# US 2021/0340645 A1 · Cobalt based alloy product, method for manufacturing same, and cobalt based alloy article > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0340645 A1 - Document ID: US20210340645A1 - Status: Published application - Kind: A1 - Application number: 16/620,719 - Filed: 2019-03-07 - Published: 2021-11-04 - Earliest claimed: 2019-03-07 - Assignees: Mitsubishi Power, Ltd. - Applicants: Mitsubishi Power, Ltd. - Inventors: Yuting WANG; Shinya IMANO; Shigenobu EGUCHI - Web page: https://patentgrep.com/patent/US20210340645A1 ## CPC - B22F 1/06: Metallic powder characterised by the shape of the particles (nanosized particles B22F1/054) - B22F 5/009: {of turbine components other than turbine blades (of turbine blades B22F5/04)} - B22F 10/20: Direct sintering or melting - B22F 10/28: Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] - B22F 10/36: of energy beam parameters - B22F 10/64: by thermal means (control of energy beam parameters for post heating B22F10/364) - B33Y 40/20: Post-treatment, e.g. curing, coating or polishing - B33Y 70/00: Materials specially adapted for additive manufacturing - B33Y 80/00: Products made by additive manufacturing - C22C 19/07: based on cobalt - C22F 1/10: of nickel or cobalt or alloys based thereon - F01D 5/00: Blades; Blade-carrying members (nozzle boxes F01D9/02); Heating, heat-insulating, cooling or antivibration means on the blades or the members {(special arrangements in rotors dealing with breaking off of part thereof F01D21/045)} - F01D 5/28: Selecting particular materials; {Particular measures relating thereto;} Measures against erosion or corrosion - F01D 25/005: {Selecting particular materials} - F01D 25/007: {Preventing corrosion} - B22F 5/04: of turbine blades - B22F 2003/248: {Thermal after-treatment} - B33Y 10/00: Processes of additive manufacturing - F01D 5/286: {Particular treatment of blades, e.g. to increase durability or resistance against corrosion or erosion (F01D5/288 takes precedence)} - F05D 2260/95: Preventing corrosion - F05D 2300/17: Alloys - F28F 21/081: {Heat exchange elements made from metals or metal alloys} - F28F 21/086: {from titanium or titanium alloys} - F28F 21/087: {from nickel or nickel alloys} - 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) - C22F: CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS (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) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract There is provided a cobalt-based alloy product comprising: in mass %, 0.08-0.25% C; 0.1% or less B; 10-30% Cr; 5% or less Fe and 30% or less Ni, the total amount of Fe and Ni being 30% or less; W and/or Mo, the total amount of W and Mo being 5-12%; at least one of Ti, Zr, Hf, V, Nb and Ta, the total amount of Ti, Zr, Hf, V, Nb and Ta being 0.5-2%; 0.5% or less Si; 0.5% or less Mn; 0.003-0.04% N; and the balance being Co and impurities. The cobalt-based alloy product is a polycrystalline body of matrix phase crystal grains, wherein MC type carbide phase grains are dispersively precipitated in the matrix phase crystal grains at an average intergrain distance of 0.13 to 2 μm and M23C6 type carbide phase grains are precipitated on grain boundaries of the matrix phase crystal grains. ## Claims ### Claim 1 A product formed of a cobalt based alloy, the cobalt based alloy having a chemical composition comprising: 0.08 to 0.25 mass % of carbon; 0.1 mass % or less of boron; 10 to 30 mass % of chromium; 5 mass % or less of iron, 30 mass % or less of nickel, the total amount of the iron and the nickel being 30 mass % or less; tungsten and/or molybdenum, the total amount of the tungsten and the molybdenum being 5 to 12 mass %; at least one of titanium, zirconium, hafnium, vanadium, niobium and tantalum, the total amount of the titanium, the zirconium, the hafnium, the vanadium, the niobium and the tantalum being 0.5 to 2 mass %; 0.5 mass % or less of silicon; 0.5 mass % or less of manganese; 0.003 to 0.04 mass % of nitrogen; and the balance being cobalt and impurities, the impurities including 0.5 mass % or less of aluminum, and 0.04 mass % or less of oxygen, wherein the product is a polycrystalline body of matrix phase crystal grains, and wherein in the polycrystalline body MC type carbide phase grains and M23C6 type carbide phase grains are co-precipitated, the MC type carbide phase grains being dispersively precipitated in the matrix phase crystal grains at an average intergrain distance of 0.13 to 2 μm, the M23C6 type carbide phase grains being precipitated on grain boundaries of the matrix phase crystal grains. ### Claim 2 (depends on 1) The product according to claim 1, wherein: the MC type carbide phase grains are grains of an MC type carbide phase comprising the titanium, the zirconium, the hafnium, the vanadium, the niobium and/or the tantalum; and the M23C6 type carbide phase grains are grains of an M23C6 type carbide phase comprising the chromium, the iron, the tungsten, the molybdenum and/or the manganese. ### Claim 3 (depends on 1) The product according to claim 1, wherein: in the case that the chemical composition includes the titanium, content of the titanium is 0.01 to 1 mass %; in the case that the chemical composition includes the zirconium, content of the zirconium is 0.05 to 1.5 mass %; in the case that the chemical composition includes the hafnium, content of the hafnium is 0.01 to 0.5 mass %; in the case that the chemical composition includes the vanadium, content of the vanadium is 0.01 to 0.5 mass %; in the case that the chemical composition includes the niobium, content of the niobium is 0.02 to 1 mass %; and in the case that the chemical composition includes the tantalum, content of the tantalum is 0.05 to 1.5 mass %. ### Claim 4 (depends on 1) The product according to claim 1, wherein the product exhibits a creep rupture time of 1,200 hours or more by a creep test under conditions of a temperature of 850° C. and a stress of 168 MPa. ### Claim 5 (depends on 1) The product according to claim 1, wherein the product is a high temperature member. ### Claim 6 (depends on 5) The product according to claim 5, wherein the high temperature member is a turbine stator blade, a turbine rotor blade, a turbine combustor nozzle, or a heat exchanger. ### Claim 7 (depends on 1) A method for manufacturing the cobalt based alloy product according to claim 1, the method comprising: an alloy powder preparation step of preparing a cobalt based alloy powder having the chemical composition, the cobalt based alloy powder having a particle size; a selective laser melting step of forming an additively manufactured article, the step comprising alternate repetition of an alloy powder bed preparation substep of laying the cobalt based alloy powder such that it forms an alloy powder bed having a predetermined thickness and a laser melting solidification substep of irradiating a predetermined region of the alloy powder bed with a laser beam to locally melt and rapidly solidify the cobalt based alloy powder in the region, the laser beam having an output power and a scanning speed; a first heat treatment step of subjecting the additively manufactured article to a first heat treatment at a temperature ranging of 750° C. or more and less than 1,100° C.; and a second heat treatment step of subjecting the first heat-treated article to a second heat treatment at a temperature ranging from 600° C. to 1,000° C. but less than the temperature of the first heat treatment, wherein in the a selective laser melting step, the predetermined thickness of the alloy powder bed h (unit: μm), the output power of the laser beam P (unit: W), and the scanning speed of the laser beam S (unit: mm/s) are controlled to satisfy the following formulas: “15