Stainless steel powder for molding and molded article

Abstract

To provide a stainless steel powder and a molded article for additive manufacturing, exhibiting superior corrosion resistance and reduced susceptibility to solidification cracking.SOLUTION: A stainless steel powder for additive manufacturing, comprising, in mass%, Cr: 16.0-18.0%, Ni: 12.0-15.0%, C: 0.03% or less, Si: 1.0% or less, Mn: 2.0% or less, Mo: 2.0-3.0%, and N: 400-2000 ppm, with the balance being Fe and inevitable impurities, wherein C+Si+Mn+N is more than 2.0% to 3.0%, Creq / Nieq is less than 1.5, P+S is 0.03% or less, O is 500 ppm or less, P is 0.045% or less, and S is 0.03% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to metal powders used in manufacturing methods involving rapid melting and rapid solidification processes, such as three-dimensional additive manufacturing, thermal spraying, laser coating, and build-up welding, and in particular to powders made of stainless steel that are suitable for additive manufacturing, and to objects manufactured using the rapid melting and rapid solidification process. [Background technology]

[0002] One stainless steel characterized by high corrosion resistance is SUS316L, a stainless steel bar specified in JIS (Japanese Industrial Standards) G 4303. SUS316L, which is made by solution treatment of ingot material, is known to be a highly corrosion-resistant stainless steel.

[0003] Therefore, in recent years, for stainless steels such as SUS316L, additive manufacturing (also known as 3D printing, three-dimensional stacking, additive manufacturing, etc.), which is a rapid melting and rapid solidification process, has been used to produce shaped objects. In additive manufacturing, a spread metal powder is irradiated with a laser beam or electron beam. The irradiation melts the metal particles in the powder. The particles then solidify. This melting and solidification process bonds the particles together. The irradiation is selectively performed on a portion of the metal powder. The unirradiated parts of the powder do not melt. A bonding layer is formed only in the irradiated parts.

[0004] A metal powder is then laid on top of the bonding layer. This metal powder is then irradiated with a laser beam or electron beam. The irradiation melts the metal particles. The metal then solidifies. This rapid melting and solidification bonds the particles together in the powder, forming a new bonding layer. This new bonding layer also bonds with the existing bonding layer.

[0005] By repeating the bonding by irradiation, an aggregate of bonding layers gradually grows. This growth results in a three-dimensional object. By using such an additive manufacturing method, it is possible to easily obtain objects with complex shapes. An example of an additive manufacturing method, which is a rapid melting and rapid solidification process, is disclosed in Patent Document 1.

[0006] In addition, a stainless steel for molding has been proposed that contains Fe as the main component and, by mass%, Cr: 10.5% to 20.0%, Ni: 1.0% to 15.0%, C+Si+Mn+N: 2.0% or less, and Mo+Cu+Nb: 5.0% or less, and that satisfies the following formulas (3) and (4) (see Patent Document 2). Cr eq / Ni eq ≧1.5 (3) P+S≦0.03 (4) This stainless steel is designed to be less susceptible to solidification cracking in molding processes that involve rapid melting and rapid solidification, by regulating the P and S contents. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 4661842 [Patent Document 2] Japanese Patent Publication No. 2022-23045 Summary of the Invention [Problem to be solved by the invention]

[0008] However, when additive manufacturing is performed using the components of SUS316L stainless steel, there is an issue of poor corrosion resistance in environments such as saltwater and seawater. The stainless steel disclosed in Patent Document 2 also has poor corrosion resistance.

[0009] Furthermore, stainless steel bodies produced by additive manufacturing are sometimes used in their rapidly solidified state without undergoing any special heat treatment after production. Therefore, when producing the above stainless steels by additive manufacturing, it has been difficult to maintain both solidification cracking resistance and high corrosion resistance.

[0010] Therefore, stainless steel powder with good corrosion resistance and low solidification cracking is required for additive manufacturing, as well as for other manufacturing methods involving rapid melting and rapid cooling / solidification processes, such as thermal spraying, laser coating, and cladding.

