Clad plate and process for production thereof

A tubular member for heat exchangers produced by forming a clad member comprising a core material, an outer skin layer provided on one surface of the core material, and an inner skin layer provide on the other surface thereof via an intermediate layer into a tubular configuration with the outer skin layer facing outward,

• wherein the core material is made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Mg:
• 0.2 to 1.5 mass %, and the balance being Al and impurities,
• wherein the outer skin layer is made of an aluminum alloy comprising Zn:
• 0.01 to 4 mass %, and the balance being Al and impurities,
• wherein the intermediate layer is made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Zn:
• 0.35 to 3 mass %, and the balance being Al and impurities, and
• wherein the inner skin layer is made of an Al—Si series brazing material.

A flat tube for heat exchangers produced by forming a clad member comprising a core material, an outer skin layer provided on one surface of the core material, and an inner skin layer provide on the other surface thereof via an intermediate layer into a tubular configuration with the outer skin layer facing outward,

• wherein the core material is made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Mg:
• 0.2 to 1.5 mass %, and the balance being Al and impurities,
• wherein the outer skin layer is made of an aluminum alloy comprising Zn:
• 0.01 to 4 mass %, and the balance being Al and impurities,
• wherein the intermediate layer is made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Zn:
• 0.35 to 3 mass %, and the balance being Al and impurities, and
• wherein the inner skin layer is made of an Al—Si series brazing material.

A header for heat exchangers produced by forming a clad member comprising a core material, an outer skin layer provided on one surface of the core material, and an inner skin layer provide on the other surface thereof via an intermediate layer into a tubular configuration with the outer skin layer facing outward,

• wherein the core material is made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Mg:
• 0.2 to 1.5 mass %, and the balance being Al and impurities,
• wherein the outer skin layer is made of an aluminum alloy comprising Zn:
• 0.01 to 4 mass %, and the balance being Al and impurities,
• wherein the intermediate layer is made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Zn:
• 0.35 to 3 mass %, and the balance being Al and impurities, and
• wherein the inner skin layer is made of an Al—Si series brazing material.

A method of manufacturing a clad member, the steps comprising:

• disposing an outer skin layer made of an aluminum alloy comprising Zn:
• 0.01 to 4 mass %, and the balance being Al and impurities on one surface of a core material made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Mg:
• 0.2 to 1.5 mass %, and the balance being Al and impurities;
• disposing an inner skin layer made of an Al—Si series brazing material on the other surface of the core material via an intermediate layer made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Zn:
• 0.35 to 3 mass %, and the balance being Al and impurities;
• subjecting the core material, the inner skin layer, the outer skin layer and the intermediate layer to hot clad-rolling to obtain an intermediate material;
• and
• subjecting the intermediate material to intermediate annealing at any point between rolling passes after the clad-rolling but before cold rolling, or between cold rolling after the clad-rolling.

A heat exchanger in which a plurality of flat tubes and fins disposed between the flat tubes are brazed and the plurality of flat tubes and a header connected to one ends of the flat tubes are brazed,

• wherein at least one of the flat tube and the header is a heat exchanger tubular member produced by forming a clad member having an outer skin layer provided on one surface side of a core material and an inner skin layer provided on the other side thereof via an intermediate layer into a tubular configuration with the outer skin layer facing outward, and
• wherein the core material of the clad member is made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Mg:
• 0.2 to 1.5 mass %, and the balance being Al and impurities, the outer skin layer is made of an aluminum alloy comprising Zn:
• 0.01 to 4 mass %, and the balance being Al and impurities, the intermediate layer is made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Zn:
• 0.35 to 3 mass %, and the balance being Al and impurities, and the inner skin layer is made of an Al—Si series brazing material.

A method of manufacturing a heat exchanger comprising a plurality of flat tubes, fins disposed between the flat tubes, and a header connected to one ends of the flat tubes, the method comprising the steps of:

• preparing a heat exchanger tubular member produced by forming a clad member having a core material, an outer skin layer provided on one surface side of a core material, and an inner skin layer provided on the other side thereof via an intermediate layer into a tubular configuration with the outer skin layer facing outward as at least one of the flat tube and the header, wherein the core material of the clad member is made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Mg:
• 0.2 to 1.5 mass %, and the balance being Al and impurities, the outer skin layer is made of an aluminum alloy comprising Zn:
• 0.01 to 4 mass %, and the balance being Al and impurities, the intermediate layer is made of an aluminum alloy comprising Mn:
• 0.8 to 2 mass %, Zn:
• 0.35 to 3 mass %, and the balance being Al and impurities, and the inner skin layer is made of an Al—Si series brazing material;
• and
• brazing the flat tubes and the fins, and the flat tubes and the header using fluoride series flux.