WO2021215046A1

WO2021215046A1 - Molding powder or molding wire comprising stainless steel, or molded object being a laminate structure comprising stainless steel

Info

Publication number: WO2021215046A1
Application number: PCT/JP2020/047067
Authority: WO
Inventors: 健寛右原; 尚久高橋; 洋敬栗田; 洋之永本; 佳祐栗本
Original assignee: ヤマハ発動機株式会社
Priority date: 2020-04-24
Filing date: 2020-12-16
Publication date: 2021-10-28
Also published as: WO2021214958A1

Abstract

The present invention provides a molding powder or molding wire comprising stainless steel, or a molded object which is a laminate structure comprising stainless steel, wherein a molded object 1 having a complex shape can be molded simply while ensuring high temperature oxidation resistance of the molded object 1, which is a laminate structure.　The molding powder or molding wire comprising stainless steel according to the present invention contains 10.5 to 36 wt. % of Cr and contains 2 to 15 wt. % of Al, the remainder being Fe and unavoidable impurities, and is used in molding the molded object 1, which is a laminate structure. The molded object 1, which is a laminate body comprising stainless steel according to the present invention, is configured such that a plurality of laminate layers 4 are laminated in a first direction, at least some of the plurality of laminate layers 4 form gaps 3 capable of allowing a fluid to pass therethrough by means of a plurality of separating walls 2, and the fluid can pass through into an interior section via the gaps 3.

Description

Modeling powder or modeling wire made of stainless steel, or a modeled structure that is a laminated structure made of stainless steel

The present invention relates to a molding powder or a molding wire made of stainless steel used for modeling a shaped object which is a laminated structure made of metal, or a shaped object which is a laminated structure made of stainless steel.

Conventionally, there are modeling powders or modeling wires made of stainless steel used for modeling a modeled object which is a laminated structure made of stainless steel. For example, Patent Document 1 uses a three-dimensional additive manufacturing method, a thermal spraying method, a laser coating method, an overlay method, and other additive manufacturing methods that involve a rapid melting and quenching solidification process to form a modeled object that is a laminated structure. A modeling powder made of stainless steel is disclosed.

Japanese Unexamined Patent Publication No. 2019-19913

Molding powder or molding wire made of stainless steel is used in a laminated molding method that involves the process of rapidly melting with a laser beam, electron beam, etc., and then rapidly cooling and solidifying to form a model made of stainless steel. Be done. In these additive manufacturing methods, the modeling powder or the modeling wire is rapidly heated by being irradiated with a laser beam or an electron beam, and the metal particles of the modeling powder or the modeling wire are melted. The metal particles are then rapidly cooled and solidified. By repeating this melting and solidification, the metal particles are bonded to each other to form a modeled product which is a laminated structure.

With the additive manufacturing method as described above, a model with a complicated shape can be easily obtained. A powder for modeling or a wire for modeling made of stainless steel that can easily form a modeled object with a complicated shape while ensuring high temperature oxidation resistance of the modeled object that is a laminated structure formed by the additive manufacturing method. It has been demanded.

The present invention is a molding powder or a molding wire made of stainless steel, or stainless steel, which can easily form a shaped object having a complicated shape while ensuring high temperature oxidation resistance of the shaped object which is a laminated structure. It is an object of the present invention to provide a modeled object which is a laminated structure composed of.

The inventors of the present application are studying a modeled object which is a laminated structure made of stainless steel using a modeling powder made of stainless steel or a modeling wire having both high temperature oxidation resistance and ease of modeling. , I was able to obtain new findings.
It was found that in order to ensure the high temperature oxidation resistance of the modeled product, which is a laminated structure made of stainless steel, it is sufficient that the modeling powder or the modeling wire made of stainless steel contains a relatively large amount of Cr. .. If the molding powder made of stainless steel or the molding wire contains a relatively large amount of Cr, the high temperature oxidation resistance of the shaped product, which is a laminated structure made of stainless steel, can be improved. Further, if the modeling powder made of stainless steel or the modeling wire contains a relatively large amount of Cr, the coefficient of thermal expansion of the modeled object, which is a laminated structure made of stainless steel, becomes small, and the modeled object can be easily modeled with dimensional accuracy. Will increase. Further, if the molding powder made of stainless steel or the molding wire contains a relatively large amount of Cr, it is possible to reduce the thermal stress of the modeled product which is a laminated structure made of stainless steel at high temperature and increase the thermal fatigue strength. can.
Here, as a modeled object having a complicated shape, a laminated structure in which a plurality of structure layers having a gap through which a fluid can pass is laminated, and the fluid can be passed through the laminated structure as a whole using the gap. There is a model that can be done. It has been found that if the modeling powder or the modeling wire is difficult to melt in the melting process of the additive manufacturing method, it is difficult to easily form a modeled object having such a complicated shape. It was also found that a modeled object having a complicated shape is required to be easily modeled rather than ensuring strength.
Therefore, the present inventors simply make stainless steel while ensuring high temperature oxidation resistance of the model, which is a laminated structure made of stainless steel, when modeling a model having such a complicated shape. We examined the technical concept for modeling a modeled object that is a laminated structure.
The technical idea is to ensure the high temperature oxidation resistance of the modeled product, which is a laminated structure made of stainless steel, by including a component that can ensure high temperature oxidation resistance in the molding powder or the modeling wire made of stainless steel. At the same time, the technical idea is to simplify the modeling of a modeled object, which is a laminated structure made of stainless steel, by including a component having a low melting point in a modeling powder or a modeling wire made of stainless steel.
The inventors of the present application not only contain Cr that can ensure high-temperature oxidation resistance in a molding powder or a molding wire made of stainless steel, or a molded product that is a laminated structure made of stainless steel, but also have a melting point higher than that of Cr. It has been found that the above object can be achieved if it is configured to contain a low amount of Al.

