The use of nickel-iron-chromium alloy, which offers high resistance in highly corrosive environments, along with good workability and strength.

Abstract

A powder of nickel-iron-chromium alloy having excellent high-temperature corrosion resistance, the powder being composed of spherical particles having a size of 5 to 250 μm, the alloy being composed of (by mass%): 35.0 to 38% nickel, 26.0 to 30.0% chromium, more than 0.7 to 1.50% silicon, 0.40 to 1.30% aluminum, 0.00 to 1.0% manganese, 0.0001 to 0.05% magnesium, 0.015-0.12% Ca, 0.001-0.150% Nitrogen, 0.001-0.030% Phosphorus, 0.0001-0.100% Oxygen, Max. 0.010% Sulfur, Less than 1.0% Molybdenum, Less than 1.0% Cobalt, Less than 0.5% Copper, Less than 1.0% Tungsten, Balance Iron, and Normal Process Impurities, with the following relationship: Fc=-1.2+0.29×Ni-4.6×Si-4.4×Al≦2.5 (1a) must be satisfied, where Ni, Si and Al are the concentrations in mass % of the corresponding elements.

Description

[Technical Field]

[0001] This invention relates to the use of a nickel-iron-chromium alloy that has good high-temperature corrosion resistance in highly corrosive environments, as well as good workability and strength. [Background technology]

[0002] Austenitic nickel-iron-chromium alloys with varying nickel, chromium, and iron content have long been used in furnace structures and in the chemical and petrochemical industries. These applications require good high-temperature corrosion resistance and good heat resistance, even in highly corrosive environments such as carburizing, sulfidation, and chlorination.

[0003] Generally, it should be noted that the high-temperature corrosion resistance of the alloys shown in Table 1 improves with increasing chromium content. All of these alloys form a chromium oxide layer (Cr2O3) with a more or less closed silicon oxide layer beneath it. Adding small amounts of oxygen-affinity elements, such as yttrium or cerium, improves corrosion resistance. Chromium content is slowly consumed as it builds a protective layer during use in the application area. Therefore, a higher chromium content extends the material's lifespan because a higher chromium content in the elements forming the protective layer delays the point at which the chromium content falls below a critical value and oxides other than Cr2O3 (e.g., iron-containing and nickel-containing oxides) are formed. Further improvements in high-temperature corrosion resistance are achieved by adding silicon or aluminum. Beyond certain minimum content levels, these elements form a closed layer beneath the chromium oxide layer, thus reducing chromium consumption.

[0004] In a carburizing environment (a mixture of CO, H2, CH4, CO2, and H2O), carbon can penetrate the material, potentially leading to the formation of internal carbides. This results in a loss of notched impact strength. A chromium deficiency in the matrix can also trigger this transformation process.

[0005] High resistance to carburizing is achieved by materials with low carbon solubility and low carbon diffusion rates. Therefore, nickel alloys are generally more resistant to carburizing than iron-based alloys because both carbon diffusion and carbon solubility are lower in nickel than in iron. Increasing the chromium content results in higher carburizing resistance by forming a chromium oxide protective layer, provided that the partial pressure of oxygen in the gas is sufficient for its formation. At very low oxygen partial pressures, materials can be used that form layers from silicon oxide or the even more stable aluminum oxide, both of which can form protective oxide layers even at significantly lower oxygen content.

[0006] In carburizing and sulfiding environments with low oxygen partial pressure (CO, H2, H2O, CO2, H2S mixtures), sulfur can penetrate the material, leading to the formation of sulfides. The melting point may also drop to very low values ​​(635°C for Ni-Ni3S2 eutectic mixtures and 988°C for Fe-FeS eutectic mixtures). In sulfiding environments, nickel-iron-chromium alloys with a high nickel content are often more sensitive than nickel-iron-chromium alloys with a high iron content. Here again, the addition of silicon or aluminum can further improve high-temperature corrosion resistance.

[0007] In chlorinated environments with low oxygen partial pressure, volatile metal chlorides with high vapor pressure and / or low melting points can form, leading to high corrosion rates. High concentrations of chromium and / or nickel improve corrosion resistance.

[0008] German Patent No. DE4130139 (DE 41 30 139 C1) describes a heat-resistant, hot-formable austenitic nickel alloy comprising (by mass%) 0.05–0.15% carbon, 2.5–3.0% silicon, 0.2–0.5% manganese, up to 0.015% phosphorus, up to 0.005% sulfur, 25–30% chromium, 20–27% iron, 0.05–0.15% aluminum, 0.001–0.005% calcium, 0.05–0.15% rare earth elements, 0.05–0.20% nitrogen, the remainder being nickel and impurities resulting from normal melting.

[0009] The alloy described in German Patent No. DE4130139 is known by the names "NiCr28FeSiCe", Alloy 45TM, Nicrofer 45TM, or material number 2.4889, and will be referred to as "45TM" below.

[0010] Alloy 45TM is highly resistant to carburizing and sulfiding media, making it suitable for use in waste incineration or coal gasification facilities. Figure 1 shows the metallographically measured corrosion attack depth of various alloys as a function of temperature after 2100 hours of aging in H2S-containing gas at the PRENFLO coal gasification pilot plant in Fürstenhausen. Table 1 shows the compositions of alloys investigated using the prior art. High chromium and silicon content significantly reduces corrosion attack depth. A silicon content of 2.5% or more allows for the formation of a silicon oxide layer beneath the chromium oxide protective layer, resulting in high corrosion resistance of the material. 45TM with 26-29% chromium and 2.5-3% silicon exhibits the lowest corrosion attack depth at all temperatures, followed by AC66 with 26-28% chromium and up to 0.3% silicon.

[0011] However, alloy 45TM is extremely difficult to process. This is demonstrated, for example, by the formation of cracks during hot forming. 45TM also tends to crack during welding, which makes intrinsic welding (using filler material within the composition range of the materials being welded), which is reasonable for corrosion protection reasons, impossible and makes the material difficult to use in practice. Reasons for the increased high-temperature cracking of austenitic FeCrNi weld metals with primary austenite solidification include the formation of a low-molten phase due to silicon concentration at austenite grain boundaries (eutectic mixture Fe-Fe2Si: 1212°C, eutectic mixture NiSi-Ni3Si2: 964°C, and NiSi: 996°C), as well as the increased solidification range.

[0012] In contrast, alloy AC66 (see Table 1 for composition) has sufficient weldability and workability, but as shown in Figure 1, it does not have very good corrosion resistance in coal gasification equipment.

[0013] When carburizing and sulfidation conditions are combined with chlorine attack, as occurs in coal gasification and waste incineration facilities, the material requirements become even more stringent.

[0014] For materials that can be used in carburized, sulfurized, and chlorinated environments, especially under certain atmospheric conditions, compromises must be made regarding their composition.

[0015] Heat resistance is improved particularly by a high carbon content. However, high concentrations of solid solution strengthening elements, such as chromium, aluminum, silicon, molybdenum, and tungsten, also improve heat resistance.

