# US 2019/0376168 A1 · High strength alloy steels and methods of making the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0376168 A1 - Document ID: US20190376168A1 - Status: Published application - Kind: A1 - Application number: 16/005,716 - Filed: 2018-06-12 - Published: 2019-12-12 - Earliest claimed: 2018-06-12 - Inventors: Mohsen Askari Paykani; Hamid Reza Shahverdi - Web page: https://patentgrep.com/patent/US20190376168A1 ## CPC - C22C 38/58: with more than 1.5% by weight of manganese - C21D 8/0226: {Hot rolling} - C22C 38/02: containing silicon - C22C 38/06: containing aluminium - C22C 38/34: with more than 1.5% by weight of silicon - C22C 38/38: with more than 1.5% by weight of manganese - C22C 38/42: with copper - C21D 2211/001: Austenite - 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) ## Abstract A method for producing alloy steel is provided. An alloy mixture may be melted to produce a melted alloy mixture. The alloy mixture comprises 2 to 4 weight % chromium (Cr), 12 to 16 weight % manganese (Mn), at most 4 weight % silicone (Si), 1 to 3 weight % aluminum (Al), at most 0.3 weight % carbon (C) and iron (Fe). The melted alloy mixture may be formed into a product. The product may be heated to produce a thermally homogenized product. The thermally homogenized product may be hot rolled into a plate with a first thickness. The plate may be warm rolled at a warm rolling temperature until the plate has a second thickness. The warm rolling temperature may be configured such that a crystal structure of the plate has 30 to 70 volume % austenite. The warm rolling temperature may be between 350° C. and 550° C. ## Claims ### Claim 1 An alloy steel, comprising: 2 to 4 weight % chromium (Cr); 12 to 16 weight % manganese (Mn); at most 4 weight % silicone (Si); 1 to 3 weight % aluminum (Al); at most 0.3 weight % carbon (C); and iron (Fe). ### Claim 2 (depends on 1) The alloy steel of claim 1, having a nickel (Ni) content of at most 1.5 weight %. ### Claim 3 (depends on 1) The alloy steel of claim 1, having a copper (Cu) content of at most 3 weight %. ### Claim 4 (depends on 1) The alloy steel of claim 1, wherein: the chromium is present at 2.9 to 3.1 weight %; the manganese is present at 13.9 to 14.1 weight %; the silicone is present at 0.9 to 1.1 weight %; the aluminum is present at 1.9 to 2.1 weight %; and the carbon is present at 0.09 to 0.11 weight %. ### Claim 5 (depends on 4) The alloy steel of claim 4, having at least one of: a tensile strength of at least 1765 megapascals (MPa), a yield strength of at least 1476 MPa and a total elongation of at least 13%; a tensile strength of at least 1508 MPa, a yield strength of at least 978 and a total elongation of at least 27.8%; a tensile strength of at least 1696 MPa, a yield strength of at least 907 and a total elongation of at least 27.8%; a tensile strength of at least 1538 MPa, a yield strength of at least 1029 and a total elongation of at least 25%; or a tensile strength of at least 1481 MPa, a yield strength of at least 335 and a total elongation of at least 24.8%. ### Claim 6 (depends on 4) The alloy steel of claim 4, having a copper content of 1.5 to 2.5 weight %. ### Claim 7 (depends on 6) The alloy steel of claim 6, having at least one of: a tensile strength of at least 1515 MPa, a yield strength of at least 1099 MPa and a total elongation of at least 41%; a tensile strength of at least 1368 MPa, a yield strength of at least 1029 MPa and a total elongation of at least 44.8%; a tensile strength of at least 1353 MPa, a yield strength of at least 986 MPa and a total elongation of at least 39.3%; a tensile strength of at least 1414 MPa, a yield strength of at least 753 MPa and a total elongation of at least 42%; or a tensile strength of at least 1268 MPa, a yield strength of at least 392 MPa and a total elongation of at least 42%. ### Claim 8 (depends on 1) The alloy steel of claim 1, having a nickel content of 1.0 to 1.6 weight % and a copper content of 0.5 to 1.1 weight %, wherein: the chromium is present at 2.4 to 2.6 weight %; the manganese is present at 13.9 to 14.1 weight %; the silicone is present at 2.6 to 2.8 weight %; the aluminum is present at 1.9 to 2.1 weight %; and the carbon is present at 0.19 to 0.21 weight %. ### Claim 9 (depends