[0011] In light of the above background, the present inventors have developed a composition for the purpose of achieving both high corrosion resistance and solidification cracking resistance in a manufacturing method involving a rapid melting and rapid solidification process.

[0012] In other words, the object of the present invention is to provide a stainless steel powder and an additive manufacturing body that are highly corrosion resistant and less susceptible to solidification cracking, and are suitable for additive manufacturing in additive manufacturing methods involving a rapid melting, rapid cooling and solidification process. [Means for solving the problem]

[0013] As a result of extensive research, the inventors have found that the formation of ferrite and martensite phases is involved in the cause of the deterioration of corrosion resistance in the rapid melting and rapid solidification process. Then, focusing on the fact that the formation of austenite single phase is effective in improving corrosion resistance, the inventors have found that the formation of austenite single phase is effective in improving corrosion resistance. eq ) and nickel equivalent (Ni eq ) ratio (Cr eq / Ni eq ) and the amount of N added, it was found that corrosion resistance was improved.

[0014] In addition, Cr eq and Ni eq are the equivalents calculated by the following formulas: Cr eq = Cr + 1.4Mo + 1.5Si Ni eq = Ni + 0.3Mn + 22C + 14N It was also discovered that by specifying the total content of P and S and the total content of C, Si, Mn and N, respectively, solidification cracking and defects in the formed body can be suppressed. By specifying these, it was found that both high corrosion resistance and solidification cracking resistance can be obtained, which led to the present invention.

[0015] Therefore, the first means for solving the problems of the present invention is: By mass% Cr: 16.0~18.0%, Ni: 12.0-15.0% C: 0.03% or less, Si: 1.0% or less, Mn: 2.0% or less, Mo: 2.0-3.0% N: 400 to 2000 ppm and the balance being Fe and unavoidable impurities, C+Si+Mn+N: more than 2.0~3.0%, Cr eq / Ni eq : Less than 1.5 P+S: 0.03% or less, O: 500ppm or less, P: 0.045% or less, S: 0.03% or less, This is a stainless steel powder for additive manufacturing. However, Cr eq and Ni eq is calculated by substituting the mass% value for each component in the formula below. Cr eq =Cr+1.4Mo+1.5Si Ni eq =Ni+0.3Mn+22C+14N

[0016] The second means is a method for manufacturing a stainless steel powder for additive manufacturing according to the first means, further comprising: forming a powder having a particle diameter (D 50) is 15 to 100 μm, and the tap density (TD) of the powder is 3.0 to 6.0 Mg / m 3 And D 50 and the ratio of TD (D 50 / TD) is 2.5 to 20.0, that is, D 50 : 15~100μm, TD: 3.0~6.0Mg / m 3 , D 50 The stainless steel powder for additive manufacturing according to the first aspect satisfies all of the following conditions: / TD: 2.5 to 20.0.

[0017] The third method is In mass%, Cr: 16.0 to 18.0%, Ni: 12.0 to 15.0%, C: 0.03% or less, Si: 1.0% or less, Mn: 2.0% or less, Mo: 2.0 to 3.0%, N: 400 to 2000 ppm, and the balance being Fe and unavoidable impurities, C+Si+Mn+N: Over 2.0% to 3.0%, Cr eq / Ni eq The shaped body is made of stainless steel having the following: O: less than 1.5, P+S: 0.03% or less, O: 500 ppm or less, P: 0.045% or less, and S: 0.03% or less. However, Cr eq and Ni eq is calculated by substituting the mass% value for each component in the formula below. Cr eq =Cr+1.4Mo+1.5Si Ni eq =Ni+0.3Mn+22C+14N

[0018] The fourth aspect is a method for manufacturing a stainless steel product shape, in which a shaped body is obtained by three-dimensional additive manufacturing using the stainless steel powder according to either the first or second aspect. This method uses the stainless steel powder described in either the first or second means, and involves repeatedly irradiating a beam selectively to a portion of the spread metal powder, thereby rapidly melting and solidifying it to form a bonding layer, thereby obtaining a shaped body.

