Metal component and method for its production

Abstract

Metal component (36) made of or with at least one component (42) resistant to high-temperature corrosion and / or high-temperature abrasion, which consists of a steel alloy with the following chemical composition in weight %: C: 0.01 to 1.0, Al: 3.0 to 12.0, Cr: 1.0 to 15.0, Mn: 5.0 to 30.0 and Si: 0.1 to 4.0, Remainder iron and smelting-related impurities, optionally supplemented by one or more of the following elements with the corresponding proportion in weight % of the composition: Cu: 0.001 to 1.5, Ni: 0.001 to 5.0, S: 0.001 to 0.010, N: 0.001 to 0.010, B: 0.00005 to 0.0250, Ti: 0.01 to 1.0, V: 0.01 to 1.0, Nb: 0.01 to 1.0, Y: 0.001 to 0.1, La: 0.001 to 0.1, Ce: 0.001 to 0.1, Hf: 0.001 to 0.1, Sr: 0.001 to 0.1 and Zr: 0.001 to 0.1, characterized in that the at least one component (42) of the metal component (36) which is resistant to high-temperature corrosion and / or high-temperature abrasion is a component (42) produced by means of additive manufacturing.

Description

[0001] The invention relates to a metal component with at least one component made of an AlCroMaSt steel alloy that is resistant to high-temperature corrosion and / or high-temperature abrasion. The invention further relates to a method for producing such a metal component.

[0002] The main application area for such metal components is the high-temperature range. Such metal components are, in particular, components that (i) operate continuously at particularly high temperatures, for example, in the vicinity of blast furnaces, steelworks, or power plants; (ii) are operated particularly under oxidizing conditions (keyword: scale resistance); (iii) are subject to extreme temperature changes, such as parts in the exhaust system of an internal combustion engine (hot end, cold end), a fuel cell, or a turbine; (iv) and / or are simultaneously subject to abrasive wear at high temperatures, such as in injection devices with solid or liquid media, e.g., nozzle needles in blast furnaces; and / or (v) are used in corrosive media.

[0003] Largely analogous to the description of the steel alloy of AlCroMaSt (AlCroMaSt: aluminum / chromium / manganese steel) in the document WO 2019 / 002041 A1, in the context of the invention described here, an AlroMaSt steel alloy is to be understood in the most general description as a steel alloy with the following chemical composition in weight%: C: 0.01 to 1.0, Al: 3.0 to 12.0, Cr: 1.0 to 15.0, Mn: 5.0 to 30.0 and Si: 0.1 to 4.0, optionally supplemented by one or more of the following elements with a corresponding proportion in weight% of the composition: Cu: 0.001 to 1.5, Ni: 0.001 to 5.0, S: 0.001 to 0.010, N: 0.001 to 0.010, B: 0.00005 to 0.0250, Ti: 0.01 to 1.0, V: 0.01 to 1.0, Nb: 0.01 to 1.0, Y: 0.001 to 0.1, La: 0.001 to 0.1, Ce: 0.001 to 0.1, Hf: 0.001 to 0.1, Sr: 0.001 to 0.1 and Zr: 0.001 to 0.1, balance iron and smelting impurities. The steel alloy is also referred to in this document as a steel alloy with improved corrosion resistance under high-temperature stress.

[0004] From the document DE 10 2015 117 956 A1, a metal component designed as a composite pipe is known which, in addition to a component made of an AlCroMaSt steel alloy that is resistant to high-temperature corrosion and / or high-temperature abrasion, also has a further component that forms a basic element of the metal component.

[0005] The component resistant to high-temperature corrosion and / or high-temperature abrasion is designed as a protective tube, and the other component forming the base element is designed as a support tube made of non-corrosive-resistant steel, to which the protective tube is mechanically or metallurgically bonded by plating. The protective tube acts as a kind of protective layer for the support tube.