(1) The molding powder or molding wire made of stainless steel of the present invention contains 22 to 36% by weight of Cr and 3 to 15% by weight of Al, and the balance is Fe and unavoidable impurities. It is characterized in that it is used for modeling a modeled object which is a laminated structure composed of a plurality of structural layers laminated. The modeled object has the laminated structure in which at least a part of the plurality of structure layers forms a gap through which the fluid can pass, and the fluid can pass through the gap inside. The body.
(2) Preferably, the molding powder or the molding wire made of the stainless steel of the present invention contains 25 to 26% by weight of Cr.
(3) Preferably, the modeling powder or modeling wire made of stainless steel of the present invention contains 2.5 to 3.5% by weight or 4.5 to 5.5% by weight of Al.

(16) The modeling powder or modeling wire made of stainless steel of the present invention contains 22 to 36% by weight of Cr and 2 to 15% by weight of Al, and the balance is Fe and unavoidable impurities. It is characterized in that it is used for modeling a modeled object by a laminated modeling method involving a rapid melting and quenching solidification process.
According to another aspect of the present invention, the modeling powder or modeling wire made of stainless steel of the present invention preferably has the above-mentioned configuration (2) or (3) in addition to the above-mentioned configuration (16). ..

According to these configurations, since the modeling powder or the modeling wire made of stainless steel contains a relatively large amount of Cr, the high temperature oxidation resistance of the model formed from the modeling powder or the modeling wire is improved. Further, since the modeling powder or the modeling wire made of stainless steel contains a relatively large amount of Cr, the coefficient of thermal expansion of the modeled object is reduced, the modeled object is easily modeled, and the dimensional accuracy is improved. Further, since the modeling powder or the modeling wire made of stainless steel contains a relatively large amount of Cr, it is possible to reduce the thermal stress of the modeled object at a high temperature and increase the thermal fatigue strength. Then, Al is contained in the modeling powder or the modeling wire made of stainless steel. Since Al has a low melting point, the modeling powder or the modeling wire is easily melted in the melting step in the laminated modeling method involving the rapid melting and quenching solidification process, and the modeled object can be easily modeled. In addition, Al can maintain the high temperature oxidation resistance of the modeled object. Here, when Al is contained in an amount of 3% by weight or more, a stable Al oxide film can be formed and the Cr oxide film can be protected. Further, by containing a large amount of Al, it is possible to prevent all Al from being oxidized and to suppress deterioration of the modeled object due to oxidation of Fe contained in the modeled object. On the other hand, if the amount of Al is too large, the coefficient of thermal expansion of the modeled object becomes high, and the thermal stress of the modeled object at a high temperature becomes high. However, when Al is contained in an amount of 15% by weight or less, preferably 8% by weight or less, the coefficient of thermal expansion of the modeled object can be suppressed and the thermal stress of the modeled object at a high temperature can be reduced. As a result, a modeled object having a complicated shape is modeled using the modeling powder or the modeling wire of the present invention. A model having a complicated shape is, for example, a laminated structure in which a plurality of structure layers are laminated, and at least a part of the plurality of structure layers forms a gap through which a fluid can pass. It is a laminated structure configured to allow fluid to pass through inside using gaps. Therefore, according to the present invention, it is possible to easily form a modeled object having a complicated shape while ensuring high temperature oxidation resistance of the modeled object of the laminated structure.

According to another aspect of the present invention, the molding powder or the molding wire made of the stainless steel of the present invention preferably has the following constitution in addition to the above configurations (1) to (3).
(4) The modeling powder or modeling wire made of stainless steel of the present invention contains 0.1 to 1.5% by weight of Si.

According to this configuration, the diameter of the molding powder particles made of stainless steel or the molding wire can be made relatively small. By reducing the diameter of the modeling powder particles or the modeling wire made of stainless steel, the modeling powder or the modeling wire is easily melted in the melting process, and the modeled object can be easily modeled. As a result, the modeled object can be modeled more easily while ensuring the high temperature oxidation resistance of the modeled object.

According to another aspect of the present invention, the modeling powder or modeling wire made of stainless steel of the present invention preferably has the following configuration in addition to the configuration of (4) above.
(5) In the molding powder or molding wire made of stainless steel of the present invention, C is 0.015% by weight or less, S is 0.015% by weight or less, Mn is 0.1 to 2.0% by weight, and N. Is contained in an amount of 0.040% by weight or less.
(6) Preferably, the modeling powder or modeling wire made of stainless steel of the present invention contains C in an amount of 0.015% by weight or less, S in an amount of 0.01% by weight or less, and Si in an amount of 0.4 to 0.8% by weight. %, Mn is contained in an amount of 0.30 to 0.50% by weight, and N is contained in an amount of 0.020% by weight or less.
(7) Preferably, the modeling powder or modeling wire made of stainless steel of the present invention contains C of 0.008% by weight or less, S of 0.002% by weight or less, Si of 0.15% by weight or less, and Mn. Is contained in an amount of 0.30% by weight or less and N is contained in an amount of 0.015% by weight or less.

According to these configurations, since C is contained in a relatively small amount, the oxidation resistance of stainless steel is improved, and carbides and nitrides of Cr are less likely to be generated during molding, so that molding can be performed easily. Further, since S is contained in a relatively small amount, the oxidation resistance of the stainless steel is improved, and carbides and nitrides of Cr are less likely to be generated during molding, so that molding can be easily performed. Further, if the amount of Si is too large, the peeling resistance of the oxidation scale is lowered, but if the amount of Si is too small, the high temperature oxidation resistance of the modeled product is lowered. An oxide film can be formed to slow down the oxidation rate of the modeled object. Further, if the amount of Mn is too large, the oxidation rate of the modeled product is increased, so that the oxidation resistance and corrosion resistance of the modeled product deteriorate. However, since Mn is contained in a relatively small amount, the resistance of the oxidation scale of Si is reduced. The peelability can be suppressed. Further, since N is contained in a relatively small amount, it is difficult to form voids inside the modeled object due to thermal expansion of nitrogen during modeling while preventing the formation of a nitride of Al and a decrease in effective Al. Become. As a result, the modeled object can be modeled more easily while ensuring the high temperature oxidation resistance of the modeled object.

(8) According to another aspect of the present invention, the molding powder or the molding wire made of stainless steel of the present invention has the following constitution in addition to the constitution of any of the above (5) to (7). Is preferable.
It is modeled in an inert atmosphere with oxygen of 1.0 vol% or less.