on 8) The alloy steel of claim 8, having at least one of: a tensile strength of at least 1628 MPa, a yield strength of at least 1485 MPa and a total elongation of at least 25.8%; a tensile strength of at least 1698 MPa, a yield strength of at least 1584 MPa and a total elongation of at least 37%; a tensile strength of at least 1700 MPa, a yield strength of at least 1499 MPa and a total elongation of at least 39.4%; a tensile strength of at least 1657 MPa, a yield strength of at least 1482 MPa and a total elongation of at least 41%; or a tensile strength of at least 1649 MPa, a yield strength of at least 547.2 MPa and a total elongation of at least 40.1%. ### Claim 10 A method for producing an alloy steel, comprising: melting an alloy mixture to produce a melted alloy mixture; forming the melted alloy mixture into a product; heating the product to produce a thermally homogenized product; hot rolling the thermally homogenized product into a plate with a first thickness; and warm rolling the plate at a warm rolling temperature until the plate has a second thickness, wherein the warm rolling temperature is configured such that a crystal structure of the plate has 30 to 70 volume % austenite. ### Claim 11 (depends on 10) The method of claim 10, wherein at least one of: the warm rolling temperature is between 350° C. and 550° C.; the second thickness is between 0.9 millimeters (mm) and 1.1 mm; or a thickness reduction of the first thickness to the second thickness is 60% to 70%. ### Claim 12 (depends on 10) The method of claim 10, wherein at least one of: the thermally homogenized product is hot rolled at one or more hot rolling temperatures between 800° C. and 1200° C.; the first thickness is between 2 mm and 4 mm; or a thickness reduction of a thickness of the thermally homogenized product to the first thickness is 70% to 90%. ### Claim 13 (depends on 10) The method of claim 10, wherein the product comprises at least one of one or more slabs, one or more ingots or one or more billets. ### Claim 14 (depends on 10) The method of claim 10, wherein the product is heated at 1000° C. to 1200° C. for 3 to 5 hours to produce the thermally homogenized product. ### Claim 15 (depends on 10) The method of claim 10, comprising: prior to warm rolling the plate and responsive to hot rolling the plate, cooling the plate until the plate reaches a second temperature between 500° C. and 900° C.; and responsive to the plate reaching the second temperature, maintaining a temperature of the plate for 45 min to 75 min at a third temperature between 500° C. and 900° C. ### Claim 16 The method of 10, comprising: responsive to warm rolling the plate, heat treating the plate at a heat treatment temperature, wherein the heat treatment temperature is configured such that at least one of: 15 to 25 volume % austenite is formed; 40 to 60 volume % austenite is formed; 70 to 90 volume % austenite is formed; or at least 95 volume % austenite is formed. ### Claim 17 A method for producing an alloy steel, comprising: melting an alloy mixture to produce a melted alloy mixture, wherein the alloy mixture comprises: 2 to 4 weight % chromium (Cr); 12 to 16 weight % manganese (Mn); at most 4 weight % silicone (Si); 1 to 3 weight % aluminum (Al); at most 0.3 weight % carbon (C); and iron (Fe); forming the melted alloy mixture into a product; heating the product to produce a thermally homogenized product; hot rolling the thermally homogenized product into a plate with a first thickness; and warm rolling the plate at a warm rolling temperature until the plate has a second thickness, wherein the warm rolling temperature is configured such that a crystal structure of the plate has 30 to 70 volume % austenite. ### Claim 18 The method of 17, comprising: responsive to warm rolling the plate, heat treating the plate at a heat treatment temperature for a specified duration of time, wherein: the chromium is present at 2.9 to 3.1 weight %; the manganese is present at 13.9 to 14.1 weight %; the silicone is present at 0.9 to 1.1 weight %; the aluminum is present at 1.9 to 2.1 weight %; and the carbon is present at 0.09 to 0.11 weight %; and at least one of: the heat treatment temperature is between 180° C. and 220° C. and the specified duration of time is between 