[0006] High-temperature corrosion is generally understood to be the chemical reaction between an environment (medium) and a material surface (component) at temperatures that are too high for aqueous corrosion media (electrolytes). The result is the formation of solid, liquid, or gaseous corrosion products, which usually leads to a weakening of the load-bearing cross-section of a component or to a deterioration of its function. Examples of high-temperature corrosion processes can be found in all technical applications that operate at temperatures well above 100 °C, ranging from scaling processes in vehicle exhaust systems to high-temperature corrosion processes in thermal power plants (fired with coal, oil, gas, biomass, hydrogen, residues) to corrosion in aircraft engines and marine diesel engines, as well as in chemical and petrochemical processes.In the context of the invention, high-temperature abrasion is understood to mean abrasion at corresponding temperatures.

[0007] If the component of the metal component resistant to high-temperature corrosion and / or high-temperature abrasion takes the form of such a protective layer, various options are available for manufacturing this component from an AlCroMaSt steel alloy. However, if this component is to have a special shape, for example, a customized shape for the individual metal component or individual sections of the metal component, a special surface structure, the largest possible surface area, and / or be mechanically or metallurgically bonded to another component in a relatively inaccessible location, the aforementioned plating often reaches the limits of what is feasible.

[0008] It is an object of the invention to provide a metal component and a method for producing such a metal component in which these limits have been or will be overcome.

[0009] According to the invention, the object is achieved by the features of the independent claims. Preferred embodiments of the invention are specified in the subclaims, each of which may represent an aspect of the invention individually or in combination.

[0010] In the metal component according to the invention made of or with at least one component resistant to high-temperature corrosion and / or high-temperature abrasion made of a steel alloy with the following chemical composition in % by weight: C: 0.01 to 1.0, Al: 3.0 to 12.0, Cr: 1.0 to 15.0, Mn: 5.0 to 30.0 and Si: 0.1 to 4.0, optionally supplemented by one or more of the following elements with a corresponding proportion in % by weight of the composition: Cu: 0.001 to 1.5, Ni: 0.001 to 5.0, S: 0.001 to 0.010, N: 0.001 to 0.010, B: 0.00005 to 0.0250, Ti: 0.01 to 1.0, V: 0.01 to 1.0, Nb: 0.01 to 1.0, Y: 0.001 to 0.1, La: 0.001 to 0.1, Ce: 0.001 to 0.1, Hf: 0.001 to 0.1, Sr: 0.001 to 0.1 and Zr: 0.001 to 0.1, the remainder being iron and impurities resulting from the melting process, it is provided that at least one component of the metal component which is resistant to high-temperature corrosion and / or high-temperature abrasion is a component produced by means of additive manufacturing.As an alternative to the embodiment of the invention in which the metal component comprises the additional component, it is provided that the metal component consists entirely of the at least one component resistant to high-temperature corrosion and / or high-temperature abrasion. Here, the additive construction does not take place on an additional component of the metal component, but rather on a substrate separate from the metal component. Following construction, the metal component and substrate are separated from each other. Additive manufacturing, also known by the much more popular term 3D printing, is a comprehensive term for all manufacturing processes in which material is applied layer by layer, thus creating three-dimensional objects (workpieces).In the context of the invention, this of course always refers to metal-based additive manufacturing, more precisely to direct additive manufacturing, in which the said component of the metal component with full properties is created directly and immediately through the additive structure.

[0011] By manufacturing the high-temperature corrosion- and / or high-temperature abrasion-resistant component from an AlCroMaSt steel alloy using an additive manufacturing process, it is possible to produce this component or the component containing this component relatively inexpensively, even in small series or as a single piece. This opens up significantly more possibilities regarding the design of the component or the metal component containing this component.

[0012] This type of manufacturing is also well suited for the restoration, overhaul, repair, or improvement (e.g. iterative revision in prototyping) of the metal component.