According to this configuration, the molding powder or molding wire made of stainless steel of the present invention is used in an inert atmosphere having an oxygen content of 1.0 vol% or less, for example, by encapsulating argon gas to reduce oxygen gas and nitrogen gas. It is modeled. As a result, the amount of nitrogen contained in the modeled object is reduced to prevent the formation of Al nitrides and the decrease in effective Al, and the voids inside the modeled object are formed due to the thermal expansion of nitrogen during modeling. It becomes difficult. As a result, the modeled object can be modeled more easily while ensuring the high temperature oxidation resistance of the modeled object.

According to another aspect of the present invention, the molding powder or the molding wire made of the stainless steel of the present invention preferably has the following constitution in addition to the constitution of any one of the above (1) to (8). ..
(9) The molding powder or molding wire made of stainless steel of the present invention contains at least one of Mo, Cu, Ti and / and Nb and REM.
When Mo is contained, 0.2 to 3.0% by weight of Mo is contained.
When Cu is contained, it contains 1.0 to 3.0% by weight of Cu.
When Ti and / and Nb are contained, Ti and / and Nb are contained in an amount of 10 × (C + N) to 0.50% by weight.
When REM is contained, 0.03 to 0.30% by weight of REM is contained.
Alternatively, (10) the modeling powder or modeling wire made of stainless steel of the present invention contains at least one of Mo, Cu, Ti and / and Nb and REM.
When Mo is contained, it contains 1.5 to 2.5% by weight of Mo.
When Cu is contained, it contains 1.5 to 2.5% by weight of Cu.
When Ti and / and Nb are contained, Ti and / and Nb are added in an amount of 10x (C + N) to 0.35% by weight.
When REM is contained, it contains 0.06 to 0.12% by weight of REM.

According to this configuration, since Mo is contained, the heat resistance and corrosion resistance of the modeled object are improved. Since Cu is contained, the heat resistance and corrosion resistance of the modeled object are improved. Further, since Ti or / and Nb are small, the oxidation resistance of the modeled object is unlikely to decrease. Further, since Ti or / and Nb are small, carbides and nitrides of Cr are less likely to be generated at the time of modeling, and modeling can be easily performed. Since REM is included, the thermal fatigue resistance and high temperature oxidation resistance of the modeled object are improved. As a result, the modeled object can be modeled more easily while ensuring the high temperature oxidation resistance of the modeled object.

According to another aspect of the present invention, the molding powder or the molding wire made of the stainless steel of the present invention preferably has the following constitution in addition to the constitution of any one of the above (1) to (10). ..
(11) The particle size distribution of the modeling powder is 1 to 450 μm.
The diameter of the modeling wire is in the range of 0.1 to 3.0 mm.
Alternatively, (12) the particle size distribution of the modeling powder is 5 to 100 μm or 10 to 50 μm.
The diameter of the modeling wire is in the range of 0.1 to 3.0 mm.

Generally, in order to form a complex shaped object having a fine and thin partition wall in the structure layer, a modeling powder having a small particle size or a modeling wire having a small diameter is used. However, if the particle size of the modeling powder is too small, it becomes difficult for the modeling powder to flow during modeling. On the other hand, if the particle size of the modeling powder or the diameter of the modeling wire is too large, it is difficult to form a modeled object having a complicated shape having a fine and thin partition wall in the structure layer, and an unmelted portion is generated. According to this configuration, the particle size of the modeling powder is not too small, and the particle size of the modeling powder is wide. Therefore, it is easier to model the modeled object by using the modeling powder having a particle size suitable for the modeled object. Can be done. Similarly, since the diameter of the modeling wire is not too small and the diameter of the modeling wire is wide, it is possible to more easily model the modeled object by using the modeling wire having a diameter corresponding to the modeled object. ..

According to another aspect of the present invention, the molding powder made of stainless steel of the present invention preferably has the following constitution in addition to the above-mentioned constitution (11) or (12).
(13) A molding powder made of stainless steel that is molded using a laser beam.
The particle size of the modeling powder is in the range of 0.2D to 5.0D with respect to the spot diameter D of the laser beam.
(14) Preferably, it is a molding powder made of stainless steel that is molded using a laser beam.
The particle size of the modeling powder is in the range of 0.2D to 2.0D with respect to the spot diameter D of the laser beam.

According to another aspect of the present invention, the modeling powder or modeling wire made of stainless steel of the present invention has any of the above configurations (4) to (14) in addition to the above configuration (16). Is preferable.

According to another aspect of the present invention, the molding powder or the molding wire made of the stainless steel of the present invention preferably has the following constitution in addition to the above configurations (1) to (14).
(15) The modeling powder or modeling wire made of stainless steel is used for modeling a modeled object by a laminated modeling method involving a rapid melting and quenching solidification process.

(17) The model made of stainless steel of the present invention contains 22 to 36% by weight of Cr and 3 to 15% by weight of Al, and the balance is Fe and unavoidable impurities, and a plurality of structure layers. Is a laminated structure constructed by laminating the above-mentioned structure so that at least a part of the plurality of structure layers forms a gap through which the fluid can pass, and the fluid can pass through the inside through the gap. It is the laminated structure constructed in.

According to this configuration, since a model made of stainless steel contains a relatively large amount of Cr, high temperature oxidation resistance can be improved. Further, since the modeled product made of stainless steel contains a relatively large amount of Cr, the coefficient of thermal expansion is reduced and the dimensional accuracy is improved. Further, since the modeled product made of stainless steel contains a relatively large amount of Cr, the thermal stress of the modeled object at high temperature can be reduced and the thermal fatigue strength can be increased. Al is contained in the modeled product made of stainless steel. Since Al has a low melting point, it is possible to easily model a modeled object. In addition, Al can maintain the high temperature oxidation resistance of the modeled object. Here, when Al is contained in an amount of 3% by weight or more, a stable Al oxide film can be formed and the Cr oxide film can be protected. Further, by containing a large amount of Al, it is possible to prevent all Al from being oxidized and to suppress deterioration of the modeled object due to oxidation of Fe contained in the modeled object. On the other hand, if the amount of Al is too large, the coefficient of thermal expansion of the modeled object becomes high, and the thermal stress of the modeled object at a high temperature becomes high. However, when Al is contained in an amount of 15% by weight or less, preferably 8% by weight or less, the coefficient of thermal expansion of the modeled object can be suppressed and the thermal stress of the modeled object at a high temperature can be reduced. As a result, the modeled object made of stainless steel of the present invention can have a complicated shape. A model with a complicated shape is a laminated structure formed by laminating a plurality of structure layers, and at least a part of the plurality of structure layers forms a gap through which a fluid can pass through a plurality of partition walls. However, it is a laminated structure configured to allow fluid to pass through inside using gaps. Therefore, according to the present invention, it is possible to easily form a modeled object having a complicated shape while ensuring high temperature oxidation resistance of the modeled object which is a laminated structure.

