Nippon Light Metal Company, Ltd.

Other

Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Novelis, Inc.

Sumitomo Light Metal Industries, Ltd.

Honda Giken Kkk

Kunihiro Yasunaga

Noboru Hayashi

Pizhi Zhao

Toshiya Anami

Hitoshi Kazama

David James Lloyd

Kevin Michael Gatenby

Hidetoshi Uchida

Paul A Wycliffe

Ichiro Okamoto

Simon Barker

Hideo Itoh

Takeshi Moriyama

Hideo Yoshida

Keiichi Sugiyama

Akira Goto

Edward S Luce

Kazumitsu Mizushima

Mitsuo Tsuge

Hiden Yoshida

Masayoshi Ohhashi

Tadashi Hakamada

Mark Gallerneault

An aluminum alloy sheet for motor vehicles is produced by casting a melt, containing 3.0-3.5 mass % Mg, 0.05-0.3 mass % Fe, 0.05-0.15 mass % Si, and less than 0.1 mass % Mn, a balance substantially being inevitable impurities and Al, into a slab having a thickness of 5 to 15 mm in a twin-belt caster so that cooling rate at &#xbc; depth of thickness of the slab is 20 to 200&#xb0; C./sec; winding the cast thin slab into a coiled thin slab subjected to cold rolling with a roll having a surface roughness of 0.2 to 0.7 &#x3bc;m Ra at a cold rolling reduction of 50 to 98%; subjecting the cold rolled sheet to final annealing either continuously in a CAL at a holding temperature of 400 to 520&#xb0; C. within 5 minutes or in a batch annealing furnace at a holding temperature of 300 to 400&#xb0; C. for 1 to 8 hours; and subjecting the resulting sheet to straightening with a leveler.

Process for producing an aluminum alloy sheet for motor vehicle

An aluminum alloy sheet is manufactured by preparing a slab having a thickness of 5 to 15 mm with a continuous casting machine by a continuous casting process using molten alloy containing 0.40% to 0.65% of Mg, 0.50% to 0.75% of Si, 0.05% to 0.20% of Cr, and 0.10% to 0.40% of Fe, a remainder being Al; winding the slab into a coil; cold-rolling the slab into a sheet; subjecting the sheet to solution heat treatment in such a manner that the sheet is heated to a temperature of 530&#xb0; C. to 560&#xb0; C. at a heating rate of 10&#xb0; C./sec or more and then maintained at the temperature for five seconds or more; quenching the sheet with water; coiling up the sheet; maintaining the sheet at a temperature of 60&#xb0; C. to 110&#xb0; C. for 3 to 12 hours; and then cooling the sheet to room temperature.

Aluminum alloy sheet and method for manufacturing the same

An aluminum alloy sheet having excellent press formability and stress corrosion cracking resistance, comprises 3.3 to 3.6 percent by weight of Mg and 0.1 to 0.2 percent by weight of Mn, furthermore, 0.05 to 0.3 percent by weight of Fe and 0.05 to 0.15 percent by weight of Si, and the remainder comprises Al and incidental impurities, wherein the sizes of intermetallic compounds is 5 &#x3bc;m or less, the recrystallized grain size is 15 &#x3bc;m or less in the region at a depth of 10 to 30 &#x3bc;m below the sheet surface, and the surface roughness is Ra 0.2 to 0.7 &#x3bc;m.

An aluminum alloy sheet for automotive use is provided which comprises a starting aluminum alloy sheet which has an alloy composition containing from 2 to 6% by weight of Mg, 0.15 to 1.0% by weight of Fe and from 0.03 to 2.0% by weight Mn, and a surface layer disposed over one surface of the starting alloy sheet to be pressed against electrodes for use in welding, the surface layer containing a particulate intermetallic compound has a particle diameter of 0.5 &mgr;m or more and a density of 4,000 pieces of particles per one mm or more. The product alloy sheet ensure least deformation of an electrode and stable weldability by means of continuous resistance spot welding.

Aluminum alloy sheet for spot welding

A continuously cast and rolled sheet of an aluminum alloy having Mg in a content of 3 to 6% by weight is annealed, followed by strain correction, heat and hold treatment at a given temperature between 240&deg; C. and 340&deg; C. for one hour or more, and slowly cooling treatment, to thereby provide an aluminum alloy sheet having enhanced resistance to stress corrosion cracking and improved shape fixability. The slowly cooling treatment is carried out at a cooling rate chosen from a preset cooling zone corresponding to a present temperature zone S defined in obliquely lined surround form in the accompanying drawing.

Process for producing an aluminum alloy sheet

The invention provides an aluminum alloy sheet that has excellent formability, high coat-baking hardenability, excellent corrosion resistance, and is particularly suitable for external automobile body plates. The aluminum alloy sheet comprises: 0.9 to 1.3 wt. % of Si, 0.4 to 0.6 wt. % of Mg, 0.05 to 0.15 wt. % of Mn, 0.01 to 0.1 wt. % of Ti, with the remainder comprising Al and inevitable impurities, while limiting Fe as an impurity to 0.2 wt. % or less and Cu as an impurity to 0.1 wt. % or less. The aluminum homogenizing an aluminum ingot with the above-described composition; cooling the homogenized ingot to a temperature of 450.degree. C. or below to begin hot-rolling; finishing hot-rolling in a temperature range from 250 to 350.degree. C.; applying intermediate annealing to the hot-rolled plate; conducting cold-rolling at a draft of 70% or more; applying a solid solution treatment followed by quenching the alloy sheet and holding it at 530.degree. C. or above for 60 sec. or less; forming a chromate film onto the quenched alloy sheet; forming a film of a lubricant containing a water-dispersible polyurethane resin and a natural wax onto the chromate film; then applying a heat treatment to the coated alloy sheet in a temperature range of from 200 to 240.degree. C. for 60 sec. or less.

Aluminum alloy sheet with excellent formability and method for

The invention provides an aluminum alloy sheet that has excellent formability, high coat-baking hardenability, and ensures a proof stress of 200 MPa or more after the coat-baking stage, and that gives favorable product surface quality after the forming stage and excellent corrosion resistance, and that is particularly suitable for external automobile body plates. The aluminum alloy sheet comprises: 0.9 to 1.3 wt. % of Si, 0.4 to 0.6 wt. % of Mg, 0.05 to 0.15 wt. % of Mn, 0.01 to 0.1 wt. % of Ti, with the remainder comprising Al and inevitable impurities, while limiting Fe as an impurity to 0.2 wt. % or less and Cu as an impurity to 0.1 wt. % or less; a coating film of a lubricant composition containing a water-dispersible polyurethane resin and a natural wax on the aluminum alloy sheet.

A method of bending extruded shapes of the present invention controls a bending radius and a bending angle in accordance with a moving distance of a movable bending die. In the bending process, hardness of an extruded shape to be processed is measured and converted into proof stress, and the bending condition for compensating the springback is determined. A correction coefficient C showing a ratio of a practical value of the moving distance and a theoretical value of the moving distance in a case of no spring-back occurring is defined by a function of Young's modulus E, geometrical coefficient Z, bending radius R and proof stress .sigma..sub.0.2 for the extruded shape to be processed. The correction coefficient C is obtained by measuring the hardness of the extruded shape to be processed, converting the measured hardness into the proof stress, and substituting the proof stress and a predetermined bending radius R into the function, and the practical value of the moving distance of the movable bending die is determined.

Method of bending extruded shapes

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Saitama, Japan

Kunihiro Yasunaga