[0013] According to a preferred embodiment of the invention, the metal component has a further metal component, which is designed in particular as a metal base element and on which the at least one component resistant to high-temperature corrosion and / or high-temperature abrasion is arranged. The at least one component resistant to high-temperature corrosion and / or high-temperature abrasion is mechanically or metallurgically bonded to the further component via its additive manufacturing. In particular, the at least one component resistant to high-temperature corrosion and / or high-temperature abrasion complements the further component to form the metal component.

[0014] It is advantageously provided that the at least one component resistant to high-temperature corrosion and / or high-temperature abrasion forms a protective element, in particular a protective coating, for at least part of the surface of the base element. The additional component is generally far less resistant with regard to its corresponding wear properties than the component resistant to high-temperature corrosion and / or high-temperature abrasion, which thus protects the additional component against such wear. This allows a significantly less expensive metal material to be used for the remaining component.

[0015] In this embodiment, it is particularly provided that at least one part of the surface of the base element covered by the protective element or one of the protective elements is an end region of the base element. The function of the protective element can extend beyond that of a pure protective layer and include additional functions, such as a heat-conducting and / or flow-conducting function.

[0016] Alternatively, it is advantageously provided that the metal component is an additively manufactured hybrid pressure component which, in addition to the at least one component resistant to high-temperature corrosion and / or high-temperature abrasion, has at least one other component produced by additive manufacturing from a steel with a different steel alloy.

[0017] According to a further preferred embodiment of the invention, the metal component is a blowing lance for blowing additional fuel into the tuyeres of a blast furnace. Such a blowing lance offers both resistance to high-temperature corrosion (especially scaling) and resistance to high-temperature abrasion.

[0018] Alternatively, it is advantageously provided that the metal component is a flat product, in particular a flat steel product.

[0019] Preferably, the metal component is a high-temperature metal component for use at temperatures above 300°C, preferably above 800°C.

[0020] Different components of the chemical composition of the AlCroMaSt steel alloy have proven particularly favorable for different applications. These are (in weight %): For high temperature stress for operating temperatures from 300°C to 1200°C, in particular 450°C to 1100°C: C: > 0.01 to 0.40%; Al: 3.0 to 10%; Cr: 1.5 to 6.0%; Mn: 18 to 26.0% and Si: 0.1 to 1.5% and optional alloying of at least one of the rare earth elements Y, La, Ce, or the elements Hf, Sr and Zr.

[0021] For high temperature stress for operating temperatures from 300°C to 1200°C, in particular 850°C to 1100°C: C: > 0.01 to 0.40%; Al: 3.0 to 10%; Cr: 2.5 to 6.0%; Mn: 18 to 26.0% and Si: 0.1 to 2.0% and optional alloying of at least one of the rare earth elements Y, La, Ce, or the elements Hf, Sr and Zr.

[0022] For high temperature stress for operating temperatures from 300°C to 1200°C, in particular 750°C to 1200°C: : C > 0.01 to 0.90%; Al: 3.0 to 10%; Cr: 1.5 to 15.0%; Mn: 8 to 15.0% and Si: 0.1 to 1.5% and optional alloying of at least one of the rare earth elements Y, La, Ce, or the elements Hf, Sr and Zr.

[0023] According to yet another preferred embodiment of the invention, it is provided that the at least one component produced by means of additive manufacturing is a component of the metal component which is resistant to high-temperature corrosion and / or high-temperature abrasion and which is produced by means of laser powder deposition welding (e.g. extreme high-speed laser deposition welding EHLA), selective laser sintering (e.g. binder jetting) or by means of a selective laser melting process (e.g. SLM powder bed process).

[0024] It is further advantageously provided that the metal component (a) has a functional element which is fastened to or in the component resistant to high-temperature corrosion and / or high-temperature abrasion by pressing on or pressing in and / or (b) has a functional structure which is formed by the component resistant to high-temperature corrosion and / or high-temperature abrasion.