According to another aspect of the present invention, the model made of stainless steel of the present invention preferably has the following constitution in addition to the constitution of (17) above.
(18) The structure layer made of the stainless steel has the gap through which the fluid can pass in the first direction by a plurality of partition walls in at least a part of the cross sections orthogonal to the first direction. Is configured to be laminated in the first direction, and the fluid can be passed in the first direction by using the gaps between the plurality of laminated structure layers.

According to another aspect of the present invention, the model made of stainless steel of the present invention preferably has the following constitution in addition to the constitution of (18) above.
(19) The model made of stainless steel is configured to have a portion in which the partition wall and the gap of the structure layer are lined up in the first direction.

According to another aspect of the present invention, the model made of stainless steel of the present invention preferably has the following constitution in addition to the above-mentioned constitution (18) or (19).
(20) The model made of stainless steel is the laminated structure in which the total volume of the gaps is larger than the total volume of the partition walls.
The "gap" in the present invention and the present specification means a gap inside the outer surface portion of the modeled object. That is, when there is a recess on the outer surface of the modeled object, the space inside the recess on the outer surface of the modeled object is not included in the "gap".

<Definition of terms>
In the present invention and the present specification, the "stainless steel modeling powder or modeling wire" is a stainless steel powder or wire used for modeling a metal model. For example, using a known powder bed method or metal deposition type 3D printer, a modeled object is modeled from the modeling powder or the modeling wire made of the stainless steel of the present invention. "Shaping powder or modeling wire made of stainless steel" is used for modeling a modeled object having a complicated shape. Specifically, a modeled object having a complicated shape is a laminated structure formed by laminating a plurality of structure layers, and at least a part of the plurality of structure layers has a gap through which a fluid can pass. It is a shaped object such as a laminated structure that is formed and configured to allow fluid to pass through inside using gaps. Here, the fluid is, for example, a gas such as air, a liquid such as water, or a viscous fluid. Further, the plurality of structure layers may have the same shape or different shapes from each other. It should be noted that the modeling powder made of stainless steel or the modeling object formed from the modeling wire according to the present invention is used at a high temperature. The complex shaped objects used at high temperatures include, for example, catalyst carriers, electric heaters, turbocharger compressor impellers, wastegate valves, exhaust device (eg EXUP) valves, turbine blades, and the like.

In the present invention and the present specification, the "unavoidable impurities" are those which are present in the raw material or inevitably mixed in the manufacturing process in the molding powder or the molding wire made of the stainless steel of the present invention. Is. Further, the "unavoidable impurity" means an impurity that is originally unnecessary, but is allowed because it is a trace amount and does not affect the characteristics of the modeled object. In the present invention, for example, Ni, Sn and the like correspond to unavoidable impurities. Further, in the present invention, Fe, Cr, Al, C, S, Si, Mn, N, Mo, Cu, Ti, Nb, and REM do not correspond to unavoidable impurities.

In the present invention and the present specification, "10x (C + N)" means 10 times (carbon content + nitrogen content). Further, in the present invention, "Ti and / and Nb" includes the case of Ti alone, the case of Nb alone, or the case of Ti and Nb.

In the present invention and the present specification, the "additive manufacturing method involving a rapid melting and quenching solidification process" is a three-dimensional additive manufacturing method, a thermal spraying method, a laser coating method, an overlay method, and the like. In the "laminated molding method involving rapid melting and quenching solidification process", a melting step of rapidly melting a molding powder or a molding wire made of stainless steel with a laser beam or an electron beam, and a solidification step of rapidly cooling and solidifying are performed. By repeating the process, the structure layers are laminated to form a laminated structure.

In the claims, if the number of certain components is not clearly specified and is displayed in the singular when translated into English, the present invention may have a plurality of these components. Further, the present invention may have only one of these components.

In the present invention, including, comprising, having and derivatives thereof are used intended to include additional items in addition to the listed items and their equivalents. ing.
In the present invention, the terms mounted, connected, coupled, and supported are used in a broad sense. Specifically, it includes not only direct mounting, connection, connection and support, but also indirect mounting, connection, connection and support. Moreover, connected and coupled are not limited to physical or mechanical connections / couplings. They also include direct or indirect electrical connections / couplings.

Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be construed to have meanings consistent with their meaning in the context of the relevant technology and the present disclosure, and are idealized or over-formed. It is not interpreted in a logical sense.

In the present specification, the term "favorable" is non-exclusive. "Preferable" means "preferable, but not limited to". In the present specification, the configuration described as "preferable" exhibits at least the above-mentioned effect obtained by the configuration of claim 1. Also, as used herein, the term "may" is non-exclusive. "May" means "may be, but is not limited to". In the present specification, the configuration described as "may" exerts at least the above-mentioned effect obtained by the configuration of claim 1.

The present invention does not limit the combination of the preferred configurations described above with each other. Prior to discussing embodiments of the invention in detail, it should be understood that the invention is not limited to the details of component configuration and arrangement described in the following description or illustrated in the drawings. The present invention is also possible in embodiments other than the embodiments described later. The present invention is also possible in embodiments in which various modifications are made to the embodiments described later. In addition, the present invention can be implemented by appropriately combining embodiments and modifications described later.

The modeling powder or modeling wire made of stainless steel of the present invention can easily form a modeled object having a complicated shape while ensuring high temperature oxidation resistance of the modeled object which is a laminated structure.