[0019] Another means is an additively manufactured body that is additively manufactured using either the first or second stainless steel powder for additive manufacturing. [Effects of the Invention]

[0020] By manufacturing the stainless steel powder for additive manufacturing according to the present invention using a process involving rapid melting, rapid cooling and solidification, i.e., additive manufacturing, additive manufacturing products can be obtained that are less susceptible to solidification cracking and have excellent corrosion resistance to seawater and other substances.

[0021] Also, the second method D 50 , T.D., D. 50 When additive manufacturing is performed using powder whose / TD satisfies the specified range, a molded body can be obtained that does not contain unmelted powder and does not contain inert gas, is less likely to develop voids, does not result in molding defects, and has excellent powder fluidity, resulting in a high-density molded body. DETAILED DESCRIPTION OF THE INVENTION

[0022] The stainless steel powder for additive manufacturing according to the present invention contains Cr as an essential additive component, and may contain Ni, Mo, Si, Mn, C, and N as optional additive components, with the remainder being Fe and unavoidable impurities. P, S, and O are unavoidable impurities.

[0023] Before describing the embodiments, the reasons for specifying the components of the stainless steel in the powder for layered manufacturing used in the layered manufacturing object of the present invention will be explained. Note that % of the chemical components is % by mass.

[0024] (Required additional ingredient) Cr: 16.0~18.0% Chromium (Cr) is a component that forms an oxide film on the surface of the compact. The Cr oxide film contributes to the corrosion resistance of the compact. From this perspective, the Cr content in stainless steel is set to 16.0% or more, and preferably 16.2% or more. On the other hand, Cr is also a ferrite-forming element. In stainless steels containing a large amount of Cr, the ferrite structure tends to remain, which reduces corrosion resistance. From these perspectives, the Cr content of the stainless steel used in the present application is set to 18.0% or less, and preferably 17.4% or less.

[0025] (optional added ingredients) Ni, Mo, Si, Mn, C, and N are optional components, but the following must be satisfied: C+Si+Mn+N: more than 2.0% to 3.0%.

[0026] Ni: 12.0 to 15.0% Nickel (Ni) is an austenite-forming element. In stainless steel containing a large amount of Ni, the austenite phase is easily formed, improving corrosion resistance. From this perspective, the Ni content of the stainless steel used in the present invention is set to 12.0% or more, and preferably 12.8% or more. On the other hand, if Ni is added in excess, its effects become saturated and costs increase. From this perspective, the Ni content added to the stainless steel used in the present invention is preferably set to 15.0% or less, and more preferably 14.2% or less.

[0027] C: 0.03% or less Carbon (C) is an austenite-forming element. A high C content contributes to the stabilization of the austenite phase. Excessive C content forms carbides with Cr, reducing intergranular corrosion resistance. Therefore, the C content added to the stainless steel used in the present invention is preferably 0.03% or less, and more preferably 0.02% or less.

[0028] Mn: 2.0% or less Manganese (Mn) is an austenite-forming element. A high Mn content contributes to the stabilization of the austenite phase. Even if excessive Mn is added, the effect saturates. Therefore, the Mn content added to the stainless steel used in the present invention is preferably 2.0% or less, and more preferably 1.8% or less.

[0029] Si: 1.0% or less, Silicon (Si) is a ferrite-forming element. Stainless steel with a low Si content can contribute to the toughness of the formed body. Addition of a large amount of Si inhibits the stabilization of the austenite phase. Therefore, the Si content added to the stainless steel used in the present invention is preferably 1.0% or less, and more preferably 0.8% or less.