15 minutes and 25 minutes, wherein the plate has a tensile strength of at least 1508 MPa, a yield strength of at least 978 and a total elongation of at least 27.8%; the heat treatment temperature is between 430° C. and 470° C. and the specified duration of time is between 15 minutes and 25 minutes, wherein the plate has a tensile strength of at least 1696 MPa, a yield strength of at least 907 and a total elongation of at least 27.8%; the heat treatment temperature is between 500° C. and 540° C. and the specified duration of time is between 15 minutes and 25 minutes, wherein the plate has a tensile strength of at least 1538 MPa, a yield strength of at least 1029 and a total elongation of at least 25%; or the heat treatment temperature is between 800° C. and 900° C. and the specified duration of time is between 5 minutes and 15 minutes, wherein the plate has a tensile strength of at least 1481 MPa, a yield strength of at least 335 and a total elongation of at least 24.8%. ### Claim 19 The method of 17, comprising: responsive to warm rolling the plate, heat treating the plate at a heat treatment temperature for a specified duration of time, wherein: the alloy mixture has a copper content of 1.5 to 2.5 weight %; the chromium is present at 2.9 to 3.1 weight %; the manganese is present at 13.9 to 14.1 weight %; the silicone is present at 0.9 to 1.1 weight %; the aluminum is present at 1.9 to 2.1 weight %; and the carbon is present at 0.09 to 0.11 weight %; and at least one of: the heat treatment temperature is between 270° C. and 310° C. and the specified duration of time is between 15 minutes and 25 minutes, wherein the plate has a tensile strength of at least 1368 MPa, a yield strength of at least 1029 MPa and a total elongation of at least 44.8%; the heat treatment temperature is between 430° C. and 470° C. and the specified duration of time is between 15 minutes and 25 minutes, wherein the plate has a tensile strength of at least 1353 MPa, a yield strength of at least 986 MPa and a total elongation of at least 39.3%; the heat treatment temperature is between 560° C. and 600° C. and the specified duration of time is between 15 minutes and 25 minutes, wherein the plate has a tensile strength of at least 1414 MPa, a yield strength of at least 753 MPa and a total elongation of at least 42%; or the heat treatment temperature is between 800° C. and 900° C. and the specified duration of time is between 5 minutes and 15 minutes, wherein the plate has a tensile strength of at least 1268 MPa, a yield strength of at least 392 MPa and a total elongation of at least 42%. ### Claim 20 The method of 17, comprising: responsive to warm rolling the plate, heat treating the plate at a heat treatment temperature for a specified duration of time, wherein: the alloy mixture has a copper content of 0.5 to 1.1 weight %; the alloy mixture has a nickel content of 1.0 to 1.6 weight %; the chromium is present at 2.4 to 2.6 weight %; the manganese is present at 13.9 to 14.1 weight %; the silicone is present at 2.6 to 2.8 weight %; the aluminum is present at 1.9 to 2.1 weight %; and the carbon is present at 0.19 to 0.21 weight %; and at least one of: the heat treatment temperature is between 280° C. and 320° C. and the specified duration of time is between 15 minutes and 25 minutes, wherein the plate has a tensile strength of at least 1698 MPa, a yield strength of at least 1584 MPa and a total elongation of at least 37%; the heat treatment temperature is between 450° C. and 490° C. and the specified duration of time is between 15 minutes and 25 minutes, wherein the plate has a tensile strength of at least 1700 MPa, a yield strength of at least 1499 MPa and a total elongation of at least 39.4%; the heat treatment temperature is between 530° C. and 570° C. and the specified duration of time is between 15 minutes and 25 minutes, wherein the plate has a tensile strength of at least 1657 MPa, a yield strength of at least 1482 MPa and a total elongation of at least 41%; or the heat treatment temperature is between 800° C. and 900° C. and the specified duration of time is between 5 minutes and 15 minutes, wherein the plate has a tensile strength of at least 1649 MPa, a yield strength of at least 547.2 MPa and a total elongation of at least 40.1%.