It is explanatory drawing which shows an example of the model | shaped object which is a laminated structure made of stainless steel of this embodiment, and shows the cross section orthogonal to the 1st direction. It is explanatory drawing which shows an example of the model | shaped object which is a laminated structure made of stainless steel of this embodiment, and is the sectional view which follows the 1st direction. It is explanatory drawing which shows another example of the model | shaped object which is a laminated structure made of stainless steel of this embodiment, and is the sectional view which follows the 1st direction.

[Shaping powder or molding wire made of stainless steel of the present embodiment]
The modeling powder or modeling wire made of stainless steel of the present embodiment will be described. The modeling powder or modeling wire made of stainless steel of the present embodiment is made of stainless steel and is used for modeling a modeled object which is a laminated structure made of stainless steel. A method of modeling a modeled object, which is a laminated structure made of stainless steel, using the modeling powder or the modeling wire of the present embodiment will be described below.

The modeling powder or modeling wire made of stainless steel of the present embodiment is used for modeling a modeled object by a laminated modeling method involving a rapid melting and quenching solidification process. For example, the modeling powder made of stainless steel of the present embodiment is modeled into a modeled object which is a laminated structure by a known powder bed type 3D printer. In the powder bed method, a modeled object, which is a laminated structure, is modeled by laying powder for modeling and melting and solidifying the part to be modeled by a laser or an electron beam as a heat source. In the powder bed method, modeling powder is spread and melted and solidified repeatedly to form a modeled object that is a laminated structure. In the powder bed type laser beam heat source method, the spread molding powder is irradiated with a laser beam to be melted and solidified to form a modeled object which is a laminated structure. In the laser beam method, argon gas or the like is sealed, and the modeling powder is melted and solidified in an inert atmosphere containing 1.0 vol% or less of oxygen. In the powder bed type electron beam heat source method, the kinetic energy is converted into heat and the powder is melted, solidified or sintered by irradiating the spread molding powder with an electron beam in a high vacuum and colliding with it. A modeled object that is a laminated structure is laminated. In the electron beam method, the molding powder is melted and solidified in a vacuum.

Further, for example, the molding powder made of stainless steel of the present embodiment is molded into a shaped object which is a laminated structure by a known metal deposit type laser beam heat source type 3D printer. In the metal deposit method, for example, molten modeling powder is laminated and solidified in a predetermined place for modeling. In the laser beam heat source method, the molding powder is injected from the nozzle and at the same time the laser light is irradiated to supply the molding powder to the molten pool and solidified to form a shaped object which is a laminated structure. At this time, the modeling powder is injected using argon gas in an inert atmosphere in which oxygen is 1.0 vol% or less. The melting nozzle or stage is moved according to the shape of the modeled object to form the modeled object on the stage. In the metal deposition method, it is also possible to form a modeled object in which a laminated structure is laminated on the metal object by performing additional machining (building up) on the metal object installed in the 3D printer.

Further, for example, a known metal deposit type arc discharge type 3D printer is used for modeling a modeled object which is a laminated structure made of stainless steel molding wire of the present embodiment. In the metal deposit method, the molten modeling wire is laminated and solidified at a predetermined place to form a modeled object which is a laminated structure. In the arc discharge method, the modeling wire is melted by the arc discharge at the tip of the modeling wire, and the modeled object, which is a laminated structure, is modeled by laminating the wires. In the metal deposition method, it is also possible to form a modeled object in which a laminated structure is laminated on the metal object by performing additional machining (building up) on the metal object installed in the 3D printer.

The material and components of the modeling powder or modeling wire made of stainless steel of the present embodiment will be described. The material of the molding powder or the molding wire of the present embodiment is an alloy steel (stainless steel) containing Fe as a main component and Cr and Al contained. The modeling powder or modeling wire made of stainless steel of the present embodiment contains 10.5 to 36% by weight of Cr and 2 to 15% by weight of Al. The modeling powder or modeling wire made of stainless steel of the present embodiment preferably contains 18 to 28% by weight of Cr. The modeling powder or modeling wire made of stainless steel of the present embodiment more preferably contains 25 to 26% by weight of Cr. The rest of the modeling powder or modeling wire of this embodiment made of stainless steel is Fe and unavoidable impurities. Further, the modeling powder or modeling wire made of stainless steel of the present embodiment preferably contains 5 to 8% by weight of Al. More preferably, the modeling powder or modeling wire of the present embodiment made of stainless steel contains 2.5 to 3.5% by weight or 4.5 to 5.5% by weight of Al.

Cr is chromium. When a relatively large amount of Cr is contained in the molding powder made of stainless steel or the molding wire, the high temperature oxidation resistance of the molding made from the molding powder made of stainless steel or the molding wire is improved. Further, when the modeling powder or the modeling wire made of stainless steel contains a relatively large amount of Cr, the coefficient of thermal expansion of the modeled object becomes small, the modeled object is easily modeled, and the dimensional accuracy is improved. Further, when a relatively large amount of Cr is contained in the modeling powder or the modeling wire made of stainless steel, the thermal stress of the modeled object at high temperature can be lowered and the thermal fatigue strength can be increased.

Al is aluminum. Al has a low melting point. When the modeling powder or the modeling wire made of stainless steel contains Al having a low melting point, the modeled object can be easily modeled. In addition, Al can maintain the high temperature oxidation resistance of the modeled object. Here, when Al is contained in an amount of 2% by weight or more, a stable Al oxide film can be formed and the Cr oxide film can be protected. Further, by containing a large amount of Al, it is possible to prevent all Al from being oxidized and to suppress deterioration of the modeled object due to oxidation of Fe contained in the modeled object. On the other hand, if the amount of Al is too large, the coefficient of thermal expansion of the modeled object becomes high, and the thermal stress of the modeled object at a high temperature becomes high. However, when Al is contained in an amount of 15% by weight or less, preferably 8% by weight or less, the coefficient of thermal expansion of the modeled object can be suppressed and the thermal stress of the modeled object at a high temperature can be reduced.

Further, the modeling powder or modeling wire made of stainless steel of the present embodiment may contain 0.1 to 1.5% by weight of Si.

