacuum degree of 3x10 -2 Pa, a melting temperature of 1550 DEG C, and a holding duration of 20min; Step two: the alloy melt I is subjected to refining treatment, and an alloy melt II is obtained; (1) Desulfurization: the alloy melt I is subjected to desulfurization treatment by using a KR stirring method, slagging is performed before and after the addition of a desulfurizer, and desulfurization is completed; (2) Dephosphorization: after desulfurization, the alloy melt I is transferred into an LF furnace after a dephosphorizing agent is added, and dephosphorization and slagging are performed, and dephosphorization is completed; The desulfurizer is composed of calcium fluoride, calcium oxide, magnesium oxide, and aluminum oxide in a mass ratio of 1:1:3:5, and the addition amount is 1.5% of the mass of the alloy melt I.

[0034] The dephosphorizing agent is composed of calcium oxide and sodium salt in a mass ratio of 3.5:1.5, and the addition amount is 0.75% of the mass of the alloy melt I; Step three: cerium, graphene, and graphene-coated black phosphorus composite material A are added to the alloy melt II, stirring and mixing are performed, and holding is performed, and an alloy melt III is obtained; Step four: the alloy melt III is subjected to vacuum atomization powdering at an atomization pressure of 4MPa, and screening is performed, and a 3D printing stainless steel material with a D50 of 15-50um is obtained; The 3D printing stainless steel material comprises the following component raw materials: according to the mass percentage, carbon is ≤0.01%, silicon is ≤0.02%, manganese is ≤0.50%, nickel is 14.50%, chromium is 16.50%, molybdenum is 2.60%, niobium is ≤0.30%, cerium is 0.04%, graphene is 0.37%, graphene-coated black phosphorus composite material A is 0.09%, and the rest is iron.

[0035] Example 2: A preparation method of a 3D printing stainless steel material: Step one: after the component raw materials are weighed according to the formula proportion, carbon, silicon, manganese, nickel, chromium, molybdenum, and niobium are added to an induction furnace, vacuum induction melting is performed, and an alloy melt I is obtained; The parameters of vacuum induction melting are: vacuum degree is 3x10 -2 Pa, melting temperature is 1550℃, and holding time is 20min. Step two: refining treatment is performed on the alloy melt I to obtain alloy melt II. (1) Desulfurization: KR stirring method is used to perform desulfurization treatment on the alloy melt I, and slagging is required before and after the addition of desulfurizer, and desulfurization is completed. (2) Dephosphorization: after desulfurization, the dephosphorizing agent is added to the alloy melt I, and then it is transferred into the LF furnace for dephosphorization and slagging, and dephosphorization is completed. The desulfurizer is composed of calcium fluoride, calcium oxide, magnesium oxide and aluminum oxide in a mass ratio of 1:1:3:5, and the addition amount is 1.5% of the mass of the alloy melt I.

[0036] The dephosphorizing agent is composed of calcium oxide and sodium salt in a mass ratio of 3.5:1.5, and the addition amount is 0.75% of the mass of the alloy melt I. Step three: cerium, nitrogen-doped graphene, and graphene-coated black phosphorus composite material B are added to the alloy melt II, stirred and mixed, and held to obtain alloy melt III. Step four: the alloy melt III is atomized at a pressure of 4MPa to obtain a 3D printing stainless steel material with a D50 of 15-50μm. The 3D printing stainless steel material comprises the following component raw materials: carbon ≤0.01%, silicon ≤0.02%, manganese ≤0.50%, nickel 14.50%, chromium 16.50%, molybdenum 2.60%, niobium ≤0.30%, cerium 0.04%, nitrogen-doped graphene 0.37%, graphene-coated black phosphorus composite material B 0.09%, and the rest is iron.