[0025] The functional element can, for example, be a sensor or a component-integrated, printed, freely movable functional element, such as a fan wheel, a flap or a valve.

[0026] The additional structure could, for example, be a component-integrated, printed sensor housing. Other possible functional structures include component-integrated near-surface cooling or a component-integrated surface structure for laminar (shark surface) or turbulent gas / air flow control, which are / are printed accordingly.

[0027] In the method according to the invention for producing the aforementioned metal component, it is provided that the at least one component of the metal component that is resistant to high-temperature corrosion and / or high-temperature abrasion is produced by means of additive manufacturing. The advantages mentioned above in connection with the metal component also apply accordingly to the method.

[0028] Optionally, after the construction of the at least one component of the metal component that is resistant to high-temperature corrosion and / or high-temperature abrasion, a heat treatment of the metal component or at least a part of the metal component comprising the at least one said component is carried out.

[0029] The material for additive manufacturing is provided in particular in the form of a powder for plasma or water atomization or a solid or flux-cored wire.

[0030] In the process, the metal component or its component resistant to high-temperature corrosion and / or high-temperature abrasion is preferably produced as follows: (a) by laser powder deposition welding (e.g., extreme high-speed laser deposition welding EHLA), (b) by selective laser sintering (e.g., binder jetting) or (c) by selective laser melting (e.g., SLM powder bed process).

[0031] A metal powder-based additive manufacturing process involves the following steps in particular: (i) Providing 3D data for layer-by-layer production of the corresponding additively manufactured component of the metal component, (ii) providing a base which in particular forms a further component of the metal part, (iii) applying a layer of a corresponding metal powder to the substrate, (iv) melting or sintering the metal powder layer based on the 3D data using a laser device to build up the component layer by layer, (v) Moving the substrate to apply the next layer of metal powder, (vi) Repeating the steps of applying a layer of metal powder, melting or sintering this layer of metal powder based on the 3D data and moving the substrate to apply the next layer of metal powder until the component of the metal component to be additively manufactured is completely built up layer by layer according to the 3D data.

[0032] The component of the metal component to be manufactured additively is, of course, primarily the component of the metal component that is resistant to high-temperature corrosion and / or high-temperature abrasion. In the case of an additively manufactured hybrid pressure component, this also includes the other component created using additive manufacturing from the steel with the other steel alloy.

[0033] In the following, some important aspects of the additive manufacturing methods preferred here will be described again in other words: Production is usually carried out undersize and by complete or local printing with the aforementioned ACroMaSt alloy.

[0034] With a view to achieving a high deposition rate, the AlCroMaSt alloy could be supplied in the form of welding wire and melted (printed).

[0035] However, when using powders, particularly fine or complex structures can be created on the inner surface, which, for example, manipulate the flow (direct or channel) or enable additional component-integrated cooling.

[0036] Optionally, additional surface finishing is also conceivable, for example through an appropriate coating.

[0037] The invention will be explained below by way of example with reference to the accompanying drawings using preferred embodiments, wherein the features presented below can represent an aspect of the invention both individually and in combination. They show: Fig. 1 a tuyere of a blast furnace with a metal component designed as an injection lance according to a preferred embodiment of the invention in a sectional view and Fig. 2 a diagram created during wear tests, in which high-temperature abrasion for different steel alloys is plotted over time.

[0038] The Fig. 1 shows a sectional view of a tuyere 10 of a tuyere ring in a refractory lining 12 of a blast furnace. The tuyere 10 extends along a longitudinal axis 14 and is tapered to form a conical shape, resulting in a corresponding interior space 16 of this tuyere 10. A nozzle tip 18 of a nozzle block opens into the tuyere 10 with its pointed end 20. The nozzle tip 18 also extends along a longitudinal axis 22 and is tapered to form a conical shape towards the pointed end 20, resulting in a corresponding interior space, i.e., the interior space 24 of the nozzle tip 18. The longitudinal axes 14, 22 of the tuyere 10 and the nozzle tip 18 are essentially coaxial.