Si is silicon. By containing 0.1 to 1.5% by weight of Si in the molding powder or the molding wire made of stainless steel, the diameter of the particles of the molding powder made of stainless steel or the molding wire is relatively small. Can be done. By reducing the diameter of the modeling powder particles or the modeling wire made of stainless steel, the modeling powder or the modeling wire is easily melted in the melting process, and the modeled object can be easily modeled.

The molding powder or molding wire made of stainless steel of the present embodiment preferably contains C in an amount of 0.015% by weight or less, S in an amount of 0.015% by weight or less, and Si in an amount of 0.1 to 1.5% by weight. Mn may be contained in an amount of 0.1 to 2.0% by weight and N may be contained in an amount of 0.040% by weight or less.

Preferably, the modeling powder or modeling wire made of stainless steel of the present embodiment contains C of 0.015% by weight or less, S of 0.01% by weight or less, and Si of 0.4 to 0.8% by weight. Mn may be contained in an amount of 0.30 to 0.50% by weight, and N may be contained in an amount of 0.020% by weight or less.

Further, preferably, in the modeling powder or modeling wire made of stainless steel of the present embodiment, C is 0.008% by weight or less, S is 0.002% by weight or less, Si is 0.15% by weight or less, and Mn. May be contained in an amount of 0.30% by weight or less and N may be contained in an amount of 0.015% by weight or less.

C is carbon. Since the molding powder or molding wire made of stainless steel contains a relatively small amount of C, the oxidation resistance of stainless steel is improved, and carbides and nitrides of Cr are less likely to be generated during molding, so that molding is easy. Can be done.

S is sulfur. Since the molding powder or molding wire made of stainless steel contains a relatively small amount of S, the oxidation resistance of stainless steel is improved, and carbides and nitrides of Cr are less likely to be generated during molding, so that molding is easy. Can be done.

Si is silicon as described above. If the molding powder or the molding wire made of stainless steel contains too much Si, the peeling resistance of the oxidation scale will decrease, but if the Si content is too small, the high temperature oxidation resistance of the model will decrease. By appropriately containing Si, a Si oxide film can be formed under the Cr oxide film, and the oxidation rate of the modeled object can be delayed.

Mn is manganese. If the modeling powder or modeling wire made of stainless steel contains too much Mn, the oxidation rate of the modeled object will be increased, and the oxidation resistance and corrosion resistance of the modeled object will deteriorate, but the Mn content will be relatively small. Since it is contained, the peeling resistance of the oxidation scale of Si can be suppressed.

N is nitrogen. Since the molding powder or the molding wire made of stainless steel contains a relatively small amount of N, nitrogen thermally expands during molding while preventing the formation of a nitride of Al and a decrease in effective Al. As a result, it becomes difficult to form voids inside the modeled object. In particular, the modeling powder or modeling wire made of stainless steel of the present embodiment is modeled in an inert atmosphere in which, for example, argon gas is sealed to reduce nitrogen gas and oxygen gas, and oxygen is 1.0 vol% or less. NS. As a result, the amount of nitrogen contained in the modeled object can be reduced.

Further, the modeling powder or modeling wire made of stainless steel of the present embodiment may contain at least one of Mo, Cu, Ti and / and Nb and REM.

Specifically, when the molding powder or the molding wire made of stainless steel of the present embodiment contains Mo, 0.2 to 3.0% by weight of Mo, and contains Cu, When Cu is contained in an amount of 1.0 to 3.0% by weight and Ti and / and Nb are contained, Ti and / and Nb are contained in an amount of 10 × (C + N) to 0.50% by weight and REM is contained. In the case, REM may be contained in an amount of 0.03 to 0.30% by weight.

Alternatively, the molding powder or molding wire made of stainless steel of the present embodiment contains 1.5 to 2.5% by weight of Mo when Mo is contained, and 1 Cu when Cu is contained. .5 to 2.5% by weight, Ti and / and Nb in 10x (C + N) to 0.35% by weight, REM in 0. It may be contained in an amount of 06 to 0.12% by weight.

Mo is molybdenum. Since Mo is contained in the modeling powder or the modeling wire made of stainless steel, the heat resistance and corrosion resistance of the modeled object are improved.

Cu is copper. Since Cu is contained in the modeling powder or the modeling wire made of stainless steel, the heat resistance and corrosion resistance of the modeled object are improved.

Ti is titanium. Nb is niobium. Since the modeling powder or the modeling wire made of stainless steel contains a small amount of Ti and / / Nb, the oxidation resistance of the modeled object is unlikely to decrease. Further, since Ti or / and Nb are contained in a small amount, carbides and nitrides of Cr are less likely to be generated at the time of modeling, and modeling can be easily performed.

REM is a rare earth metal, such as Ce (cesium), La (lanthanum), and Y (itnium). Since the modeling powder or the modeling wire made of stainless steel contains REM, the thermal fatigue resistance and the high temperature oxidation resistance of the modeled object are improved.

The shape of the molding powder made of stainless steel of the present embodiment will be described.
The molding powder made of stainless steel of the present embodiment is made spherical by a gas atomizing method, a water atomizing method, or the like. The molding powder made of stainless steel of the present embodiment has a particle size distribution of 1 to 450 μm, preferably 1 to 300 μm, more preferably 5 to 100 μm, and even more preferably 10 to 50 μm. When the molding powder made of stainless steel of the present embodiment is a molding powder made of stainless steel formed by using a laser beam, the molding powder made of stainless steel of the present embodiment has a spot diameter D of the laser beam. On the other hand, the particle size is in the range of 0.2D to 5.0D, preferably in the range of 0.2D to 2.0D.

The shape of the molding wire made of stainless steel of the present embodiment will be described.
The molding wire made of stainless steel of the present embodiment has a diameter in the range of 0.1 to 3.0 mm.

Generally, in order to form a complex shaped object having a fine and thin partition wall in the structure layer, a modeling powder having a small particle size or a modeling wire having a small diameter is used. However, if the particle size of the modeling powder is too small, it becomes difficult for the modeling powder to flow during modeling. On the other hand, if the particle size of the modeling powder or the diameter of the modeling wire is too large, it is difficult to form a modeled object having a complicated shape having a fine and thin partition wall in the structure layer, and an unmelted portion is generated. According to this configuration, the particle size of the molding powder made of stainless steel is not too small, and the particle size of the molding powder made of stainless steel is wide. Therefore, the molding powder made of stainless steel having a particle size corresponding to the modeled object. It is possible to more easily form a modeled object which is a laminated structure by using. Similarly, since the diameter of the modeling wire made of stainless steel is not too small and the width of the diameter of the modeling wire made of stainless steel is wide, it is made of stainless steel having a diameter corresponding to the modeled object which is a laminated structure. A modeled object, which is a laminated structure, can be modeled more easily by using the modeling wire.