[0016] U.S. Patent No. 6,623,869 B1 describes a metallic material comprising, by weight: up to 0.2% carbon, 0.01 - 4% silicon, 0.05 - 2% manganese, up to 0.04% phosphorus, up to 0.015% sulfur, 10 - 35% chromium, 30 - 78% nickel, aluminum of 0.005% or more but less than 4.5%, 0.005 - 0.2% nitrogen, and one or both of 0.015 - 3% copper and 0.015 - 3% cobalt, with the balance being essentially iron. At this time, the value of 40Si + Ni + 5Al + 40N + 10(Cu + Co) is 50 or more, where the elemental symbols in the formula represent the alloy content of the respective elements. Since the metallic material has excellent corrosion resistance in an environment where metal dusting can occur, it can be used in furnace tubes, piping systems, heat exchanger tubes, etc. in oil refineries or petrochemical facilities. It can significantly improve the durability and safety of the equipment.

[0017] U.S. Patent No. 3,833,358 A describes a refractory iron-based alloy that provides high resistance to creep, thermal shock, thermal fatigue, and grain boundary oxidation, as well as good weldability, consisting essentially of (by weight percentage) the following elements: C 0.05 - 0.20 Ni 30 - 40 Cr 20 - 30 Nb 0.2 - 2 N 0.04 - 0.2 Mn 0.6 - 2[[ID=

[17] ] Si 0.6 - 2 Ta 0 - 0.3 Ti 0 - 1 Mo 0 - 0.5 Al 0 - 0.05 Pb 0 - 0.01 Sn 0 - 0.01 Zn 0 - 0.01 Cu 0 - 0.25 and the balance being essentially iron, describes the above alloy. At this time, the weight percentages of the above elements satisfy the following formula: 30×C%+Ni%+0.5×Mn%+16×N%=Cr%+0.5×(Nb+1 / 2Ta)%+3.5×Ti%+1.5×Si%+Mo%+(11±2)% A = B ± 20% Here, A = 30 × C%, B = 2 × Ti% + 6 × (Nb + 1 / 2Ta)%.

[0018] U.S. Patent No. 3,865,581 A describes hot-formable heat-resistant alloys having 0.01–0.5% C, 0.01–2.0% Si, 0.01–3.0% Mn, 22–80% Ni, and 10–40% Cr as the main components, and also containing 0.0005–0.20% B and 0.001–6.0% Zr, or both, and further one or more of 0.001–0.5% Ce, 0.001–0.2% Mg, and 0.001–1.0% Be, with the remainder being iron and unavoidable impurities. They are suitable for use in furnace structures (such as burner tips, protective housings, and protective tubes for thermocouples).

[0019] German Patent No. 1024719 (DE 1024719 A) describes a method for adding cerium and / or lanthanum to a nickel-iron alloy. It is a hot-formable alloy characterized by the following composition: 0-0.5% carbon, 10-60% one or more elements of chromium, molybdenum, and tungsten (each of which is not more than 30%), 0-73% iron, 0.02-1.10% cerium or lanthanum or both, and the remainder 4-70% nickel (including impurities), provided that the content of the rare earth metals is combined with the nickel content as follows: Nickel % Cerium or lanthanum or both % 4 Approx. 0.02~1.10 10 Approx. 0.02~1.05 20 Approximately 0.02~0.90 30 Approx. 0.02~0.75 40 Approx. 0.02~0.60 50 approx. 0.02~0.45 60 approx. 0.02~0.30 70 Approximately 0.02~0.15.

[0020] European Patent Application Publication No. 0812926 (EP 0 812 926 A1) describes a nickel-based alloy comprising 0.06–0.14% carbon, 35–46% nickel, 22.5–26.5% chromium, 0–1.5% manganese, 0.5–2% silicon, 0.1–1% titanium, 0.05–2% aluminum, 1–3% molybdenum, 0.2% niobium, 0.1–1% tantalum, 0–0.3% tungsten, 0–0.008% boron, 0–0.05% zirconium, and the remainder iron, and incidental impurities, which is strengthened under use.

[0021] International Publication No. 2007 / 124996 (WO 2007 / 124996 A1) describes a reaction vessel for use in the production of hydrogen sulfide by the reaction of sulfur and hydrogen, wherein the reaction vessel and, optionally, connecting lines, as well as accessories and measuring and control mechanisms, are made of an aluminum-containing material that is partially or completely resistant to the reaction mixture. In particular, the material contains components of 0-0.3% C, 0-2.5% Si, 0-2.5% Mn, 0-0.1% P, 0-0.3% S, 15.0-28.0% Cr, 0-1.0% Cu, 0-5% Fe, 1.0-2.5% Al, 0-2.5% Co, 0-1.5% Ti, 0-0.4% Y, and up to 70% Ni (% is by mass%).

[0022] German Patent Application Publication No. 102007005605 (DE 10 2007 005 605 A1) describes an iron-nickel-chromium-silicon alloy having (by mass%) 34-42% nickel, 18-26% chromium, 1.0-2.5% silicon, and additives of 0.05-1% Al, 0.01-1% Mn, 0.01-0.26% lanthanum, 0.0005-0.05% magnesium, 0.01-0.14% carbon, 0.01-0.14% nitrogen, up to 0.01% sulfur, up to 0.005% boron, the remainder being iron, and impurities of the usual process. This alloy is used in heating elements.

[0023] U.S. Patent No. 5021215 (US 5,021,215 A) describes a high-strength, heat-resistant steel with improved formability, which is essentially (by mass%) C: 0.05~0.30%, Si: 3.0% or less, Mn: 10% or less, Cr: 15~35%, Ni: 15~50%, Mg: 0.001~0.02%, B: 0.001~0.01%, Zr: 0.001~0.10%, Ti: 0.05~1.0%, Nb: 0.1~2.0%, and at least one element, Al: 0.05~1.0%, Mo: 0-3.0%, W: 0-6.0%, (Mo+1 / 2W=3.0% or less) The present invention discloses a steel comprising the remainder Fe and incidental impurities, wherein the oxygen and nitrogen impurities are limited to 50 ppm or less or 200 ppm or less, and the austenite grain size number is limited to No. 4 or higher.

[0024] Japanese Patent Publication No. 56-163244 (JPS 56163244 A) describes the improvement of the hot workability and oxidation resistance of austenitic steel by adding specific amounts of C, Si, Mn, Ni, Cr, Al, B, rare earth elements, and Ca to steel. This is achieved by austenitic steel having the following composition in mass%, in mass%,: <0.2% C, 1.5-3.5% Si, <2% Mn, 8-35% Ni, 15-30% Cr, <2% Al, 0.0005-0.005% B, 0.005-0.1% rare earth elements, and 0.0005-0.02% Ca, or optionally with an additional 0.0005-0.03% Mg added. The austenitic steel obtained from this process is smelted in a conventional steelmaking furnace, the molten steel is formed into billets, and then hot-rolled.

