# US 12,109,611 B2 · Part comprising an optimized steel material and its manufacturing process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,109,611 B2 - Document ID: US12109611B2 - Status: Granted - Kind: B2 - Application number: 17/091,584 - Filed: 2020-11-06 - Published: 2021-05-13 - Granted: 2024-10-08 - Earliest claimed: 2019-11-07 - Assignees: Commissariat A L'energie Atomique Et Aux Energies Alternatives - Applicants: Commissariat A L'energie Atomique Et Aux Energies Alternatives - Inventors: Olivier Hercher; Marine Chaussiniac; Jérôme Pradel; Aziz Chniouel; Hicham Maskrot; Fernando Lomello; Pierre-François Giroux; Pascal Aubry - Web page: https://patentgrep.com/patent/US12109611B2 ## CPC - B22F 10/00: Additive manufacturing of workpieces or articles from metallic powder (apparatus or devices therefor B22F12/00) - B22F 1/06: Metallic powder characterised by the shape of the particles (nanosized particles B22F1/054) - B22F 3/15: Hot isostatic pressing - B22F 5/00: Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product - B33Y 80/00: Products made by additive manufacturing - C22C 33/0285: {with Cr, Co, or Ni having a minimum content higher than 5%} - C22C 38/001: {containing N} - C22C 38/002: {containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60} - C22C 38/004: {Very low carbon steels, i.e. having a carbon content of less than 0,01%} - C22C 38/02: containing silicon - C22C 38/04: containing manganese - C22C 38/40: with nickel - C22C 38/44: with molybdenum or tungsten - C22C 38/46: with vanadium - C22C 38/58: with more than 1.5% by weight of manganese - B22F 2201/10: Inert gases - B22F 2301/35: Iron - B22F 2998/10: Processes characterised by the sequence of their steps - B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy - B33Y 10/00: Processes of additive manufacturing - B33Y 70/00: Materials specially adapted for additive manufacturing - C21D 2211/001: Austenite - C21D 2211/004: Dispersions; Precipitations - C22C 2200/04: Nanocrystalline - Y02P 10/25: Process efficiency - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING - C22C: ALLOYS (treatment of alloys C21D, C22F) - C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Part comprising a steel material whose constituent grains comprise a matrix in which precipitates are incorporated, the precipitates comprising at least one metallic element selected from a metallic element M, a metallic element M′, a metallic element M″ or mixtures thereof; the microstructure of the steel being such that the grains are equiaxed and the average grain size being such that the average of their largest dimension “D max” and/or the average of their smallest dimension “D min” is comprised between 10 μm and 50 μm. The steel material has optimised, stable and isotropic mechanical properties, in particular so that the steel material can best withstand mechanical and/or thermal stresses. ## Claims ### Claim 1 A part, comprising: a steel material comprising grains comprising a matrix into which precipitates are incorporated, wherein the steel material comprises, in weight percentage 16% to 20% chrome, 8% to 14% nickel, 0.001% to 0.030% carbon, 0.001% to 0.050% oxygen, 0% to 2% manganese, 0% to 3% molybdenum, 0% to 1% silicon, and iron; and wherein the precipitates comprise a metallic element comprising yttrium, titanium, iron, chromium, tungsten, silicon, zirconium, thorium, magnesium, manganese, aluminum, hafnium, and/or molybdenum, wherein the steel material has a microstructure of equiaxed grains having an average grain size average size in a range of from 10 μm to 50 μm in the largest dimension Dmax and/or a smallest dimension D, wherein the grains of the steel material are equiaxed in a plane which is parallel to superimposed layers resulting from an additive manufacturing process, wherein the grains of the steel material are equiaxed in a plane which is perpendicular to the superimposed layers resulting from the additive manufacturing process, wherein