[0037] Example 3: a preparation method of a 3D printing stainless steel material: Step one: after the component raw materials are weighed according to the formula proportion, carbon, silicon, manganese, nickel, chromium, molybdenum and niobium are added to an induction furnace, and vacuum induction melting is performed to obtain alloy melt I. The parameters of vacuum induction melting are: vacuum degree is 3x10 -2 Pa, melting temperature is 1550℃, and holding time is 20min. Step two: refining treatment is performed on the alloy melt I to obtain alloy melt II. (1) Desulfurization: KR stirring method is used to perform desulfurization treatment on the alloy melt I, and slagging is required before and after the addition of desulfurizer, and desulfurization is completed. (2) Dephosphorization: after desulfurization, the dephosphorizing agent is added to the alloy melt I, and then it is transferred into the LF furnace for dephosphorization and slagging, and dephosphorization is completed. The desulfurizing agent is composed of calcium fluoride, calcium oxide, magnesium oxide and aluminum oxide in a mass ratio of 1:1:3:5, and the added amount is 1.5% of the mass of the alloy melt I.

[0038] The dephosphorizing agent is composed of calcium oxide and sodium salt in a mass ratio of 3.5:1.5, and the added amount is 0.75% of the mass of the alloy melt I. Step three: cerium, graphene, and graphene-coated black phosphorus composite material B are added to the alloy melt II, stirred and mixed, and heat preserved to obtain alloy melt III. Step four: the alloy melt III is atomized at a pressure of 4 MPa to obtain a 3D printing stainless steel material with a D50 of 15-50 μm. The 3D printing stainless steel material comprises the following component raw materials: carbon ≤0.01%, silicon ≤0.02%, manganese ≤0.50%, nickel 14.50%, chromium 16.50%, molybdenum 2.60%, niobium ≤0.30%, cerium 0.04%, graphene 0.37%, graphene-coated black phosphorus composite material B 0.09%, and the rest is iron.

[0039] The following are control experiments based on Example 2, specifically shown in Comparative Examples 1-5: Comparative Example 1: Comparative Example 1 is based on Example 2, and the graphene-coated black phosphorus composite material B is not added, and the other processes remain unchanged, specifically: A preparation method of a 3D printing stainless steel material: Step one: after the component raw materials are weighed according to the formula ratio, carbon, silicon, manganese, nickel, chromium, molybdenum, and niobium are added to an induction furnace, and vacuum induction melting is performed to obtain an alloy melt I. The parameters of the vacuum induction melting are: vacuum degree is 3×10 -2 Pa, melting temperature is 1550℃, and heat preservation time is 20 min. Step two: the alloy melt I is refined to obtain an alloy melt II. (1) Desulfurization: KR stirring method is used for desulfurization treatment of the alloy melt I, and slagging is required before and after the addition of the desulfurizing agent to complete the desulfurization. (2) Dephosphorization: after desulfurization, the dephosphorizing agent is added to the alloy melt I, which is then transferred to an LF furnace for dephosphorization and slagging to complete the dephosphorization. The desulfurizing agent is composed of calcium fluoride, calcium oxide, magnesium oxide and aluminum oxide in a mass ratio of 1:1:3:5, and the added amount is 1.5% of the mass of the alloy melt I.

[0040] The dephosphorizing agent is composed of calcium oxide and sodium salt in a mass ratio of 3.5:1.5, and the added amount is 0.75% of the mass of the alloy melt I. Step three: cerium, nitrogen-doped graphene is added to the alloy melt II, stirred and mixed, and heat preserved to obtain alloy melt III; Step four: the alloy melt III is atomized at a pressure of 4 MPa to obtain a 3D printing stainless steel material with a D50 of 15-50 microns; The 3D printing stainless steel material comprises the following component raw materials: carbon ≤0.01%, silicon ≤0.02%, manganese ≤0.50%, nickel 14.50%, chromium 16.50%, molybdenum 2.60%, niobium ≤0.30%, cerium 0.04%, nitrogen-doped graphene 0.37%, and the rest is iron.