From the above, the modeling powder or the modeling wire made of stainless steel of the present embodiment can more easily form the modeled object while ensuring the high temperature oxidation resistance of the modeled object.

[Modeled product made of stainless steel according to this embodiment]
The modeling powder or modeling wire made of stainless steel of the present embodiment is used for modeling a modeled object having a complicated shape. A model having a complicated shape is, for example, a laminated structure formed by laminating a plurality of structure layers, and a gap through which at least a part of the plurality of structure layers allows fluid to pass through a plurality of partition walls. It is a laminated structure that is configured to allow fluid to pass through inside using gaps.

An example of a modeled object made of stainless steel according to this embodiment will be described with reference to FIGS. 1 (a) and 2. As shown in FIGS. 1A and 2A, the modeled object 1 is configured by stacking a plurality of structure layers 4 in the first direction. The structure layer 4 has a gap 3 through which a fluid can pass in the first direction by a plurality of partition walls 2 in at least a part of the cross sections orthogonal to the first direction. Then, the modeled object 1 is configured so that the fluid can pass in the first direction using the gaps 3 of the plurality of laminated structure layers 4. As shown in FIG. 2B, the modeled object 1 may be configured to have a portion in which the partition wall 2 and the gap 3 of the structure layer 4 are lined up in the first direction.

Another example of the modeled object made of stainless steel of the present embodiment will be described with reference to FIGS. 1 (b) and 3. As shown in FIGS. 1B and 3A, the modeled object 1 is configured by stacking a plurality of structure layers 4 in the first direction. The structure layer 4 has a gap 3 through which a fluid can pass through in a direction orthogonal to the first direction by a plurality of partition walls 2 in at least a part of the cross sections orthogonal to the first direction. The direction orthogonal to the first direction is the vertical direction of the paper surface in FIG. 1 (b) and the left-right direction of the paper surface in FIG. Then, the modeled object 1 is configured so that the fluid can pass in the direction orthogonal to the first direction by using the gaps 3 of the plurality of laminated structure layers 4. Here, as shown in FIG. 3B, the modeled object 1 may be configured to have a portion in which the partition wall 2 and the gap 3 of the structure layer 4 are lined up in the first direction.

Here, the model 1 made of stainless steel of the present embodiment may be a laminated structure in which the total volume of the gap 3 is larger than the total volume of the partition wall 2. For example, the model 1 made of stainless steel of the present embodiment is a laminated structure in which the total volume of the gaps 3 is larger than the total volume of the partition walls 2 within 1 cubic cm. For example, in the model 1 made of stainless steel of the present embodiment, when the laminated structure has a lattice structure, the total volume of the gap 3 with respect to the volume of the laminated structure within 1 cube is 30% at the maximum. It is modeled. Further, for example, in the model 1 made of stainless steel of the present embodiment, when the laminated structure has a gyroid structure, the total volume of the gap 3 with respect to the volume of the laminated structure within 1 cube is 40% at maximum. It is shaped as it is.

Examples of the stainless steel molding powder of the present embodiment, which is used for modeling the stainless steel model of the present embodiment, will be described with reference to Tables 1 to 3. The embodiment of the molding wire made of stainless steel of the present embodiment is the same as the embodiment of the molding powder made of stainless steel of the present embodiment, and the description thereof will be omitted.

Table 1 is a table showing the components of the molding powder made of stainless steel of this example and the components of the molding powder made of stainless steel of the comparative example. Table 1 shows the components contained in the examples of the molding powder made of stainless steel of the present invention.

Examples 1 to 3 shown in Table 1 are examples of a molding powder made of the stainless steel of the present invention, which is a 25Cr-5Al-based stainless steel powder.

As shown in Table 1, the molding powder made of stainless steel of Examples 1 to 3 contains Cr in the range of 10.5 to 36% by weight and in the range of 18 to 28% by weight. There is. Further, the molding powder made of stainless steel of Examples 2 and 3 contains Cr in the range of 25 to 26% by weight.

Further, the molding powder made of stainless steel of Examples 1 to 3 contains Al in the range of 2 to 15% by weight. Further, the molding powder made of stainless steel of Examples 2 and 3 contains Al in the range of 2.5 to 3.5% by weight or 4.5 to 5.5% by weight.

As shown in Table 1, the molding powder made of stainless steel of Examples 1 to 3 contains 0.015% by weight or less of S, 0.015% by weight or less of S, and 0.1 to 1.5% by weight of Si. , Mn is contained in the range of 0.1 to 2.0% by weight, and N is contained in the range of 0.040% by weight or less. Further, in the modeling powder made of stainless steel of Example 2, C is 0.015% by weight or less, S is 0.01% by weight or less, Si is 0.4 to 0.8% by weight, and Mn is 0.30. It contains ~ 0.50% by weight and N in the range of 0.020% by weight or less. The modeling powder made of stainless steel of Example 3 had C of 0.008% by weight or less, S of 0.002% by weight or less, Si of 0.15% by weight or less, Mn of 0.30% by weight or less, and N. Is contained in the range of 0.015% by weight or less.

Table 2 is a table showing the components that can be added to the molding powder made of stainless steel of this example. Table 2 shows Examples 4 and 5 containing an element that can be added to the molding powder made of stainless steel of the present invention as a component. Examples 4 and 5 have components as shown in Examples 1 to 3 in Table 1 in addition to the components shown in Table 2.

As shown in Table 2, in Example 4, Mo was 0.2 to 3.0% by weight, Cu was 1.0 to 3.0% by weight, and Ti or / and Nb were 10 × (C + N) to 0. It contains 50% by weight and REM in the range of 0.03 to 0.30% by weight. In Example 5, Mo was 1.5 to 2.5% by weight, Cu was 1.5 to 2.5% by weight, Ti or / and Nb was 10X (C + N) to 0.35% by weight, and REM was 0. It is contained in the range of 06 to 0.12% by weight.