[0025] U.S. Patent No. 7,118,636 (US 7,118,636 B2) describes a nickel-iron-chromium alloy containing a solidified phase that can maintain its microstructure at high temperatures during forging and processing of the alloy. The alloy contains sufficient amounts of titanium, zirconium, carbon, and nitrogen so that fine titanium nitride and zirconium nitride are formed even when they are near the solid solution limit in the molten state of the alloy. When articles are manufactured from such alloys through thermal processing, dispersion of fine titanium carbonitride and zirconium carbonitride precipitates occurs during the solidification of the molten material, and these precipitates remain in the alloy during subsequent processing steps (at high temperatures), hindering austenite grain growth. The nickel-iron-chromium alloy contains less than 0.05% by mass of niobium, at least 0.05% of zirconium, at least 0.05% of carbon, at least 0.05% of nitrogen (the mass ratio of carbon to nitrogen is at least 1:2 to less than 1:1), sufficient titanium, zirconium and / or aluminum to be chromium carbide-free, and sufficient amounts of titanium, zirconium, carbon and nitrogen to form a uniform dispersion of fine titanium carbonitride and zirconium carbonitride, and sufficient amounts of [(Ti x Zr 1-x )(C y N 1-y This nickel-iron-chromium alloy further consists of approximately 32% to 38% by mass of iron, approximately 22% to 28% by mass of chromium, approximately 0.10% to 0.60% of titanium, approximately 0.05% to 0.30% of zirconium, approximately 0.05% to 0.30% of carbon, approximately 0.05% to 0.30% of nitrogen, approximately 0.05% to 0.5% of aluminum, up to 0.99% of molybdenum, up to 0.01% of boron, up to 1% of silicon, up to 1% of manganese, the remainder being nickel, and incidental impurities.

[0026] Japanese Patent Publication No. 57-134544 (JPS 57134544 A) describes the improvement of resistance to stress corrosion cracking of oil well pipes by adding specific amounts of Mo, W, etc. to high Cr-Ni content steel as a pipe material. For this purpose, the composition is <0.10% C, <1.0% Si, <2.0% Mn, <0.030% P, <0.005% S, <0.5% Al, 22.5-30% Cr, 25-60% Ni and Mo and / or W, and the formula Cr(%) + 10 × Mo(%) + 5 × W(%) ≥ 70% 4% ≤ Mo(%) + 1 / 2W(%) < 8% Alloy steel that satisfies the following conditions is used. The steel is used for oil well tubing used in highly corrosive and harsh environments such as oil wells and natural gas wells. The alloy may contain <1% Cu and / or <2% Co and / or <0.10% of one or more rare earth elements, <0.20% Y, <0.10% Mg, <0.10% Ca, and <0.5% Ti. Oil well tubing with excellent resistance to stress corrosion cracking can be manufactured in the highly corrosive environment of oil wells containing H2S, CO2, and Cl. [Prior art documents] [Patent Documents]

[0027] [Patent Document 1] German Patent No. DE4130139 [Patent Document 2] U.S. Patent No. 6623869 [Patent Document 3] U.S. Patent No. 3833358 [Patent Document 4] German Patent No. 1024719 [Patent Document 5] European Patent Application Publication No. 0812926 [Patent Document 6] International Publication No. 2007 / 124996 [Patent Document 7] German Patent Application Publication No. 102007005605 Specification [Patent Document 8] U.S. Patent No. 5021215 [Patent Document 9] Japanese Patent Application Publication No. 56-163244 [Patent Document 10] U.S. Patent No. 7,118,636 [Patent Document 11] Japanese Patent Publication No. 57-134544 [Overview of the Initiative] [Problems that the invention aims to solve]

[0028] Therefore, the problem that forms the basis of the present invention is, a) In highly corrosive environments, such as carburizing, sulfiding, and chlorinating environments, it exhibits good high-temperature corrosion resistance comparable to alloy 45TM. b) To have sufficient workability, especially weldability, similar to alloy AC66 as much as possible, and c) Similar to alloy AC66, it has sufficient heat resistance at 500°C. The idea is to consider using a nickel-iron-chromium alloy. [Means for solving the problem]

[0029] The problem underlying this invention is the use of a nickel-iron-chromium alloy as a powder having excellent high-temperature corrosion resistance, wherein the powder consists of spherical particles with a size of 5 to 250 μm, and this alloy is (by mass%) 35.0-38% nickel, 26.0-30.0% chromium, Silicon content of over 0.7% to 1.50%, 0.40-1.30% aluminum, 0.00~1.0% manganese, Each contains 0.0001 to 0.05% magnesium and / or calcium, 0.015~0.12% carbon, 0.001-0.150% nitrogen, 0.001-0.030% phosphorus, 0.0001 to 0.100% oxygen, Maximum 0.010% sulfur, Molybdenum less than 1.0%, less than 1.0% cobalt, Less than 0.5% copper, Tungsten less than 1.0%, The remainder is iron, and impurities resulting from the normal process. It contains the following relationship: Fc=-1.2+0.29×Ni-4.6×Si-4.4×Al≦2.5 (1a) The following must be satisfied, where Ni, Si, and Al are the mass percent concentrations of the respective elements. This is resolved by the aforementioned use.

[0030] Further advantageous aspects of the subject matter of the present invention can be obtained from the related dependent claims.

[0031] The nickel content is 35.0-38.0%, and the preferred content can be adjusted within the following range: • 35 or >35.0~<38.0% • 35 or >35.0% to 37 or <37.0%.

[0032] The chromium content ranges from 26.0% to 30.0%, and the preferred range can be adjusted as follows: • >26.0~<30.0% • 27.0 or >27.0~30.0 or <30.0% 28.0% or >28.0-30.0% or <30.0%.

[0033] The silicon content is >0.70 to 1.50%. Preferably, the silicon content in the alloy can be adjusted within the following ranges: • >0.70~<1.50% • 0.80 or >0.80~1.50 or <1.50% • 0.90 or >0.90~1.50 or <1.50% • 0.80 or >0.80~1.50 or <1.50% • 0.80 or >0.80~1.45 or <1.45%.

[0034] The aluminum content is 0.40 to 1.30%, and here again, the aluminum content can preferably be adjusted as shown below: • >0.40~<1.30% • 0.50 or >0.50~1.30 or <1.30% • 0.50 or >0.50~1.20 or <1.20% • 0.50 or >0.50~1.10 or <1.10% • 0.60 or >0.60~1.10 or <1.10%.

[0035] The same applies to manganese, which can be present in alloys at concentrations of 0.0–1.0%. Alternatively, the following ranges are also possible: • >0.0~<1.00% • >0.0 to 0.50 or <0.50% >0.0 to 0.05 or <0.05% • 0.005 or >0.005 to 0.20 or <0.20% • 0.005 or >0.005 to 0.10 or <0.10%.

[0036] Magnesium and / or calcium are also present in concentrations of 0.0001 to 0.05%. Preferably, these elements may be adjusted in the alloy as follows: • 0.0001~0.030% • 0.0001~0.020% • 0.0002~0.015% 0.0010~0.010%.

[0037] The alloy contains 0.015 to 0.12% carbon. Preferably, this can be adjusted within the following ranges in the alloy: • >0.015~<0.12% • 0.03 or >0.03 to 0.10 or <0.10% • 0.04 or >0.04~0.10 or <0.10% • 0.05 or >0.05~0.10 or <0.10% • 0.05 or >0.05~0.09 or <0.09%.