[0039] A channel 28 is formed in a nozzle wall 26 of the nozzle tip 18, which channel extends along an imaginary axis 30 from the interior space 24 at the pointed end 20 of the nozzle tip 18 to an exterior space of the nozzle tip 18. The axis 30 of the channel 28 and the longitudinal axis 22 of the nozzle tip 18 form an acute angle α. For this acute angle α, in particular, 10° ≤ α ≤ 30° applies. An end region 32 of a metal component 36 designed as an injection lance 34 extends through this channel 28 into the interior space 24 of the nozzle tip 18 - in the present case even into the interior space 16 of the tuyere 10. Fuel is injected into the tuyere 10 via this tubular metal component 36, i.e. the injection lance 34. The tip of the end region 32 of the injection lance 34 / the metal component 36 is exposed to the abrasive forces of particles in the hot air coming from the nozzle tip 18 or the corresponding blast furnace process gases.

[0040] The tubular metal component 36, which forms the injection lance 34, has a steel base tube 38. This base tube 38 is a base element 40 of the metal component 36. Furthermore, the tubular metal component 36 has, at least in its end region 32, a component 42 made of an AlCroMaSt alloy that is resistant to high-temperature corrosion and / or high-temperature abrasion and completely encloses the base element 40 in the end region 32. This component 42 of the metal component 36, which is resistant to high-temperature corrosion and / or high-temperature abrasion, is a component 42 created by additive manufacturing. The additive manufacturing process used to produce this component is, for example, a laser powder deposition process.

[0041] This example shows the Fig. 1 essentially consists of two components 42, 44, namely the component 42 which is resistant to high-temperature corrosion and / or high-temperature abrasion and the base element 40 designed as a base tube 38 as a further component 44. The component 42 made of the AlCroMaSt alloy which is resistant to high-temperature corrosion and / or high-temperature abrasion is significantly more resistant than the steel of the further component 44 and therefore serves as a protective element 46.

[0042] The shape of the high-temperature corrosion and / or high-temperature abrasion-resistant component 42 is roughly the shape of a protective sheath / protective tube that circumferentially surrounds the further component 44 of the tubular metal component 36, designed as the base tube 38—at least in the end region 32. However, the shape of the high-temperature corrosion and / or high-temperature abrasion-resistant component 42 results from the specific wear and flow requirements of the specific application and is not shown in detail here. For example, grooves, etc., that serve as functional structures for flow guidance (flow guidance structures) are conceivable.

[0043] The Fig.Figure 2 shows a graph created during wear tests, in which high-temperature abrasion for various steel alloys is plotted over time. The graph (with measurement points and linear trend lines through the zero point) illustrates the respective wear at 750 °C. The high-temperature abrasion is shown in mg over the test duration t in minutes.

[0044] To simulate the transport of particles in hot air under extreme conditions, quartz sand (grain size 50 µm) was chosen as the abrasive. The speed and angle represent a more stringent operating condition, allowing the laboratory test to obtain meaningful wear resistance results even at a shorter duration than the actual operating time.

[0045] Evidence of good wear resistance at temperatures significantly above room temperature was demonstrated in a laboratory test for specimens with three different chemical compositions, all within the limits of the chemical composition of the AlCroMaSt alloy defined above (filled symbols: circle, diamond, triangle). As a reference, a nickel-based alloy ("Alloy C22") was tested under the same test conditions (open circles).