[0041] Comparative example 2 is based on example 2, with the following adjustments: no nitrogen-doped graphene is added, and the other processes remain unchanged, specifically: A method for preparing a 3D printing stainless steel material: Step one: after the component raw materials are weighed according to the formula, carbon, silicon, manganese, nickel, chromium, molybdenum, and niobium are added to an induction furnace, and vacuum induction melting is performed to obtain alloy melt I; The parameters for vacuum induction melting are: vacuum degree is 3x10 -2 Pa, melting temperature is 1550℃, and heat preservation time is 20 min; Step two: the alloy melt I is refined to obtain alloy melt II; (1) desulfurization: KR stirring method is used for desulfurization treatment of the alloy melt I, and slagging is required before and after the addition of the desulfurizer to complete the desulfurization; (2) dephosphorization: after desulfurization, the dephosphorizing agent is added to the alloy melt I, which is then transferred to the LF furnace for dephosphorization and slagging to complete the dephosphorization; The desulfurizer is composed of calcium fluoride, calcium oxide, magnesium oxide, and aluminum oxide in a mass ratio of 1:1:3:5, and the addition amount is 1.5% of the mass of the alloy melt I.

[0042] The dephosphorizing agent is composed of calcium oxide and sodium salt in a mass ratio of 3.5:1.5, and the addition amount is 0.75% of the mass of the alloy melt I. Step three: cerium, graphene-coated black phosphorus composite material B is added to the alloy melt II, stirred and mixed, and heat preserved to obtain alloy melt III; Step four: the alloy melt III is atomized at a pressure of 4 MPa to obtain a 3D printing stainless steel material with a D50 of 15-50 microns; The 3D printing stainless steel material comprises the following component raw materials: carbon ≤0.01%, silicon ≤0.02%, manganese ≤0.50%, nickel 14.50%, chromium 16.50%, molybdenum 2.60%, niobium ≤0.30%, cerium 0.04%, graphene-coated black phosphorus composite B 0.09%, and the rest is iron.

[0043] Comparative Example 3: Comparative Example 3 is based on Example 2, with the following adjustment: no cerium is added, and the other processes remain unchanged, specifically: A preparation method of a 3D printing stainless steel material: Step one: after the component raw materials are weighed according to the formula proportion, carbon, silicon, manganese, nickel, chromium, molybdenum and niobium are added to an induction furnace, and vacuum induction melting is performed to obtain alloy melt I; The parameters of vacuum induction melting are: vacuum degree is 3×10 -2 Pa, melting temperature is 1550℃, and holding time is 20 min; Step two: the alloy melt I is subjected to refining treatment to obtain alloy melt II; (1) desulfurization: the alloy melt I is subjected to desulfurization treatment by KR stirring method, and slagging is performed before and after the addition of the desulfurizer to complete the desulfurization; (2) dephosphorization: after desulfurization, the dephosphorizing agent is added to the alloy melt I, and then the alloy melt I is transferred into an LF furnace for dephosphorization and slagging to complete the dephosphorization; The desulfurizer is composed of calcium fluoride, calcium oxide, magnesium oxide and aluminum oxide in a mass ratio of 1:1:3:5, and the addition amount is 1.5% of the mass of the alloy melt I.

[0044] The dephosphorizing agent is composed of calcium oxide and sodium salt in a mass ratio of 3.5:1.5, and the addition amount is 0.75% of the mass of the alloy melt I. Step three: nitrogen-doped graphene and graphene-coated black phosphorus composite B are added to the alloy melt II, and stirring, mixing and holding are performed to obtain alloy melt III; Step four: the alloy melt III is subjected to vacuum atomization powdering at an atomization pressure of 4 MPa, and screening is performed to obtain a 3D printing stainless steel material with a D50 of 15-50 μm; The 3D printing stainless steel material comprises the following component raw materials: carbon ≤0.01%, silicon ≤0.02%, manganese ≤0.50%, nickel 14.50%, chromium 16.50%, molybdenum 2.60%, niobium ≤0.30%, nitrogen-doped graphene 0.37%, graphene-coated black phosphorus composite B 0.09%, and the rest is iron.