[0038] This also applies to nitrogen elements present in concentrations of 0.001 to 0.150%. Preferred concentrations can be expressed as follows: • >0.001~<0.150% • 0.010 or >0.010 to 0.140 or <0.140% • 0.020 or >0.020~0.140 or <0.140% • 0.050 or >0.050~0.140 or <0.140%.

[0039] The alloy further contains phosphorus at a content of 0.001 to 0.030%. Preferred content can be shown as follows: 0.001-0.015%.

[0040] The alloy also contains oxygen at a concentration of 0.0001 to 0.100%.

[0041] Sulfur is present in the alloy at a maximum of 0.010%. Preferred content may be as follows: • Sulfur: Maximum 0.008%.

[0042] Molybdenum is present in the alloy at a concentration of less than 1.0%. The molybdenum content may be further limited as follows: • Mo up to 0.50% or <0.50% • Mo up to 0.20% or <0.20% • Mo up to 0.10% or <0.10% • Mo up to 0.05% or <0.05% • Mo: Maximum 0.02% or <0.02%.

[0043] Furthermore, the alloy contains less than 1.0% cobalt. The cobalt content can be further limited as follows: • Co up to 0.50% or <0.50% • Co up to 0.20% or <0.20% • Co up to 0.10% or <0.10% • Co up to 0.05% or <0.05% • Co is a maximum of 0.015% or <0.015%.

[0044] Furthermore, the alloy may contain less than 0.5% copper. The copper content may be further limited as follows: • Cu up to 0.30% or <0.30% • Cu up to 0.10% or <0.10% • Cu up to 0.05% or <0.05% • Cu: Maximum 0.015% or <0.015%.

[0045] Tungsten is present in alloys at a maximum content of 1.0%. The tungsten content can be further limited as follows: • W <1.0% • W up to 0.50 or <0.50% • W up to 0.20 or <0.20% • W up to 0.10 or <0.10% • W up to 0.05 or <0.05% • W is a maximum of 0.02% or <0.02%.

[0046] The remainder of the alloy consists of iron and impurities resulting from the usual processes. The iron content can be further limited as follows: • 28.0% or >28.0-38.0% • 29.0% or >29.0-38.0% • 30.0% or >30.0-38.0% or <38.0%.

[0047] To exhibit sufficient resistance under carburizing, sulfidation, and chlorination environments, the following relationship exists between nickel, silicon, and aluminum: Fc=-1.2+0.29×Ni-4.6×Si-4.4×Al≦2.5 (1a) The following conditions must be met, where Ni, Si, and Al are the mass percent concentrations of the respective elements.

[0048] The preferred range is, Fc=-1.2+0.29×Ni-4.6×Si-4.4×Al≦1.5 (1b) Fc=-1.2+0.29×Ni-4.6×Si-4.4×Al≦1.0 (1c) It can be adjusted.

[0049] The addition of oxygen-affinity elements, such as cerium, lanthanum, yttrium, and hafnium, improves corrosion resistance. This is achieved by their incorporation into the oxide layer, where they block the diffusion pathway of oxygen at the grain boundaries.

[0050] If necessary, the alloy may contain 0.001 to 0.20% of one or more of the following elements: cerium, lanthanum, yttrium, zirconium, and hafnium, where the formula is as follows: FRE=0.714×Ce+0.720×La+1.124×Y+1.096×Zr+0.560×Hf≦0.10 (2a) The following conditions must be met, where Ce, La, Y, Zr, and Hf are the mass percent concentrations of the respective elements.

[0051] Preferably, if at least one of the elements cerium, lanthanum, yttrium, zirconium, and hafnium is present, FRE can be adjusted as follows: FRE=0.714×Ce+0.720×La+1.124×Y+1.096×Zr+0.560×Hf≦0.075 (2b) FRE=0.714×Ce+0.720×La+1.124×Y+1.096×Zr+0.560×Hf≦0.065 (2c).

[0052] Selectively, when cerium and lanthanum are present together, cerium mischmetal (CeMM) can also be used at a concentration of 0.001-0.20%, where FRE is as follows: FRE=0.716×CeMM+1.124×Y+1.096×Zr+0.560×Hf≦0.10 (3a) The formula must be changed as follows, where CeMM, Y, Zr, and Hf are the mass percent concentrations of the respective elements.

[0053] Preferably, when cerium mischmetal is added, the FRE can be adjusted as follows: FRE=0.716×CeMM+1.124×Y+1.096×Zr+0.560×Hf≦0.075 (3b) FRE=0.716×CeMM+1.124×Y+1.096×Zr+0.560×Hf≦0.065 (3c).

[0054] Preferably, cerium, lanthanum, cerium mischmetal, zirconium, and hafnium may be included in the alloy within the following ranges: • >0.001~<0.20% • 0.001 or >0.001 to 0.15 or <0.15% • 0.001 or >0.001 to 0.10 or <0.10% • 0.001 or >0.001 to 0.08 or <0.08% • 0.001 or >0.001 to 0.05 or <0.05% • 0.001 or >0.001 to 0.04 or <0.04% • 0.01 or >0.01~0.04 or <0.04%.

[0055] Preferably, yttrium can be contained in the alloy within the following ranges: • >0.001~<0.20% • 0.001 or >0.001 to 0.15 or <0.15% • 0.001 or >0.001 to 0.10 or <0.10% • 0.001 or >0.001 to 0.08 or <0.08% • 0.01 or >0.01 to 0.08 or <0.08% • 0.01 or >0.01 to <0.045%.

[0056] Selectively, titanium can be present in the alloy at a content of 0.0 to 0.50%. Preferably, titanium can be contained in the alloy within the following ranges: • >0.0~<0.50% • >0.0 to 0.50 or <0.50% • 0.001 or >0.001 to 0.20 or <0.20% • 0.001 or >0.001 to 0.15 or <0.15% • 0.001 or >0.001 to 0.10 or <0.10% • 0.001 or >0.001 to 0.05 or <0.05% • 0.001 or >0.001 to 0.04 or <0.04% • 0.005 or >0.005 to 0.20 or <0.20% • 0.010 or >0.010~0.20 or <0.20%.

[0057] Selectively, the niobium element in the alloy can be adjusted to a content of 0.0 to 0.2%. Preferably, niobium can be contained in the alloy within the following ranges: • >0.0~<0.20% • >0.0~0.15 or <0.15% >0.0~0.10 or <0.10% >0.0 to 0.05 or <0.05% • >0.0~0.02 or <0.02% • 0.001 or >0.001 to 0.20 or <0.20% • 0.010 or >0.010~0.20 or <0.20%.

[0058] Selectively, 0.0–0.20% tantalum may also be included in the alloy. Preferred concentrations may be shown as follows: • >0.0~<0.20% >0.0~0.10 or <0.10% • >0.0 to 0.05 or <0.05%.

[0059] Selectively, boron can be included in the alloy at a content of 0.0001 to 0.008%. Preferred content can be shown as follows: • Boron 0.0005~0.008% • Boron 0.0005~0.005% • Boron 0.0005~0.004%.

[0060] Furthermore, the alloy may contain up to 0.50% vanadium.

