Steel powder mixture for additive manufacturing of components, preferably components for production of machine and vehicle constructions

Abstract

The invention relates to a steel powder mixture for the additive manufacturing of parts, preferably for the production of parts of machine and vehicle constructions, consisting of a low alloy steel having a high yield strength and yield point, a breaking strength of up to 18%, a tensile strength of up to 900 N / mm2 and a hardness of-30 HR.

Description

[0001] The present invention relates to a steel powder mixture for the additive manufacturing of components, preferably for the production of components, for example for machine and vehicle construction, agricultural and forestry machines and steel construction.

[0002] The production of components using additive manufacturing methods (also known as 3D printing) is known, wherein selective laser melting (SLM) is used in a powder bed method. In this method, the component structure is generated by melting and solidifying the steel powder mixture used layer by layer.

[0003] EP 3591078 A1 discloses the use of a steel powder for an additive manufacturing method, wherein a steel having an average particle size of 5-150 μm is provided, the steel consisting of (in wt. %) 0.008-0.35% C, up to 0.80% Si, 0.20-2.0% Mn, up to 4.00% Cr, 0.3-3.0% Mo, 0.004-0.020% N, up to 0.40% S, 0.004-0.050% Al, up to 0.0025% B, up to 0.001% C, up to 0.002% C, up to 0.003% C, up to 0.006% C, up to 0.007% C, up to 0.008% C, up to 0.009% C, up to 0.10% C, up to 0.15 ... .20% Nb, at most 0.02% Ti, at most 0.40% V, at most 1.5% Ni, at most 0.3% Cu, at most 2.0% Co, and the balance being iron and unavoidable impurities, wherein the Al content in the steel is calculated as %Al, the Nb content is calculated as %Nb, the Ti content is calculated as %Ti, the V content is calculated as %V, and the N content is calculated as %N, satisfying the following conditions: %Al / 27+%Nb / 45+%Ti / 48+%V / 25>%N / 3.5.

[0004] From WO 2020221812 A1, a steel material in powder form is known for printing in additive manufacturing methods, such as selective laser melting, wherein the material has the following composition: C 0.17-0.23; Si 0.10-0.80; Mn 0.15-0.45, P≤0.03; S≤0.015; Cr 0.8-2.0; Mo 0.15-0.8; Ni 0.1-2.0; V 0.1-2.0, the balance being iron.

[0005] These known steel materials are primarily stainless steels or tool steels employed in tool construction.

[0006] The object of the present invention is to specify a steel powder mixture for the additive production of components which meets in particular the requirements of machine and vehicle construction.

[0007] The invention results from the features of the independent claims. Advantageous further developments and configurations are the subject matter of the dependent claims. Further features, possible applications and advantages of the invention are derived from the following description and from the explanation of exemplary embodiments of the invention.

[0008] This object is achieved with the subject matter of patent claim 1 .

[0009] The steel powder mixture detailed above is composed of a steel powder having a strength of at least 800 N / mm 2 High yield strength and yield point, up to 18% of the breaking strength, up to 900N / mm 2 The powder is composed of a low-alloy steel with a tensile strength of 1000 psi and a hardness of ~30 HRC. These properties make it particularly suitable for producing machine and vehicle parts, agricultural and forestry components, and steel structures, as no subsequent heat treatment is required. These components can be produced in any volume, eliminating the need for expensive warehousing. This also reduces scrap costs (saving resources).

[0010] Advantageously, the low alloy steel consists of (in wt. %) 0.05% C, 0.5% Si, 1.1% Mn, 0.01 P, 0.002% S, 0.01% Al, 0.002% Ti, 0.01% V, 0.06% Nb, 0.04% N and 0.04% O, the balance being Fe.

[0011] In one configuration, the powder has particles with a size of 23 μm to 50 μm. In this configuration, the particle size distribution reaches D10~23 μm, D50~34.0 μm and D90~50 μm.

[0012] Components produced in additive manufacturing methods from the described steel powder mixture are highly machinable, deformable, and characterized by very good weldability. They are therefore particularly suitable for hybrid manufacturing methods.

[0013] Another aspect of the present invention relates to a method for the generative production of components, in which a selective laser melting method is used as a 3D printing method in a powder bed process. The component structure is produced in the laser melting process by melting and solidifying a steel powder mixture layer by layer, and the steel powder mixture used is a steel powder mixture according to at least one of the features described in this patent application. This method facilitates short production times, whereby the products produced using this method are ready for further use in a very short time without requiring complex tool design. Advantageously, the components can be manufactured to customer specifications. Furthermore, downtimes due to supply gaps, as in conventional manufacturing, can be bridged.

[0014] Bionic adaptations can be created according to individual requirements. Additively manufactured lattice structures reduce component weight. Due to the high complexity of the structures, selective laser melting (SLM) is suitable for producing additively manufactured lattice structures, particularly due to its targeted geometric effects. Layer-by-layer construction enables the manufactured component to assume any shape. The method-dependent forming freedom allows the manufacture of components that cannot be manufactured conventionally. Furthermore, new products can be designed with performance characteristics that cannot be achieved with conventional production methods.

[0015] Further advantages, features and details emerge from the following description, in which at least one exemplary embodiment is described in detail. The features described and / or illustrated in the drawings may constitute the subject matter of the invention individually or in any reasonable combination, optionally even independently of the claims, and in particular also the subject matter of one or more separate applications.

[0016] Table 1 below shows an exemplary embodiment of a steel powder mixture according to the invention for use in machine and vehicle construction, as well as agricultural and forestry vehicles, steel construction, etc., for the additive manufacturing of components using a 3D printing method. Production takes place using a powder bed method, in which the steel powder mixture is melted and then solidified layer by layer by a laser beam.

[0017] Table 1.

[0018] In this process, a particle size distribution is produced in which 10% (D10) of the particles are smaller than 23 μm, 50% (D50) of the particles are smaller than 34 μm and 90% (D90) of the particles are smaller than 50 μm.

[0019] Metal components manufactured from this steel powder mixture have excellent yield strength and yield point for the production of machine and vehicle components. In addition, they achieve an elongation at break of up to 18% and a strength of up to 900 N / mm 2 The tensile strength is not required. No subsequent heat treatment is required. The metal alloy has a hardness (HRC) of ~30.

Claims

1. A steel powder mixture for the additive manufacturing of components, preferably for the production of components for machine and vehicle construction, the steel powder mixture consisting of a steel powder mixture having a strength of at least 800 N / mm 2 High yield strength and yield point, up to 18% of the breaking strength, up to 900N / mm 2 It is composed of low alloy steel with a tensile strength of 1000Nm and a hardness of ~30HRC.

2. The steel powder mixture according to claim 1, characterized in that The low alloy steel consists of (in weight %) 0.05% C, 0.5% Si, 1.1% Mn, 0.01P, 0.002% S, 0.01% Al, 0.002% Ti, 0.01% V, 0.06% Nb, 0.04% N and 0.04% O, with the balance being Fe.

3. The steel powder mixture according to claim 1 or 2, characterized in that The particle size is between 23 μm and 50 μm.

4. The steel powder mixture according to claim 1, 2 or 3, characterized in that The powder has a particle size distribution of D10 to 23 μm, D50 to 34.0 μm, and D90 to 50 μm.

5. A method for the generative production of components, wherein a selective laser melting method is used as a 3D printing method in the powder bed method, wherein the component structure is produced in the laser melting method by melting and solidifying a steel powder mixture layer by layer, characterized in that Use is made of a steel powder mixture according to the preceding claims.

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