ALUMINUM ALLOY FORGING AND PRODUCTION METHOD THEREOF
Provided are an Al—Mg—Si based aluminum alloy forging excellent in mechanical properties in room temperature and hardly causing recrystallized grains and a production method thereof. An aluminum alloy forging consists of: Cu: 0.15 mass % to 1.0 mass %, Mg: 0.6 mass % to 1.15 mass %; Si: 0.95 mass % to 1.25 mass %; Mn: 0.4 mass % to 0.6 mass %; Fe: 0.2 mass % to 0.3 mass %; Cr: 0.11 mass % to 0.25 mass %; Ti: 0.012 mass % to 0.035 mass %; B: 0.0001 mass % to 0.03 mass %; Zn: 0.25 mass % or less; Zr: 0.05 mass % or less; and the balance being aluminum and inevitable impurities. The number of intermetallic compounds of Mg 2 Si with a minor axis of 0.5 μm or more present in a visual field area of 1.5815 mm 2 is 100 or less when a sectional structure of the aluminum alloy forging is observed at a magnification of 1,000 times.
1 . (canceled)
2 . A method of producing an aluminum alloy forging, the aluminum alloy forging consisting of:
Cu: 0.15 mass %, to 1.0 mass: Mg: 0.6 mass % to 1.15 mass %; Si: 0.95 mass % to 1.25 mass %; Mn: 0.4 mass % to 0.6 mass %: Fe: 0.2 mass % to 0.3 mass %: Cr: 0.11 mass % to 0.25 mass %; Ti: 0.012 mass to 0.035 mass %; B: 0.0001 mass % to 0.03 mass %; Zn 0.25 mass % or less; Zr: 0.05 mass % or less; and the balance being aluminum and inevitable impurities,
wherein the number of intermetallic compounds of Mg 2 Si with a minor axis of 0.5 μm or more present in a visual field area of 1.5815 mm 2 is 100 or less when a sectional structure of the aluminum alloy forging is observed at a magnification of 1,000 times
the method comprising:
a molten metal forming process of obtaining a molten metal;
a casting process of casting the molten metal obtained in the molten metal forming process to obtain a casting;
a homogenization heat treatment process of subjecting the casting obtained in the casting process to a homogenization heat treatment;
a forging process of forging the casting after the homogenization heat treatment process to obtain a forging;
a solution heat treatment process of subjecting the forging obtained in the forging process to a solution heat treatment;
a quenching process of quenching the forging after the solution heat treatment process; and
an aging process of aging the forging after the quenching process.
3 . The method of producing an aluminum alloy forging, as recited in claim 2 ,
wherein the homogenization heat treatment process is performed by holding the casting obtained in the casting process at a temperature of 370° C. to 560° C. for 4 hours to 10 hours;
wherein the forging process is performed by forging the casting after the homogenization heat treatment process at a heating temperature of 450° C. to 560° C.;
wherein the solution treatment process is performed by raising a temperature of the forging obtained in the forging process at a temperature raising rate of 5.0° C./min or more from 20° C. to 500° C. and holding the forging at 530° C. to 560° C. for 0.3 hours to 3 hours,
wherein the quenching process is performed by bringing an entire surface of the forging into contact with quenching water in a water tank within 5 seconds to 60 seconds after the solution treatment process for more than 5 minutes but not exceeding 40 minutes, and
wherein the aging process is performed by heating the forging after the quenching process at a temperature of 180° C. to 220° C. for 0.5 hours to 8 hours.
4 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein, in the aluminum alloy forging, the number of intermetallic compounds of Mg 2 Si with a minor axis of 0.5 μm or more present in a visual field area of 1.5815 mm 2 is 60 to 100 when a sectional structure of the aluminum alloy forging is observed at a magnification of 1,000 times.
5 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein, in the aluminum alloy forging, the number of intermetallic compounds of Mg 2 Si with a minor axis of 0.5 μm or more present in a visual field area of 1.5815 mm 2 is 60 to 78 when a sectional structure of the aluminum alloy forging is observed at a magnification of 1,000 times.
6 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein, in the aluminum alloy forging, the Zn content is 0%.
7 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein, in the aluminum alloy forging, the Zr content is 0%.
8 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein the aluminum alloy forging has a tensile strength at room temperature of 365 MPa or more.
9 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein the aluminum alloy forging has a tensile strength at room temperature of 385 MPa or more.
10 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein the aluminum alloy forging has a tensile strength at room temperature of 365 MPa to 401 MPa.
11 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein the aluminum alloy forging has a tensile strength at room temperature of 385 MPa to 401 MPa.
12 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein the solution treatment process is performed by raising a temperature of the forging obtained in the forging process at a temperature raising rate of 5.0° C./min to 240° C./min.
13 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein the solution treatment process is performed by raising a temperature of the forging obtained in the forging process at a temperature raising rate of 8.75° C./min to 240° C./min.
14 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein the solution treatment process is performed by raising a temperature of the forging obtained in the forging process at a temperature raising rate of 22.5° C./min to 240° C./min.
15 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein the solution treatment process is performed by raising a temperature of the forging obtained in the forging process at a temperature raising rate of 180° C./min to 240° C./min.
16 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein, in the aluminum alloy forging, the number of intermetallic compounds of Mg 2 Si with a minor axis of 0.5 μm or more present in a visual field area of 1.5815 mm 2 is 78 or less when a sectional structure of the aluminum alloy forging is observed at a magnification of 1,000 times.
17 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein, in the aluminum alloy forging, the number of intermetallic compounds of Mg 2 Si with a minor axis of 0.5 μm or more present in a visual field area of 1.5815 mm 2 is 65 or less when a sectional structure of the aluminum alloy forging is observed at a magnification of 1,000 times.
18 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein, in the aluminum alloy forging, the number of intermetallic compounds of Mg 2 Si with a minor axis of 0.5 μm or more present in a visual field area of 1.5815 mm 2 is 65 to 78 or less when a sectional structure of the aluminum alloy forging is observed at a magnification of 1,000 times.
19 . The method of producing an aluminum alloy forging as recited in claim 2 , wherein, in the aluminum alloy forging, the number of intermetallic compounds of Mg 2 Si with a minor axis of 0.5 μm or more present in a visual field area of 1.5815 mm 2 is 60 to 65 or less when a sectional structure of the aluminum alloy forging is observed at a magnification of 1,000 times.