[0061] • V <0.50% • V up to 0.40 or <0.50% • V: Maximum 0.20% or <0.20% • V: Maximum 0.08% or <0.10% • V: Maximum 0.05% or <0.05%.

[0062] Finally, regarding impurities, lead, zinc, and tin elements can also be expressed in the following proportions: Pb max. 0.002%, Zn max. 0.002%, Sn max. 0.002%.

[0063] Furthermore, the element beryllium can be represented as follows: Be less than 0.001%.

[0064] The powder according to the present invention is preferably produced in a vacuum inert gas atomization apparatus (VIGA). For this purpose, the alloy is first melted, optionally in open or vacuum, and optionally followed by ESU and / or VAR remelting. Subsequently, the powder is produced by atomizing the molten alloy in a vacuum inert gas atomization apparatus (VIGA). In this apparatus, the alloy is melted in vacuum induction melting (VIM), guided to an injection funnel, which is connected to a gas nozzle, where the molten metal is atomized into metal particles using an inert gas under high pressure of 5 to 100 bar. The molten metal is heated in a melting crucible 5 to 400°C above its melting point. The metal flow rate during atomization is 0.5 to 80 kg / min, and the gas flow rate is 2 to 150 m³. 3 The rate is per minute. Rapid cooling causes the metal particles to solidify into spherical shapes (spherical granules). The inert gas used during spraying may contain 0.01 to 100% nitrogen, as needed. The gas phase is then separated from the powder in a cyclone, and the powder is subsequently packaged.

[0065] In this case, the particles had a particle size of 5-250 μm, a pore area of ​​0.0-4% of the total area of ​​the evaluated object (pore > 1 μm), and a concentration of 2-approximately 8.5 g / cm³. 3 It has a bulk density up to the alloy density and is hermetically packaged in a protective gas atmosphere containing argon.

[0066] The particle size range of the powder is 5 to 250 μm, with a preferred range being 5 to 150 μm or 10 to 150 μm. This preferred range can be achieved by separating particles that are too fine and too large through a sieving or screening process. These processes are carried out under a protective gas and may be performed once or multiple times.

[0067] The aforementioned powder has gas inclusions with a pore area (pores > 1 μm) of 0.0 to 4% of the total area of ​​the evaluated object, in which case the preferred range is 0.0~2% 0.0~0.5% 0.0~0.2% 0.0~0.1% 0.0 to 0.05% is.

[0068] The powder has a bulk density of 2 g / cm 3 to about 8.5 g / cm, the density of the alloy, and the preferred range may be the following values: 3 Here, the preferred range may be the following values: 4 to 5 g / cm 3 2 to 8 g / cm 3 2 to 7 g / cm 3 3 to 6 g / cm 3 .

[0069] The amount of gas inclusion in the powder can reduce the porosity remaining in the manufactured part.

[0070] The inert gas during powder production may optionally be argon or a mixture of argon and less than 0.01 to 100% nitrogen. There may be the following restrictions on the nitrogen content: 0.01 to 80% 0.01 to 50% 0.01 to 30% 0.01 to 20% 0.01 to 10% 0.01 to 10% 0.1 to 5% 0.5 to 10% 1 to 5% 2 to 3%.

[0071] Alternatively, the inert gas may optionally be helium.

[0072] The inert gas should preferably have a purity of at least 99.996 volume %. In particular, it should have a nitrogen content of 0.0 to 10 ppmvm, an oxygen content of 0.0 to 4 ppmv, and an H2O content of ≦ 5 ppmv.

[0073] In particular, the inert gas preferably has a purity of at least 99.999% by volume. Specifically, it should have a nitrogen content of 0.0 to 5 ppmv, an oxygen content of 0.0 to 2 ppmv, and an H2O content of ≤ 3 ppmv.

[0074] The dew point in the apparatus is in the range of -10 to -120°C. Preferably, it is in the range of -30 to -100°C.

[0075] The pressure used when spraying the powder may preferably be 10 to 80 bar.

[0076] The powder produced from the alloy in this manner can be used for any manufacturing method that uses powder to produce a component or a layer on a component.

[0077] The powder produced in this manner can be used, in particular, for the additive manufacturing of components or layers on components.

[0078] Additive manufacturing can also be understood as generative manufacturing, rapid technology, rapid tooling, rapid prototyping, or similar concepts.

[0079] Generally, the following distinctions are made here: 3D printing using powder, Selective laser sintering, and Selective laser melting, Electron beam melting Binder jetting Laser overlay welding High-speed laser cladding welding Ultra-high-speed laser cladding welding Selective electron beam melting, etc.

[0080] The component or layer on the component manufactured using additive manufacturing is constructed from a layer thickness of 5 to 600 μm and has an organized structure immediately after manufacturing, with particles having an average particle size of 2 μm to 1000 μm that are stretched in the direction of the structure. The preferred range is 5 to 600 μm.

[0081] The powder produced from the aforementioned alloy can be used for the binder jet method. In this method, the component is constructed in layers. However, compared to the laser melting method, an organic binder is applied locally to ensure that the powder particles are bound together. After the binder hardens, the so-called green portion is debindered and sintered after the unbound powder is removed.

[0082] For powders produced from the aforementioned alloys, methods and additional equipment for preheating and postheating may be advantageous. An example is the EBM (electron beam melting) method, where a powder bed is selectively melted in layers by an electron beam. This process is carried out under high vacuum. Therefore, this process is particularly suitable for hard materials with low ductility and / or reactive materials. Preheating and postheating equipment can also be incorporated into laser-based methods.

[0083] Furthermore, the powder produced from the alloy can be used, as needed, for the manufacture of components using HIP (Hot Isostatic Pressing) or conventional sintering and extrusion methods. Additionally, combinations of additive manufacturing and subsequent HIP treatment are possible. If necessary, hot forming and / or cold forming, or alternating hot and cold forming, may also be performed. For hot forming, the component may be annealed at a temperature of 800-1290°C for 0.1-70 hours, then hot-formed, and optionally intermediate annealed at 800-1290°C for 0.05-70 hours. During and / or at the end of hot forming, the surface of the material may be cleaned by chemical and / or mechanical removal, as may be done several times. For cold forming, cold forming can be performed to a deformation degree of up to 98%, and in some cases intermediate annealing at 800-1250°C for 0.05 minutes to 70 hours, in some cases under a protective gas, such as argon or hydrogen, followed by cooling in air, in a moving annealing atmosphere, or in a water bath.

[0084] Components or layers on components manufactured from powder by various methods may be selectively subjected to solution heat treatment at a temperature range of 700–1250°C for 0.1 minutes–70 hours, optionally under a protective gas such as argon or hydrogen, followed by cooling in air, in a moving annealing atmosphere, or in a water bath. The surface may then be selectively cleaned or processed by pickling, blasting, grinding, turning, stripping, or milling. Such processing may be selectively performed partially or entirely before annealing.

[0085] The component manufactured from the aforementioned powder, or the layer on the component, has an average particle size of 2 μm to 2000 μm after annealing. A preferred range is 20 to 600 μm.