[0045] Comparative Example 4: Comparative Example 4 is based on Example 2, with the following adjustment: no refining treatment is performed, and the other processes remain unchanged, specifically: A preparation method of a 3D printing stainless steel material Step one: after the component raw materials are weighed according to the formula proportion, carbon, silicon, manganese, nickel, chromium, molybdenum and niobium are added into an induction furnace, vacuum induction melting is performed, and alloy melt I is obtained; The parameters of vacuum induction melting are as follows: the vacuum degree is 3x10 -2 Pa, the melting temperature is 1550℃, and the holding time is 20 min; Step two: cerium, nitrogen-doped graphene and graphene-coated black phosphorus composite material B are added into the alloy melt I, stirred and mixed, and held to obtain alloy melt III; Step three: the alloy melt III is vacuum atomized at an atomization pressure of 4 MPa to obtain a 3D printing stainless steel material with a D50 of 15-50 microns; The 3D printing stainless steel material comprises the following component raw materials: carbon ≤0.01%, silicon ≤0.02%, manganese ≤0.50%, nickel 14.50%, chromium 16.50%, molybdenum 2.60%, niobium ≤0.30%, cerium 0.04%, nitrogen-doped graphene 0.37%, graphene-coated black phosphorus composite material B 0.09%, and the rest is iron.

[0046] Comparative example 5: Comparative example 5 is based on example 2, and the adjustment is: only stainless steel is used to process a 3D printing stainless steel material, and other processes remain unchanged, specifically: A preparation method of a 3D printing stainless steel material Step one: after the component raw materials are weighed according to the formula proportion, carbon, silicon, manganese, nickel, chromium, molybdenum and niobium are added into an induction furnace, vacuum induction melting is performed, and alloy melt I is obtained; The parameters of vacuum induction melting are as follows: the vacuum degree is 3x10 -2 Pa, the melting temperature is 1550℃, and the holding time is 20 min; Step two: the alloy melt I is vacuum atomized at an atomization pressure of 4 MPa to obtain a 3D printing stainless steel material with a D50 of 15-50 microns; The 3D printing stainless steel material comprises the following component raw materials: carbon ≤0.01%, silicon ≤0.02%, manganese ≤0.50%, nickel 14.50%, chromium 16.50%, molybdenum 2.60%, niobium ≤0.30%, and the rest is iron.

[0047] Performance test: the 3D printing stainless steel materials prepared in the examples and comparative examples are printed into standard sample sizes (standard size length is 200 mm, cross section is rectangular cross section, length is 25 mm, and width is 5 mm) by using a 3D printing device, and thermal conductivity and tensile strength tests are performed, specifically as follows: (1) Thermal conductivity: test the thermal conductivity of the workpiece at room temperature, 100 DEG C, 200 DEG C, 400 DEG C; (2) Tensile strength: test the tensile strength by using a universal testing machine; The specific test results are shown in Table 1 below: Table 1

[0048] Conclusion: From the data in Table 1 above, it can be seen that comparative examples 1-3 show that nitrogen-doped graphene has better compatibility in the alloy, and the graphene-coated black phosphorus composite material B prepared by coating black phosphorus with nitrogen-doped graphene has a better reinforcing effect on 3D printed stainless steel material, and the two have a synergistic reinforcing effect; Comparative examples and comparative examples 1-5 show that under the synergistic effect of graphene-coated black phosphorus composite material B, nitrogen-doped graphene, cerium, and refining treatment, a high-performance 3D printed stainless steel material is prepared, and the 3D printed product processed therefrom has excellent thermal conductivity and tensile strength.