[0030] Mo: 2.0-3.0% Molybdenum (Mo) has the function of repairing destroyed passive films in environments where corrosion progresses. From this perspective, the Mo content added to the stainless steel used in the present invention is preferably 2.0% or more, and more preferably 2.4% or more. On the other hand, Mo is a ferrite-forming element. Addition of a large amount of Mo inhibits the stabilization of the austenite phase. Therefore, the Mo content added to the stainless steel used in the present invention is preferably 3.0% or less, and more preferably 2.6% or less.

[0031] N: 400 to 2000 ppm Nitrogen (N) is an austenite-forming element. A high N content contributes to the stabilization of the austenite phase. It is also believed that forming nitrides at grain boundaries has the effect of suppressing molding cracks. From this perspective, the N content of the stainless steel used in the present invention is preferably 400 ppm or more, and more preferably 500 ppm or more. On the other hand, adding a large amount of N forms excess nitrides, which leads to a decrease in toughness, so the N content in the stainless steel used in the present invention is preferably 2000 ppm or less, and more preferably 1000 ppm or less. N can also be added by using nitrogen as the atomizing gas, or by using a high-nitrogen material such as chromium nitride as the melting raw material. However, since the nitrogen addition by the atomizing gas remains below 600 ppm, it is effective to use a high-nitrogen material as the melting raw material in order to add a higher nitrogen content.

[0032] C+Si+Mn+N: more than 2.0%~3.0%, From the viewpoint of improving the flow of the molten metal during molding and reducing the residual voids in the green body, the total content of C, Si, Mn, and N is more than 2.0%, and preferably 2.1% or more. On the other hand, if the total content of C, Si, Mn, and N is excessive, the toughness of the green body is impaired. From this viewpoint, the total content of C, Si, Mn, and N is 3.0% or less, and more preferably 2.5% or less.

[0033] In the present invention, the chromium equivalent (Cr eq ) is calculated using the following formula: Cr eq =Cr+1.4Mo+1.5Si Cr, Mo and Si are ferrite forming elements. Cr eq is an index that indicates the ease with which ferrite and martensite are formed in stainless steel.

[0034] In the present invention, the nickel equivalent (Ni eq ) is calculated using the following formula: Ni eq =Ni+0.3Mn+22C+14N Ni, Mn, C and N are austenite forming elements. eq is an index that indicates the ease with which austenite is formed in stainless steel.

[0035] Cr eq / Ni eq : Less than 1.5 In additive manufacturing processes using rapid melting, rapid solidification, and additive manufacturing, the chromium equivalent (Cr eq ) and nickel equivalent (Ni eq ) and the ratio (Cr eq / Ni eq ) is less than 1.5, i.e., Cr eq / Ni eq <1.5. If it exceeds 1.5, the corrosion resistance will decrease. From this point of view, Cr eq / Nieq The ratio of is less than 1.4, i.e., Cr eq / Ni eq It is preferable to make it <1.4. By the way, Cr eq If the amount is too small, the effect of adding Cr and Mo cannot be obtained, and the corrosion resistance decreases. eq Even if Cr is increased excessively, the effect will be saturated. eq / Ni eq The value of the ratio is preferably 0.5 or more, and more preferably 0.9 or more.

[0036] P: 0.045% or less, S: 0.03% or less, P+S: 0.03% or less, Phosphorus (P) and sulfur (S) are both unavoidable impurities. P and S tend to enter the δ phase of stainless steel. Therefore, stainless steel with two phases, the δ phase and the γ phase, has a large area ratio of grain boundaries within the steel, which means that P and S are dispersed. This P and S then make the steel more susceptible to cracking due to shrinkage during solidification.

[0037] Therefore, from the viewpoint of suppressing solidification cracking, the P content in the stainless steel used in the present invention is preferably 0.045% or less, and more preferably 0.03% or less.

[0038] Similarly, in the stainless steel used in the present invention, the S content is preferably 0.03% or less, and more preferably 0.02% or less.

[0039] From these viewpoints, it is preferable that the total content of P and S satisfies P + S ≦ 0.03%. In other words, in the stainless steel used in the present invention, the total content of P and S is preferably 0.03% or less, and more preferably 0.02% or less. Ideally, the P content may be zero, and the S content may also be zero.

