Nippon Light Metal Company, Ltd.

Tomohiro Sasaki

Hideki Suzuki

Yoshito Oki

Masae Nagasawa

Haruo Sugiyama

Toshiya Anami

Nobuki Takahashi

An aluminum alloy fin material for a heat exchanger having suitable strength before brazing enabling easy fin formation, having high strength after brazing, having a high thermal conductivity (electrical conductivity) after brazing, and having superior sag resistance, erosion resistance, self corrosion prevention, and sacrificial anode effect, a method of production of the same, and a method of production of a heat exchanger using the fin material are provided, that is, an aluminum alloy fin material having a chemical composition of Si: 0.7 to 1.4 wt %, Fe: 0.5 to 1.4 wt %, Mn: 0.7 to 1.4 wt %, and Zn: 0.5 to 2.5 wt %, Mg as an impurity limited to 0.05 wt % or less, and the balance of unavoidable impurities and Al, and having a tensile strength after brazing of 130 MPa or more, a yield strength after brazing of 45 MPa or more, a recrystallized grain size after brazing of 500 &#x3bc;m or more, and an electrical conductivity after brazing of 47% IACS or more, a method of producing an aluminum alloy fin material comprising cold rolling/annealing/cold rolling/annealing/cold rolling a thin slab continuously cast by a twin-belt system from a melt of the above composition under predetermined conditions, and a method of production of a heat exchanger comprising cooling the fin material at a predetermined rate after brazing heating.

Aluminum alloy fin material for heat exchanger and method of production of same and method of production of heat exchanger by brazing fin material

A heat exchanger use high strength aluminum alloy fin material having a high strength and excellent in thermal conductivity, erosion resistance, sag resistance, sacrificial anodization effect, and self corrosion resistance, characterized by containing Si: 0.8 to 1.4 wt %, Fe: 0.15 to 0.7 wt %, Mn: 1.5 to 3.0 wt %, and Zn: 0.5 to 2.5 wt %, limiting the Mg as an impurity to 0.05 wt % or less, and having a balance of ordinary impurities and Al in chemical composition, having a metal structure before brazing of a fibrous crystal grain structure, a tensile strength before brazing of not more than 240 MPa, a tensile strength after brazing of not less than 150 MPa, and a recrystallized grain size after brazing of 500 &#x3bc;m or more.

High strength aluminum alloy fin material and method of production of same

A heat exchanger use high strength aluminum alloy fin material having a high strength and excellent in thermal conductivity, elusion resistance, sag resistance, sacrificial anodization effect, and self corrosion resistance, characterized by containing Si: 0.8 to 1.4 wt %, Fe: 0.15 to 0.7 wt %, Mn: 1.5 to 3.0 wt %, and Zn: 0.5 to 2.5 wt %, limiting the Mg as an impurity to 0.05 wt % or less, and having a balance of ordinary impurities and Al in chemical composition, having a metal structure before brazing of a fibrous crystal grain structure, a tensile strength before brazing of not more than 240 MPa, a tensile strength after brazing of not less than 150 MPa, and a recrystallized grain size after brazing of 500 &#x3bc;m or more.

[PROBLEMS] To provide an aluminum alloy fin material for a heat exchanger, which has high strength and high heat conductivity after brazing, and is excellent in the resistance to sagging, erosion and self-corrosion and the in the sacrificial anode effect. [MEANS FOR SOLVING PROBLEMS] A method for producing an aluminum alloy fin material for a heat exchanger which comprises providing a molten aluminum alloy having a chemical composition, in wt %, that Si: 0.5 to 1.5%, Fe: 0.15 to 1.00%, Mn: 0.8 to 3.0%, Zn: 0.5 to 2.5%, with the proviso that the content of Mg as an impurity is limited to 0.05 wt % or less, and the balance: Al and inevitable impurities, casting the molten alloy continuously into a thin slab having a thickness of 5 to 10 mm by the use of a twin belt casting machine, winding up the slab into a roll, cold-rolling the slab into a sheet having a thickness of 0.05 to 2.0 mm, subjecting the sheet to an inter annealing at 350 to 500&#xb0; C., and cold-rolling the annealed sheet with a cold reduction rate of 10 to 96%, to prepare a sheet having a final thickness of 40 to 200 &#x3bc;m, and optionally subjecting the final sheet to a final annealing (a softening process) at a holding temperature of 300 to 400&#xb0; C.

High strength aluminum alloy fin material for heat exchanger and method for production thereof

[PROBLEMS] To provide an aluminum alloy fin material for a heat exchanger, which has high strength and high heat conductivity after brazing, and is excellent in the resistance to sagging, erosion and self-corrosion and the in the sacrificial anode effect. [MEANS FOR SOLVING PROBLEMS] A method for producing an aluminum alloy fin material for a heat exchanger which comprises providing a molten aluminum alloy having a chemical composition, in wt %, that Si: 0.5 to 1.5%, Fe: 0.15 to 1.0%, Mn: 0.8 to 3.0%, Zn: 0.5 to 2.5%, with the proviso that the content of Mg as an impurity is limited to 0.05 wt % or less, and the balance: Al and inevitable impurities, casting the molten alloy continuously into a thin slab having a thickness of 5 to 10 mm by the use of a twin belt casting machine, winding up the slab into a roll, cold-rolling the slab into a sheet having a thickness of 0.05 to 2.0 mm, subjecting the sheet to an inter annealing at 350 to 500&#xb0; C., and cold-rolling the annealed sheet with a cold reduction rate of 10 to 96%, to prepare a sheet having a final thickness of 40 to 200 &#x3bc;m, and optionally subjecting the final sheet to a final annealing (a softening process) at a holding temperature of 300 to 400&#xb0; C.

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Shizuoka, Japan

Tomohiro Sasaki