High strength alloy steels and methods of making the same

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.

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.

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.

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%.

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%.

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%.