[0040] O: 500ppm or less, Oxygen (O) is an unavoidable impurity. If the powder contains a large amount of O, gas is generated during molding, resulting in residual voids in the green body. Therefore, the O content of the stainless steel powder used in the present invention is preferably 500 ppm or less, and more preferably 300 ppm or less. Ideally, the O content may be zero.

[0041] [Powder preparation] There are various methods for producing stainless steel powder, but a suitable method is gas atomization. The raw materials are heated in a vacuum using high-frequency induction heating in an alumina crucible to form a molten alloy. The molten alloy is then dropped through a 5 mm diameter nozzle installed at the bottom of the crucible. High-pressure inert gas, such as nitrogen gas, is sprayed onto the molten metal, which atomizes and rapidly cools it, producing a large amount of fine powder. The resulting powder can then be classified to the desired size.

[0042] [Layered Manufacturing] The shaped body is obtained by subjecting the powder to a molding method involving a rapid melting, rapid cooling, and solidification process. Examples of such molding methods include three-dimensional additive manufacturing, thermal spraying, laser coating, and cladding. Typically, the molded body is formed by three-dimensional additive manufacturing.

[0043] In this 3D additive manufacturing method, a laser beam or electron beam is irradiated onto a spread-out layer of stainless steel powder. The irradiation causes the particles to heat up rapidly and melt. The particles then solidify rapidly. This melting and solidification process bonds the particles together. The irradiation is selectively performed on a portion of the stainless steel powder. The unirradiated portions of the stainless steel powder do not melt. A bonding layer is formed only in the irradiated portions.

[0044] Stainless steel powder is then spread over the bond layer. This stainless steel powder is then irradiated with a laser beam or electron beam. The irradiation causes the particles to rapidly melt. The particles then rapidly solidify. This melting and solidification process bonds the particles in the stainless steel powder together, forming a new bond layer. This new bond layer also bonds with the existing bond layer.

[0045] Repeated bonding by irradiation gradually grows the aggregate of bonding layers. This growth results in a three-dimensional object. This additive manufacturing method makes it easy to obtain objects with complex shapes.

[0046] Particle diameter D 50 is the particle size at the point where the cumulative curve is 50% when the total volume of the powder is 100% and the cumulative curve is calculated. Particle size can be measured using the Microtrac MT3000 laser diffraction / scattering particle size distribution analyzer manufactured by Nikkiso Co., Ltd. In this device, powder is poured into the cell of the device together with pure water, and the particle size is detected based on the light scattering information of the particles.

[0047] The particle diameter of the powder at 50% of the cumulative volume (D 50 ): 15~100μm Particle diameter D 50 The particle diameter D is preferably 15 to 100 μm. 50 This is because, when stainless steel powder having a particle diameter D in this range is used in additive manufacturing, a molded body can be obtained in which no unmelted powder remains and no inert gas is entrained. 50 It is particularly preferable that the thickness is 20 μm or more and 70 μm or less.

[0048] Tap density (TD): 3.0 to 6.0 Mg / m 3 , The tap density of the powder is 3.0 to 6.0 Mg / m 3 The tap density TD is measured in accordance with the provisions of JIS (Japanese Industrial Standards) Z 2512. 3If the TD is less than 3.0Mg / m, a sufficient amount of powder cannot be supplied when spreading the powder in the additive manufacturing process, resulting in voids in the molded body. 3 More than 4.0Mg / m is preferable. 3 On the other hand, TD is more preferably 6.0 Mg / m or more. 3 In these cases, the amount of powder may be excessive when spreading the powder, which may cause defective molding. Therefore, TD is set to 6.0Mg / m 3 Less than 5.0 Mg / m 3 The following is more preferred:

[0049] D 50 and the ratio of TD (D 50 / TD):2.5~20.0 Particle diameter D in powder 50 (μm) and tap density TD (Mg / m 3 ) and the ratio (D 50 / TD) is preferably 2.5 to 20.0. D 50 Powders with a ratio of D / TD of 2.5 or more have excellent fluidity, and therefore high-density compacts can be obtained from these powders. 50 The ratio / TD is more preferably 3 or more, and even more preferably 5 or more. D 50 In a compact obtained from a powder having a ratio of D / TD of 20 or less, unmelted powder is unlikely to remain inside. 50 It is more preferable that / TD is 18 or less, and it is particularly preferable that the ratio is 16 or less.