[0086] The components or layers on components manufactured from the powder according to the present invention should preferably be used under highly corrosive conditions, such as carburizing, sulfiding, or chlorinating environments, or carburizing and chlorinating environments, or carburizing, sulfiding, and chlorinating environments, particularly in areas where the atmosphere is dominant. These environments occur, for example, in waste incineration facilities, pyrolysis facilities, refining furnaces, in the chemical industry, in coal gasification facilities, and in the structures of industrial furnaces, in activated carbon filters, for the pyrolysis of waste, and in components for precious metal recovery. [Brief explanation of the drawing]

[0087] [Figure 1] This figure shows the depth of corrosion attack in various alloys after 2100 hours of aging in an H2S-containing gas in a Prenflo pilot facility, as a function of temperature. [Examples]

[0088] Tests conducted The evaluation of high-temperature corrosion resistance under highly corrosive conditions is performed (in Dechema) by the resistance of the material in a flowing synthesis gas atmosphere with elevated temperatures, in the example of carburizing, sulfiding, and chlorinating environments.

[0089] For this purpose, the dimensions are 20 x 8 x 4 mm 3 Samples were cut from semi-finished alloys, then 3 mm diameter holes were drilled, followed by wet polishing with SiC paper up to 1200 grit (particle size approximately 15 μm). The samples were degreased and washed with isopropanol in an ultrasonic bath. Each sample was suspended in a reaction vessel using the holes to form a ceramic crucible, and the detached corrosion products were collected. By weighing the crucible containing the corrosion products, the mass of the detached material could be determined. The sum of the mass of the detached material and the change in sample mass is the total change in sample mass. The specific mass change is the change in mass related to the surface of the sample. These are described below, and the specific net mass change is given by m Netto Regarding the change in specific total mass, m Brutto Regarding the change in specific mass of the exfoliated oxide, m spall It is called that.

[0090] A gas mixture consisting of 60% CO, 30% H2, 4% CO2, 1% H2S, 0.05% HCl, and 3.95% H2O flowed through the space of the reaction vessel. This mixture has carburizing (60% CO), sulfidation (1% H2S), and chlorination (0.05% HCl) properties. The tests were conducted at 500°C. The test duration was 1056 hours for each test, divided into 11 cycles of 96 hours each. In each test, there were two samples per alloy. The values ​​shown are the average values ​​of these two samples.

[0091] In the following study, after 1056 hours • Total mass increase ≤ 2.0 mg / cm³ 2 (4) Alloys exhibiting these characteristics are considered resistant to carburizing, sulfidation, and chlorination environments.

[0092] This is the relationship between nickel, silicon, and aluminum: Fc=-1.2+0.29×Ni-4.6×Si-4.4×Al≦2.5 (1a) This applies when the following conditions are met, and in the above formula, Ni, Si, and Al are the mass percent concentrations of the respective elements.

[0093] Weldability is evaluated by the scale of hot crack formation during welding. The greater the risk of hot crack formation, the worse the weldability of the material.

[0094] To quantify the susceptibility to hot cracking, various alloys were tested at the BAM (Federal Institute for Materials Research and Testing, Germany) using the MVT (Modified Balestrain / Transbalestrain) test. For this purpose, a sample with dimensions of 100 mm × 40 mm × 10 mm was prepared from the alloy. During the MVT test, a TIG seam (TIG: tungsten inert gas) was placed longitudinally on the upper side of the sample in a fully mechanized manner at a constant feed rate. A defined bending strain was applied to the sample as the arc passed through the center of the sample. At this time, the sample was bent along the welding direction (balestrain method). During this bending stage, hot cracks were formed in a locally limited test area on the MVT sample.

[0095] The tests were conducted under pure argon 4.8 at a bending strain of 4%, a drop (Gesenk) speed of 2 mm / sec, and an energy of 7.5 kJ / cm per unit length.

[0096] For evaluation, the lengths of all solidification cracks and reheat cracks visible on the sample at 25x magnification under an optical microscope are identified and summed. Using these results, the materials can be classified into three categories as shown in Table 2: "High Temperature Cracking Resistance" (Region 1), "Increased High Temperature Cracking Tendency" (Region 2), and "High Temperature Cracking Risk" (Region 3).

[0097] In the following study, alloys in Region 1 ("Resistance to Hot Cracking") and Region 2 ("Increased Tendency to Hot Cracking") during MVT testing were considered well weldable because conventionally weldable alloy AC66 is in Region 2. Alloys in Region 3 (risk of hot cracking) are generally difficult to weld. In particular, welding with a specific filler material (of equivalent composition to the material to be welded) is difficult or impossible.

[0098] The heat resistance was evaluated through a hot tensile test. This is determined at the desired temperature in a tensile test in accordance with DIN EN ISO 6892-2. At that time, the yield strength R p0.2 , tensile strength R m The fracture elongation A was identified. The test was performed on a round specimen with a diameter of 6 mm and an initial measurement length L030 mm in the measurement area. The yield strength R at 500°C was determined. p0.2 Or tensile strength R m This should at least reach the minimum value for alloy AC66 using conventional technology: • 500℃: R p0.2 ≥95MPa or R m ≥115 MPa (5a, 5b).

[0099] It is desirable that these values ​​are better than the minimum values ​​for alloy 45TM using conventional technology.

[0100] • 500℃: R p0.2 ≥150MPa or R m ≥500MPa (6a, 6b).

[0101] Particle size can be determined using the sectioning method.

[0102] manufacturing To verify the properties of components manufactured from powder, we use alloys molten in a vacuum furnace on a laboratory scale.

[0103] Tables 3a and 3b show analyses of batches melted at laboratory scale, along with several batches melted at industrial scale using prior art AC66(1.4877) and 45TM(2.4889), which are cited for comparison. Prior art batches are denoted by T, and those according to the present invention by E. Laboratory-scale melted batches are denoted by L, and industrial-scale melted batches by G.

[0104] The alloy blocks, vacuum-molten on a laboratory scale as shown in Tables 3a and 3b, were annealed at 900–1270°C for 8 hours, then hot-rolled to a final thickness of 13 or 6 mm using hot-rolling and a further intermediate annealing at 900–1270°C for 0.1–1 hour. The resulting sheets were solution-heat-treated at 800–1250°C for 1 hour. From these sheets, the necessary samples for measurement were prepared.

[0105] For alloys melted on an industrial scale, samples were obtained from industrial-scale production of factory-made sheets of appropriate thickness. From these sheets, the necessary samples for measurement were prepared.

[0106] The deformation forms of all alloys typically had particle sizes of 50–190 μm.

[0107] The following characteristics are compared for the example batches in Tables 3a and 3b: Examples of high corrosion resistance in highly corrosive environments include high-temperature corrosion resistance in carburized, sulfurized, and chlorinated environments. • Weldability as determined by MVT test • Creep resistance as determined by hot tensile testing.

[0108] A summary of the results is shown in Table 4.