Table 3 is a table showing the characteristics of the particles of the molding powder made of stainless steel of this example. Table 3 shows the particle characteristics of Examples 5 and 6, which are powders for modeling made of stainless steel of the present invention.

In Table 3, the bulk density is a volume obtained by filling a container having a certain volume with a container for modeling by a certain method and including voids between particles, and dividing the weight of the powder for modeling. The average particle size means the particle size at an integrated value of 50% in the particle size distribution of the modeling powder obtained by the laser diffraction / scattering method. The particle distribution is an index showing what size (particle size) of particles are contained in the modeling powder in what proportion. The fluidity is a value indicating the ease of flow of the modeling powder. The angle of repose is the angle between the slope of the mountain and the horizontal plane of the modeling powder that is formed when the modeling powder is dropped from a certain height and remains stable without spontaneously collapsing. The spatula angle is the angle of a mountain formed when a spatula (metal spatula) with the measurement surface facing up is horizontally embedded in the deposited molding powder and the spatula is lifted in the vertical direction. The degree of compression is the difference between the bulk density and the loose bulk density with respect to the bulk density.

As shown in Table 3, the molding powder made of stainless steel of Example 5 has a particle size distribution in the range of 1 to 300 μm. The molding powder made of stainless steel of Example 6 has a particle size distribution in the range of 5 to 100 μm or 10 to 50 μm. As shown in Table 3, it can be seen that the modeling powder made of stainless steel of Examples 5 and 6 can secure the fluidity of the modeling powder at the time of modeling.

From the above, the molding powder made of stainless steel of Examples 1 to 3 has the same effect as the molding powder made of stainless steel of the above-described embodiment. The modeling powder made of stainless steel of Examples 1 to 3 can more easily form a model having a complicated shape while ensuring high temperature oxidation resistance of the model as a laminated structure. I understand.

The modeling powder or modeling wire made of stainless steel according to the present invention is used for modeling a modeled object having a complicated shape. The molding powder or molding wire made of stainless steel according to the present invention and the molding made of stainless steel according to the present invention are shaped objects used at high temperatures (for example, a catalyst carrier, an electric heater, a compressor impeller for a turbocharger). , Westgate valves, valves for exhaust devices (eg EXUP), turbine blades, etc.).

1: Modeled object, 2: Partition wall, 3: Gap, 4: Structure layer

Claims

It contains 10.5 to 36% by weight of Cr and 2 to 15% by weight of Al, and the balance is Fe and unavoidable impurities.
A laminated structure in which a plurality of structure layers are laminated, and at least a part of the plurality of structure layers forms a gap through which a fluid can pass, and the fluid is allowed to flow inside using the gap. A modeling powder or modeling wire made of stainless steel, which is used for modeling a modeled object such as the laminated structure, which is configured to be able to pass through.
The modeling powder or modeling wire made of stainless steel according to claim 1, which contains 18 to 28% by weight of Cr.
The molding powder or molding wire made of stainless steel according to claim 1 or 2, which contains 2.5 to 3.5% by weight or 4.5 to 5.5% by weight of Al. ..
The modeling powder or modeling wire made of stainless steel according to any one of claims 1 to 3, characterized by containing 0.1 to 1.5% by weight of Si.
Claims 1 to 1, wherein C is contained in an amount of 0.015% by weight or less, S is contained in an amount of 0.015% by weight or less, Mn is contained in an amount of 0.1 to 2.0% by weight, and N is contained in an amount of 0.040% by weight or less. A molding powder or a molding wire made of the stainless steel according to any one of 4.
The modeling powder or modeling wire made of stainless steel according to claim 5, characterized in that oxygen is formed in an inert atmosphere of 1.0 vol% or less.
Contains at least one of Mo, Cu, Ti and / and Nb, REM,
When Mo is contained, 0.2 to 3.0% by weight of Mo is contained.
When Cu is contained, it contains 1.0 to 3.0% by weight of Cu.
When Ti and / and Nb are contained, Ti and / and Nb are contained in an amount of 10 × (C + N) to 0.50% by weight.
A molding powder or a molding wire made of stainless steel according to any one of claims 1 to 6, wherein when REM is contained, the REM is contained in an amount of 0.03 to 0.30% by weight. ..
The particle size distribution of the modeling powder is 1 to 450 μm or 1 to 300 μm.
The modeling powder or modeling wire made of stainless steel according to any one of claims 1 to 7, wherein the diameter of the modeling wire is in the range of 0.1 to 3.0 mm.
The modeling powder made of stainless steel according to claim 8, which is formed by using a laser beam.
The particle size of the modeling powder is in the range of 0.2D to 5.0D with respect to the spot diameter D of the laser beam.
The modeling powder or modeling wire made of stainless steel according to any one of claims 1 to 8, which is used for modeling a modeled object by a laminated modeling method involving a rapid melting and quenching solidification process.
It contains 22 to 36% by weight of Cr and 2 to 15% by weight of Al, and the balance is Fe and unavoidable impurities. Molding powder or molding wire made of stainless steel.
It contains 22 to 36% by weight of Cr and 3 to 15% by weight of Al, and the balance is Fe and unavoidable impurities.
A laminated structure in which a plurality of structure layers are laminated, and at least a part of the plurality of structure layers forms a gap through which a fluid can pass, and the fluid is allowed to flow inside using the gap. A model made of stainless steel, which is the laminated structure configured so that it can pass through.
In a cross section orthogonal to at least a part of the first direction, a plurality of the structure layers having the gap through which the fluid can pass in the first direction are laminated in the first direction by a plurality of partition walls. The model made of stainless steel according to claim 12, which is configured to allow fluid to pass in the first direction using the gaps between the plurality of the structural layers.
The model made of stainless steel according to claim 13, which is configured to have a portion in which the partition wall and the gap of the structure layer are lined up in the first direction.
The model made of stainless steel according to any one of claims 13 or 14, wherein the total volume of the gaps is larger than the total volume of the partition walls.