[0049] Finally, it should be noted that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A 3D printed stainless steel material, characterized in that: The alloy comprises the following components by mass percentage: carbon ≤0.01%, silicon ≤0.02%, manganese ≤0.50%, nickel 14.00-16.00%, chromium 15.00-18.00%, molybdenum 2.50-3.00%, niobium ≤0.30%, cerium 0.03-0.06%, graphene material 0.10-0.40%, graphene-coated black phosphorus composite material 0.08-0.10%, and the balance being iron.

2. The 3D printing stainless steel material according to claim 1, characterized in that: The preparation method of the graphene-coated black phosphorus composite material is as follows: (1) under argon protection, grinding black phosphorus to a particle size of D50 10-20 μm to obtain black phosphorus powder; (2) under argon protection, adding the black phosphorus powder and a cationic surfactant into isopropyl alcohol, ultrasonic dispersion for 30-60 min, and then filtering, washing and drying to obtain pretreated black phosphorus powder; (3) adding graphene material into isopropyl alcohol, ultrasonic dispersion for 30-60 min to obtain a graphene dispersion liquid with a concentration of 2-3 mg / mL; (4) under argon protection, adding the pretreated black phosphorus powder into the graphene dispersion liquid, stirring and heating to 80-140 ℃, refluxing for 6-48 h, and then filtering, washing and drying to obtain graphene-coated black phosphorus composite; (5) placing the graphene-coated black phosphorus composite in a vacuum sintering furnace, vacuum high-temperature annealing to obtain the graphene-coated black phosphorus composite material; wherein the cationic surfactant is added in an amount of 0.1-1% of the mass of the black phosphorus powder; the mass ratio of the graphene material to the pretreated black phosphorus powder is 1:(1-2).

3. The 3D printing stainless steel material according to claim 2, characterized in that: The parameters of the vacuum high-temperature annealing are: vacuum degree < 5*10 -2 Pa, annealing temperature is 500-750℃, and annealing duration is 2-10h.

4. The 3D printing stainless steel material according to claim 1, characterized in that: The graphene material is any one of graphene and nitrogen-doped graphene.

5. The 3D printing stainless steel material according to claim 4, characterized in that: The graphene material is nitrogen-doped graphene.

6. The method of claim 1-5, wherein the method further comprises: The method comprises the following steps: Step one: adding carbon, silicon, manganese, nickel, chromium, molybdenum and niobium into an induction furnace, vacuum induction melting to obtain alloy melt I; Step two: refining the alloy melt I to obtain alloy melt II; Step three: adding cerium, graphene material and graphene-coated black phosphorus composite material into the alloy melt II to obtain alloy melt III; Step four: vacuum atomization powdering the alloy melt III, and screening to obtain a 3D printing stainless steel material.

7. The method for preparing a 3D printed stainless steel material according to claim 6, characterized in that: The parameters of the vacuum induction melting are: vacuum degree < 5*10 -2 Pa, melting temperature is 1500~1600℃, and holding time is 10~30min; the parameters of the vacuum atomization powder preparation are: atomization pressure is 1~5MPa.

8. The method for preparing a 3D printed stainless steel material according to claim 6, characterized in that: The refining process comprises two steps of desulfurization and dephosphorization, specifically as follows: (1) desulfurization: using KR stirring method to desulfurize the alloy melt I, and performing slagging before and after adding a desulfurizing agent to complete the desulfurization; (2) dephosphorization: after desulfurization, adding a dephosphorizing agent into the alloy melt I, and then transferring it into an LF furnace to perform dephosphorization and slagging to complete the dephosphorization; wherein the desulfurizing agent is composed of calcium fluoride, calcium oxide, magnesium oxide and aluminum oxide in a mass ratio of 1:1:(2-4):(4-6), and is added in an amount of 1-2% of the mass of the alloy melt I; the dephosphorizing agent is composed of calcium oxide and sodium salt in a mass ratio of (3-4):(1-2), and is added in an amount of 0.5-1% of the mass of the alloy melt I.

9. A method for preparing a 3D printed stainless steel material according to claim 6, characterized in that: The particle size of the 3D printing stainless steel material is D50 15-50 μm.

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