[0109] Table 4 shows the results of corrosion tests in the form of total mass change and delamination after 1056 hours at 500°C in an atmosphere of 60% CO, 30% H2, 4% CO2, 1% H2S, 0.05% HCl, and 3.95% H2O. All alloys tested had a chromium content of approximately 27-28%. The conventional alloy AC66, with only 0.2% silicon, showed a significant difference of 10.92 mg / cm³. 2 This shows the maximum total mass change. Alloy 45™ using conventional technology with 2.6% silicon, and all tested laboratory-scale melted batches with silicon content exceeding 1.0%, showed 2.0 mg / cm³. 2 The following total mass changes are observed (2209, 250098, 250101, 250105, 250102, and 250107). Furthermore, if the aluminum content exceeds 0.40%, batches with a silicon content of 1.0% or less also satisfy equation (1a) Fc ≤ 2.5, resulting in 2.0 mg / cm³. 2 The following total mass changes are possible. This applies to batches 250084 (Si=0.59% and Al=0.95%), 250085 (Si=0.90% and Al=0.98%), 250106 (Si=0.98% and Al=0.80%), and 250108 (Si=0.70% and Al=0.86%).

[0110] Batches 250084, 250106, 250105, 250108, and 250107 are in accordance with the present invention, while batch 2209, which has a silicon content exceeding 1.50%, and batch 250098, which has a nickel content of 44.0%, are not.

[0111] Batch 250098 (Si=1.20% and Al=0.85%) shows a similar or higher total mass increase compared to batches 250106 (Si=0.98% and Al=0.80%) and 250101 (Si=1.01% and Al=0.75%), despite a significantly higher silicon content of 1.2%. Batch 250098 (Ni=44.0%) has a significantly higher nickel content compared to batches 250106 (Ni=35.6%) and 250101 (Ni=38.2%). This indicates that corrosion worsens with increasing nickel content. Therefore, the upper limit for nickel is set at a maximum of 40%.

[0112] 2.0 mg / cm³ 2 A total mass increase significantly exceeding (3.43 mg / cm³) 2 In the case of batch 250100 (Ni=38.2%, Si=0.99%, and Al=0.43%) which does not conform to the present invention, the aluminum content is somewhat too low, so formula (1a) is not satisfied, in contrast to batch 250101 (Ni=38.2%, Si=1.01%, and Al=0.75%). Similarly, 2.0 mg / cm³ 2 A total mass increase significantly exceeding (8.01 mg / cm³) 2 Alternatively, 5.35 mg / cm³ 2 In the case of batches 250103 (Ni=38.2%, Si=0.36%, and Al=0.82%) and 250099 (Ni=38.4%, Si=1.00%, and Al=0.20%) that do not conform to the present invention, the silicon and aluminum content is outside the scope of the claimed limitations, and furthermore, formula (1a) is not satisfied.

[0113] Alloys 250084 and 250106 according to the present invention still exhibit delamination. Furthermore, when formula (1c) Fc ≤ 1.0 is satisfied, this alloy no longer exhibits delamination (250107), and in the case of a moderate silicon content, surprisingly, it also exhibits delamination on the order of 45™ with 2.6% silicon and 0.16% aluminum at 1.0 mg / cm³. 2 It exhibits a very low total mass change, significantly below the threshold.

[0114] Table 4 shows the weldability ratings of alloys based on MTV testing. Alloy AC66, which is weldable using conventional techniques, is in region 2. Alloy 45TM is classified in region 3 (risk of hot cracking), and therefore has a strong tendency to form cracks, which makes welding difficult, and welding with specific filler materials difficult or impossible.

[0115] All batches not according to the present invention having a silicon content of 1.50% or more (45TM, batches 2091, 2099, 2100, 2200, 2203, 2207, 2208, 2209) are in region 3. Of the batches having a silicon content of approximately 1.4%, those with an aluminum content of less than 0.1% are in region 2 (batches 2093, 2101), while those with a higher aluminum content are already in region 3 (batches 2103, 2096, 2097, 2098). All batches with a silicon content of less than 1.3% are in region 1 or 2 (AC66, batches 2095, 2102, 250084~250108). All laboratory batches according to the present invention are located in either region 1 (batches 250084, 250106, 250105, 250108, and 250107) or region 2 (batch 250102).

[0116] The results of the hot tensile tests at 500°C in the table show the yield strength R for all alloys molten on a laboratory scale according to the present invention. p0.2 The tensile strength R of all alloys according to the present invention is 153 MPa or higher, and therefore significantly exceeds the minimum value of AC66 of 95 MPa. Though not significantly, they still exceed the minimum value of 45TM of 150 MPa (see Equations 5a and 6a). m The elongation was over 192 MPa, and therefore significantly higher than the minimum value of 115 MPa for AC66 (see Equation 5b). All hot tensile tests at 500°C showed an elongation of over 35%.

[0117] Therefore, the claimed limitation of alloy "E" according to the present invention as a powder can be specifically described as follows: A relatively low nickel content (with a high iron content (the remainder)) promotes less corrosion in highly corrosive environments, such as carburizing, sulfiding, and chlorinating atmospheres. Therefore, a nickel content of 40% is the upper limit. A nickel content that is too low (with a high iron content (the remainder)) promotes the formation of the sigma phase, especially with high chromium and silicon content. Therefore, a nickel content of 35% is the lower limit.

[0118] Chromium improves corrosion resistance in highly corrosive environments, such as carburizing, sulfiding, and chlorinating atmospheres. Too little chromium content means that when using the alloy in highly corrosive environments, the chromium concentration drops very rapidly below the acceptable limit, and a closed chromium oxide layer can no longer be formed. Therefore, when used in highly corrosive environments, such as carburizing, sulfiding, and chlorinating atmospheres, the lower limit for chromium is 26%. Too much chromium content, especially at high chromium content levels, promotes sigma phase formation in the alloy. Therefore, an upper limit of 30% chromium is considered.

[0119] Silicon improves corrosion resistance in highly corrosive environments, such as carburizing, sulfiding, and chlorinating atmospheres. Therefore, a minimum content of 0.40% is necessary. On the other hand, excessively high content, especially when the chromium content is high, impairs weldability and promotes the formation of the sigma phase. Therefore, the silicon content is limited to 1.50%.

[0120] A specific aluminum content improves corrosion resistance in highly corrosive environments, such as carburizing, sulfiding, and chlorinating atmospheres. Therefore, a minimum content of 0.40% is necessary. On the other hand, excessively high content, especially with high chromium and silicon content, impairs weldability. Therefore, the aluminum content is limited to 1.30%.

[0121] Manganese is useful for improving processability. However, its content is limited to 1.0% because this element reduces high-temperature corrosion resistance.

[0122] Even at very low magnesium and / or calcium content, processability is improved by binding sulfur, thereby avoiding the formation of low-molten NiS eutectic mixtures. Therefore, a minimum content of 0.0001% is required for magnesium and / or calcium. At excessively high content, Ni-Mg or Ni-Ca intermetallic phases may form, which significantly impairs processability. Therefore, the magnesium and / or calcium content is limited to a maximum of 0.05%.

[0123] For good creep resistance, a minimum carbon content of 0.015% is required. Carbon is limited to a maximum of 0.12% because beyond this level, the element reduces workability by excessively forming primary carbides.