[0050] (Example) The effects of the present invention will be clarified below by examples, but the present invention should not be construed as being limited based on the descriptions of these examples.

[0051] [Powder production by gas atomization] A raw material consisting of the chemical components of Examples 1 to 8 and Comparative Examples 1 to 9 shown in Table 1, with the balance being Fe and unavoidable impurities, was gas atomized to obtain a stainless steel powder for additive manufacturing. First, the raw materials were heated in a vacuum in an alumina crucible by high-frequency induction heating to form a molten alloy. The molten alloy was then dropped from a 5 mm diameter nozzle installed at the bottom of the crucible, and high-pressure nitrogen gas was sprayed onto the molten metal, which atomized the molten metal and rapidly cooled it to obtain a large amount of fine powder. In Comparative Example 9, high-pressure argon gas was sprayed instead of nitrogen gas to obtain a fine powder. The obtained powder was classified so that the particle diameter was 63 μm or less. In addition, the lighter shaded areas in Table 1 indicate that the values ​​fall outside the range specified by the present invention.

[0052] [Table 1]

[0053] [Creating a model] This powder was classified to reduce the particle size of each particle to 63 μm or less. Using this powder as a raw material, additive manufacturing was carried out using a 3D additive manufacturing device (EOS-M290) to produce 10 mm square test pieces (10 × 10 × 10 mm). The manufacturing parameters used during manufacturing were GP1.

[0054] [Identification and quantification of crystalline phases] The obtained test specimen was cut in the center and the cross section was polished with a fine buff of 1000 grit or higher. The crystalline phase was identified by X-ray diffraction analysis (XRD) on a surface perpendicular to the forming direction. The amount of martensite was calculated from the peaks of austenite and martensite that were confirmed. The amount of martensite was calculated from the ratio of the main peak intensity ratio of martensite to the main peak intensity ratio of austenite. The results are shown in Table 2.

[0055] [Measurement of defect count] The 10mm square test pieces were cut in the center and the cross section polished with a fine buff of 1000 grit or higher. Cracks and residual voids were observed under an optical microscope on a surface perpendicular to the manufacturing direction. The number of defects was measured by counting cracks and residual voids in any 1mm x 1mm area. Here, cracks with a length of 30μm or more and residual voids with a diameter of 40μm or more were considered defects. The results are shown in Table 2.

[0056] [Relative density of the object] The density of the prepared 10 mm square test piece was calculated using the weight in air, the weight in water, and the density of water (Archimedes density measurement method). Meanwhile, the density of the powder was calculated by dry density measurement using the constant volume expansion method. The relative density of the laminate was calculated from the density of the test piece and the density of the powder.

[0057] The relative density of the shaped bodies in the examples was in the range of 99.6 to 99.9%. In the comparative examples, the components were outside the specified range, so the number of voids increased or cracks occurred, and the relative density was in the range of 97.5 to 97.8%.

[0058] [Tap Density] 120g of powder is poured into a container with a volume of 100cm 3 The mixture was packed into a cylinder. The tapping was carried out 200 times at a drop height of 10 mm, and the tap density was measured. The results are shown in Table 2.

[0059] [Salt spray test] Based on the standards set forth in JIS (Japanese Industrial Standards) Z 2371, the salt spray test was conducted under conditions of a spray chamber temperature of 35°C, a salt concentration of 5%, and a test time of 16 hours. The test specimens were φ12 x L21, and the entire surface was polished after processing. The results are shown in Table 2. The salt spray test results are expressed as follows: if rust was observed, it is considered a failure and marked with an "x", and if no rust was observed, it is considered a good failure and marked with a "o".