[0046] The material removal of the nickel-based alloy (reference - open circles), which is typically used for exposure to acids and alkalis, exhibits similar wear behavior for short exposure times (30 min.) to that of the inventive samples (filled symbols: circle, diamond, triangle). After longer exposure times (120 min.), the material removal due to abrasion for the AlCroMaSt alloys is significantly lower than that of the reference, in some cases only 50%. List of reference symbols 10 Wind shape 12 Brick lining 14 Longitudinal axis (wind shape) 16 Interior (wind form) 18 nozzle tip 20 End 22 Longitudinal axis (nozzle tip) 24 Interior (nozzle tip) 26 Nozzle wall 28 channel 30 axis 32 End area 34 injection lance 36 metal component 38 base pipe 40 basic element 42 component 44 additional component 46 protective element α acute angle

Claims

[1] Metal component (36) made of or with at least one component (42) resistant to high-temperature corrosion and / or high-temperature abrasion, which consists of a steel alloy with the following chemical composition in weight percent: C: 0.01 to 1.0, Al: 3.0 to 12.0, Cr: 1.0 to 15.0, Mn: 5.0 to 30.0 and Si: 0.1 to 4.0, The remainder is iron and impurities resulting from the melting process, optionally supplemented by one or more of the following elements with the corresponding proportion in weight % of the composition: Cu: 0.001 to 1.5, Ni: 0.001 to 5.0, S: 0.001 to 0.010, N: 0.001 to 0.010, B: 0.00005 to 0.0250, Ti: 0.01 to 1.0, V: 0.01 to 1.0, Nb: 0.01 to 1.0, Y: 0.001 to 0.1, La: 0.001 to 0.1, Ce: 0.001 to 0.1, Hf: 0.001 to 0.1, Sr: 0.001 to 0.1 and Zr: 0.001 to 0.1, characterized by that the at least one component (42) of the metal component (36) which is resistant to high-temperature corrosion and / or high-temperature abrasion is a component (42) produced by means of additive manufacturing. [2] Metal component according to claim 1, characterized by a further component (44) made of metal, in particular of steel, which is preferably designed as a base element (40) and on which the at least one component (42) resistant to high-temperature corrosion and / or high-temperature abrasion is arranged. [3] Metal component according to claim 2, characterized by that the at least one component (42) resistant to high-temperature corrosion and / or high-temperature abrasion forms a protective element (46), in particular a protective sheath, for at least part of the surface of the base element (40). [4] Metal component according to claim 3, characterized bythat at least one part of the surface of the base element (40) covered by the protective element (46) or one of the protective elements is an end region (32) of the base element (40). [5] Metal component according to claim 1, characterized by that this metal component (36) is an additively manufactured hybrid pressure component which, in addition to the at least one component (42) resistant to high-temperature corrosion and / or high-temperature abrasion, has at least one other component produced by additive manufacturing from a steel with a different steel alloy. [6] Metal component according to at least one of claims 1 to 5, characterized by that the metal component (42) is an injection lance (34) for injecting fuel into a tuyere (10) of a blast furnace. [7] Metal component according to at least one of claims 1 to 6, characterized bythat this metal component (36) is a high-temperature metal component (36) for use at temperatures above 300°C, preferably above 800°C. [8] Metal component according to at least one of claims 1 to 7, characterized by that the at least one component (42) produced by additive manufacturing is a component (42) of the metal component (36) produced by laser powder deposition welding and resistant to high-temperature corrosion and / or high-temperature abrasion. [9] Metal component according to at least one of claims 1 to 8, characterized by - a functional element which is attached to or in the component (42) resistant to high-temperature corrosion and / or high-temperature abrasion by pressing or pressing in and / or - a functional structure formed by the high-temperature corrosion and / or high-temperature abrasion-resistant component (42). [10] Method for producing a metal component (36) according to one of claims 1 to 9, characterized by that the at least one component (42) of the metal component which is resistant to high-temperature corrosion and / or high-temperature abrasion is produced by means of additive manufacturing. [11] Method according to claim 10, characterized by that the material for additive manufacturing is provided in the form of a powder for plasma or water atomization or a solid or cored wire. [12] Method according to claim 10 or 11, characterized by that the additive manufacturing process is a laser powder deposition welding process, a selective laser sintering process or a selective laser melting process.

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