[0124] A minimum nitrogen content of 0.001% is required, as this improves the processability and heat resistance of the material. Nitrogen is limited to a maximum of 0.150% because this element reduces processability by forming coarse carbonitrides.

[0125] The phosphorus content should be 0.030% or less because this surfactant impairs high-temperature corrosion resistance. Too low a phosphorus content results in higher costs. Therefore, the phosphorus content should be ≥0.001%.

[0126] To ensure the manufacturability of the alloy, the oxygen content must be 0.100% or less. Too low an oxygen content will increase costs. Therefore, the oxygen content must be ≥0.0001%.

[0127] The sulfur content should be kept as low as possible because this surfactant impairs high-temperature corrosion resistance. Therefore, it is set at a maximum of 0.010% sulfur.

[0128] Molybdenum is limited to less than 1.0% because this element reduces high-temperature corrosion resistance.

[0129] Tungsten is limited to less than 1.0% because this element also reduces high-temperature corrosion resistance.

[0130] Cobalt may be present in this alloy at a concentration of less than 1.0%. Higher concentrations reduce high-temperature corrosion resistance.

[0131] Copper is limited to less than 0.5% because this element reduces high-temperature corrosion resistance.

[0132] To exhibit sufficient resistance in highly corrosive environments, such as carburizing, sulfidation, and chlorination environments, the following relationship exists between nickel, silicon, and aluminum: Fc=-1.2+0.29×Ni-4.6×Si-4.4×Al≦2.5 (1a) The following conditions must be met, where Ni, Si, and Al are the mass percent concentrations of the respective elements. The restrictions on Fc are explained in detail in the preceding text.

[0133] If necessary, the high-temperature corrosion resistance can be further improved by adding oxygen-affinity elements. This is achieved by incorporating them into the oxide layer, where they block the diffusion pathway of oxygen at the grain boundaries.

[0134] To achieve enhanced high-temperature corrosion resistance, one or more elements—cerium, lanthanum, cerium mischmetal, yttrium, zirconium, and hafnium—are required, each at a minimum content of 0.001%. For cost reasons, the upper limit for each element is 0.20%. The following formula applies: FRE=0.714×Ce+0.720×La+1.124×Y+1.096×Zr+0.560×Hf≦0.10 (2a) The following conditions must be met, where Ce, La, Y, Zr, and Hf are the mass percent concentrations of the respective elements. This formula limits the total content of the elements cerium, lanthanum, yttrium, zirconium, and hafnium. Contents with FRE > 1.0 can also increase the corrosion rate and impair workability.

[0135] Titanium may be added as needed. Titanium increases high-temperature strength. High-temperature corrosion behavior may worsen beyond 0.50%, so 0.50% is the maximum value.

[0136] Niobium may be added as needed because it also increases high-temperature strength. Higher niobium content significantly increases costs. Therefore, the upper limit is set at 0.20%.

[0137] The alloy may also contain tantalum as needed, because tantalum also increases high-temperature strength. Higher tantalum content significantly increases costs. Therefore, the upper limit is set at 0.20%. A minimum content of 0.001% is required to achieve the desired effect.

[0138] Boron may be added to the alloy as needed, because it improves creep resistance. Therefore, a content of at least 0.0001% should be present. At the same time, this surfactant element worsens high-temperature corrosion resistance. Therefore, the maximum amount of boron is set at 0.008%.

[0139] Where necessary, vanadium is limited to a maximum of 0.50% because this element reduces high-temperature corrosion resistance.

[0140] Where necessary, lead is limited to a maximum of 0.002% because this element reduces high-temperature corrosion resistance. The same applies to zinc and tin.

[0141] Particle sizes smaller than 5 μm should be avoided as they worsen flow behavior, while particle sizes larger than 250 μm worsen behavior during additive manufacturing.

[0142] 2 g / cm³ 2 The excessively low bulk density worsens its behavior during additive manufacturing. (Approximately 8 g / cm³) 3 The maximum bulk density is given by the density of the alloy.

[0143] [Table 1]

[0144] [Table 2]

[0145] [Table 3a]

[0146] [Table 3b]

[0147] [Table 4]

[0148] Description of the drawing Figure 1: Corrosion attack depth of various alloys after 2100 hours of aging in a Prenflo pilot facility in H2S-containing gas, as a function of temperature.

Claims

1. The use of a nickel-iron-chromium alloy powder having excellent high-temperature corrosion resistance, wherein the powder consists of spherical particles with a size of 5 to 250 μm, and this alloy is (in mass%) 35.0-38% nickel, 26.0-30.0% chromium, Silicon content of over 0.7% to 1.50% 0.40-1.30% aluminum, 0.00-1.0% manganese, Each contains 0.0001 to 0.05% magnesium and / or calcium, 0.015-0.12% carbon, 0.001 to 0.150% nitrogen, 0.001-0.030% phosphorus, 0.0001 to 0.100% oxygen, Maximum 0.010% sulfur, Molybdenum less than 1.0%, Less than 1.0% cobalt, Less than 0.5% copper, Tungsten less than 1.0%, Titanium content 0.0-0.50%, Each has a niobium content and / or tantalum content of 0.0 to 0.50%, Boron content 0.0001-0.008%, Up to 0.50% vanadium, The remainder is iron, and impurities resulting from the normal process. It contains the following relationship: Fc=-1.2+0.29×Ni-4.6×Si-4.4×Al≦2.5 (1a) The following must be satisfied, where Ni, Si, and Al are the mass percent concentrations of the respective elements. Each contains 0.001 to 0.20% of one or more elements: cerium, lanthanum, yttrium, zirconium, and hafnium, where the following formula applies: FRE=0.714×Ce+0.720×La+1.124×Y+1.096×Zr+0.560×Hf≦0.10 (2a) The following must be satisfied, where Ce, La, Y, Zr, and Hf are the mass percent concentrations of the respective elements. When cerium and lanthanum are present together, cerium mischmetal (abbreviated as CeMM) is also used in a concentration of 0.001-0.20%, where FRE is as follows: FRE=0.716×CeMM+1.124×Y+1.096×Zr+0.560×Hf≦0.10 (3a) It must be changed as follows, where CeMM, Y, Zr, and Hf are the mass percent concentrations of the respective elements. The aforementioned use.

2. The use according to claim 1, having a nickel content of more than 35.0% to less than 38.0%.

3. The use according to claim 1 or 2, having a chromium content of more than 26.0% to 30.0%.

4. The use according to claim 1, having an aluminum content of 0.50% or more, or more than 0.50% but less than 1.30%.

5. The use according to claim 1, wherein the remaining iron content is 28.0% or more than 28.0% to 38.0%.

6. The use according to claim 1, wherein the impurity content is adjusted to a maximum of 0.002% lead, a maximum of 0.002% tin, and a maximum of 0.002% zinc.

7. The use according to claim 1, wherein the powder is produced using a vacuum inert gas atomizer (VIGA).

8. The use according to claim 1 for any manufacturing method using powder for manufacturing a component or a layer on a component.

9. The use according to claim 1 for additive manufacturing.

10. The use according to claim 1, as a component in the chemical industry, or in a component.

11. The use described in claim 1, as a component in a waste incineration facility or pyrolysis facility, or in a component.