an average density with which the precipitates are distributed in the matrix of the steel material is in a range of from 2 to 100 precipitates/μm3, and wherein the part has a cellular structure or a honeycomb structure. ### Claim 2 (depends on 1) The part of claim 1, wherein the equiaxed grains of the steel material have an average Dmax/Dmin ratio, of the largest dimension Dmax to the smallest dimension Dmin, of a grain in a range of from 1 to 2. ### Claim 3 (depends on 2) The part of claim 2, wherein the precipitates of the steel material comprise titanium, iron, and/or chromium. ### Claim 4 (depends on 1) The part of claim 1, wherein the precipitates of the steel material comprise a metal oxide, a metal carbide, a metal oxycarbide, and/or an intermetallic compound. ### Claim 5 (depends on 1) The part of claim 1, wherein the precipitates of the steel material comprise a simple oxide MO2-x, wherein x is in a range of from 0 to 1, a mixed oxide MM′y′O5-x′, wherein x′ is greater than or equal to 0 but less than 5, and y′ is greater than 0 but less than or equal to 2, and/or a mixed oxide MM′y′M″y″O5-x″, wherein x″ is greater than or equal to 0 and less than 5, y′ is greater than 0 but less than or equal to 2, and y″ is in a range of from 0 to 2. ### Claim 6 (depends on 1) The part of claim 1, wherein the precipitates of the steel material comprise Y2O3, Fe2O3, FeO, Fe3O4, Cr2O3, TiO2, Al2O3, HfO2, SiO2, ZrO2, ThO2, MgO, MnO, and/or MnO2. ### Claim 7 (depends on 1) The part of claim 1, wherein the precipitates of the steel material comprise TiO2. ### Claim 8 (depends on 1) The part of claim 1, wherein the precipitates of the steel material comprise FeTiO3, Y2Ti2O7, and/or YTi2O5. ### Claim 9 (depends on 8) The part of claim 8, wherein the precipitates of the steel material further comprise a simple carbide MC8-x, wherein x is in a range of from 0 to 8, and/or a mixed carbide MM′y′C8-x′, wherein x′ is greater than or equal to 0 but less than 8 and y′ is in a range of from 0 to 5. ### Claim 10 (depends on 8) The part of claim 8, wherein the precipitates of the steel material further comprise TIC, SiC, AlC3, and/or CrC. ### Claim 11 (depends on 8) The part of claim 8, wherein the precipitates of the steel material further comprise (FeCr)7C3 and/or (FeCr)23C6. ### Claim 12 (depends on 1) The part of claim 1, wherein the precipitates of the steel material comprise a metal oxycarbide comprising a metal oxide and a metal carbide, wherein the metal oxide comprises a simple oxide MO2-x, wherein x is in a range of from 0 to 1, a mixed oxide MM′yO5-x′, wherein x′ is greater than or equal to 0 but less than 5, and y′ is greater than 0 but less than or equal to 2, and/or a mixed oxide MM′y′M″y″O5-x″, wherein x″ is greater than or equal to 0 and less than 5, y′ is greater than 0 but less than or equal to 2, and y″ is in a range of from 0 to 2, and wherein the metal carbide comprises a simple carbide MC8-x, wherein x is in a range of from 0 to 8, and/or a mixed carbide MM′y′C8-x′, wherein x′ is greater than or equal to 0 but less than 8 and y′ is in a range of from 0 to 5. ### Claim 13 (depends on 1) The part of claim 1, wherein the precipitates of the steel material comprise an YFe3, Fe2Ti, and/or FeCrWTi. ### Claim 14 (depends on 1) The part of claim 1, wherein the steel material comprises the precipitates in a range of from 0.1 to 1.5 wt. %. ### Claim 15 (depends on 4) The part of claim 4, wherein the precipitates of the steel material comprise the metal carbide, and wherein the precipitates have an average size in a range of from 10 nm to 50 nm. ### Claim 16 (depends on 4) The part of claim 4, wherein the precipitates of the steel material comprise the metal oxide and/or metal oxycarbide, and wherein the precipitates have an average size of from 10 nm to 100 nm. ### Claim 17 (depends on 1) The part of claim 1, wherein the average density with which the precipitates are distributed in the matrix of the steel material is in