[0060] [Table 2]

[0061] In the additive manufacturing process using the stainless steel powders for additive manufacturing of Examples 1 to 8 of the present invention, good molded bodies were obtained, which had excellent resistance to solidification cracking and no defects were observed. In addition, the amount of martensite was small, and corrosion resistance to seawater and other elements was also confirmed.

[0062] The areas marked with light ink in the comparative examples in Table 1 deviate from the specifications of the present invention. The areas marked with light ink in Table 2 do not satisfy the evaluation items. Comparative Example 1 contains Ni and Cr eq / Ni eq The value is out of range, the amount of martensite is large, and the corrosion resistance is poor. Comparative Examples 2 and 3 are Cr eq / Ni eq The value is out of range, the amount of martensite is large, and the corrosion resistance is poor. Comparative Example 4 is Cr and Cr eq / Ni eq The value is outside the range, the amount of martensite is large, and the corrosion resistance is poor. In Comparative Example 5, the total amount of the components C+Si+Mn+N is too small, the amount of martensite is large, and the corrosion resistance is poor. Comparative Example 6 had excessive amounts of C, N, and C+Si+Mn+N, a large amount of martensite, poor corrosion resistance, and defects were observed, resulting in poor solidification cracking resistance. In Comparative Example 7, the P and the total value of P+S were excessive, defects were observed, and the solidification cracking resistance was poor. Comparative Example 8 has an excessively high O value, defects are observed, and solidification cracking resistance is poor. In Comparative Example 9, argon gas was sprayed when producing the powder by gas atomization, so the N value was excessive, defects were observed, and the solidification cracking resistance was poor. [Industrial Applicability]

[0063] The powder according to the present invention is also suitable for 3D printers in which the powder is ejected from a nozzle. The powder is also suitable for laser coating methods in which the powder is ejected from a nozzle.

Claims

1. By mass% Cr: 16.0-18.0%, Ni: 12.0-15.0%, C: 0.03% or less, Si: 1.0% or less, Mn: 2.0% or less, Mo: 2.0 to 3.0%, N: 400-2000ppm and the balance being Fe and unavoidable impurities, C+Si+Mn+N: more than 2.0% to 3.0%, Cr eq / Ni eq : Less than 1.5, P+S: 0.03% or less, O: 500 ppm or less, P: 0.045% or less, S: 0.03% or less, Stainless steel powder for additive manufacturing. However, Cr eq and Ni eq is calculated by substituting the mass% value for each component in the formula below. Cr eq =Cr+1.4Mo+1.5Si Ni eq =Ni+0.3Mn+22C+14N

2. The particle diameter of the powder at 50% cumulative volume (D 50 ): 15-100μm, Tap density (TD): 3.0 to 6.0 Mg / m 3 , D 50 and the ratio of TD (D 50 / TD): 2.5-20.0 The stainless steel powder for additive manufacturing according to claim 1, which satisfies the above.

3. By mass% Cr: 16.0-18.0%, Ni: 12.0-15.0%, C: 0.03% or less, Si: 1.0% or less, Mn: 2.0% or less, Mo: 2.0 to 3.0%, N: 400-2000ppm and the balance being Fe and unavoidable impurities, C+Si+Mn+N: more than 2.0% to 3.0%, Cr eq / Ni eq : Less than 1.5, P+S: 0.03% or less, O: 500 ppm or less, P: 0.045% or less, S: 0.03% or less, A shaped body made of stainless steel. However, Cr eq and Ni eq is calculated by substituting the mass% value for each component in the formula below. Cr eq =Cr+1.4Mo+1.5Si Ni eq =Ni+0.3Mn+22C+14N

4. A method for manufacturing a shaped body, comprising three-dimensionally additively manufacturing a shaped body using the stainless steel powder of claim 1 or 2.

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