a range of from 2 to 6 precipitates/μm3. ### Claim 18 (depends on 1) The part of claim 1, wherein the steel material further comprises, in weight percentage: 0% to 0.11% nitrogen, 0% to 0.045% phosphorus, 0% to 0.05% sulfur, 0% to 0.0300% aluminum, 0% to 2% manganese, 0% to 3% molybdenum, and/or 0% to 0.003% vanadium. ### Claim 19 (depends on 1) The part of claim 1, wherein the matrix of the steel material comprises, in proportion by weight to a weight of the steel material, 0 ppm to 500 ppm of the yttrium, titanium, iron, chromium, tungsten, silicon, zirconium, thorium, magnesium, manganese, aluminium, hafnium, and/or molybdenum. ### Claim 20 (depends on 1) The part of claim 1, wherein the metallic element comprises the yttrium, titanium, tungsten, zirconium, thorium, aluminium, hafnium, silicon, manganese, or molybdenum. ### Claim 21 (depends on 1) The part of claim 1, wherein the steel material is of austenitic structure. ### Claim 22 (depends on 21) The part of claim 21, wherein the matrix of the steel material has a chemical composition of a 316 L or 304 L type steel. ### Claim 23 (depends on 1) A process for manufacturing the part according to claim 1, the process comprising: manufacturing the part by an additive manufacturing process. ### Claim 24 (depends on 23) The process of claim 23, wherein the additive manufacturing method is selective laser melting, selective electron beam melting, selective laser sintering, laser spraying, or binder spraying. ### Claim 25 (depends on 23) The process of claim 23, further comprising, after the manufacturing: hot isostatic pressing the part. ### Claim 26 (depends on 25) The process of claim 25, wherein the hot isostatic pressing comprises, successively, carried out in a chamber comprising an inert gaseous atmosphere at a pressure in a range of from 120 bar to 1800 bar: (A) heating the steel material at a constant temperature in a range of from 600 to 1400° C. at a rate of temperature increase in a range of from 500 to 1000° C./hour; (B) maintaining the constant temperature for a period in a range of from 15 minutes to 5 hours; and (C) lowering the constant temperature at a rate of temperature decrease in a range of from 500 to 1000° C./hour to reach room temperature. ### Claim 27 (depends on 26) The process of claim 26, wherein the inert gaseous atmosphere comprises argon and/or helium. ### Claim 28 (depends on 1) The part of claim 1, which consists of the steel material. ### Claim 29 A part, comprising: a steel material comprising grains comprising a matrix into which precipitates are incorporated, wherein the steel material comprises, in weight percentage 16% to 20% chrome, 8% to 14% nickel, 0.001% to 0.030% carbon, 0.001% to 0.050% oxygen, 0% to 2% manganese, 0% to 3% molybdenum, 0% to 1% silicon, and iron; and wherein the precipitates comprise a metallic element comprising yttrium, titanium, iron, chromium, tungsten, silicon, zirconium, thorium, magnesium, manganese, aluminum, hafnium, and/or molybdenum, wherein the steel material has a microstructure of equiaxed grains having an average grain size average size in a range of from 10 μm to 50 μm in the largest dimension Dmax and/or a smallest dimension D, wherein the grains of the steel material are equiaxed in a plane which is parallel to superimposed layers resulting from an additive manufacturing process, wherein the grains of the steel material are equiaxed in a plane which is perpendicular to the superimposed layers resulting from the additive manufacturing process, wherein an average density with which the precipitates are distributed in the matrix of the steel material is in a range of from 2 to 100 precipitates/μm3, and wherein the part has a lattice structure or a foam structure. ### Claim 30 (depends on 29) The part of claim 29, wherein the equiaxed grains of the steel material have an average Dmax/Dmin ratio, of the largest dimension Dmax to the smallest dimension Dmin, of a grain in a range of from 1 to 2.