Preservative steel plate having high resistance weldability, corrosion resistance and press formability for automobile fuel tanks
First Claim
1. A coated aluminized steel sheet suitable for fuel tanks, which consists of, in combination:
- (a) a steel sheet, (b) an aluminizing layer formed on one or both sides of said steel sheet and based on aluminum or an aluminum alloy containing 2-15 wt % silicon, and (c) a coating layer formed on at least one of said aluminizing layers, said coating layer being one or more films selected from the group consisting of;
i) an organic and inorganic composite chromate film having a film thickness of 0.1-2 μ
m and containing a resin and a chromic acid compound, with the re sin/metal chromium weight ratio in the range of 0.5-18, ii) an inorganic-based chromate film A with the coating layer formed to 10-200 mg/m2 in terms of metallic chromium, which comprises 100 parts by weight of chromic acid in terms of metallic chromium and 100-1000 parts by weight of colloidal silica, and further comprises at least one selected from the group consisting of 100-600 parts by weight of a phosphoric acid compound, 10-200 parts by weight of a phosphonic acid or phosphonic acid salt compound and less than 50 parts by weight of an organic resin, and iii) an inorganic-based chromate film B with a coating amount of at least 10 mg/m2 and less than 35 mg/m2 in terms of metallic chromium.
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Accused Products
Abstract
A coating aluminized steel sheet suitable for fuel tanks, which comprises (a) a steel sheet, (b) an aluminized-plating layer formed on one or both sides of the steel sheet and based on aluminum or an aluminum alloy containing 2-15 wt% silicon, and (c) a coating layer formed on at least one of the aluminizing layers and selected from the group consisting of i) a resin chromate film having a film thickness of 0.1-2 μm and containing a resin and a chromic acid compound, with the resin/metal chromium weight ratio in the range of 0.5-18, ii) an inorganic-based chromate film with the coating layer formed to 10-200 mg/m2 in terms of metallic chromium, which comprises 100 parts by weight of a chromic acid compound in terms of metallic chromium and 100-1000 parts by weight of colloidal silica, and further comprises any one or more of 100-600 parts by weight of a phosphoric acid compound, 10-200 parts by weight of a phosphonic acid or phosphonic acid salt compound and less than 50 parts by weight of a resin, and iii) an inorganic-based chromate film with a coating amount of at least 10 mg/m2 and less than 35 mg/m2 in terms of metallic chromium. There are provided automobile fuel tanks with excellent durability, forming formability and weldability, and a seam welding process for fuel tanks.
15 Citations
30 Claims
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1. A coated aluminized steel sheet suitable for fuel tanks, which consists of, in combination:
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(a) a steel sheet, (b) an aluminizing layer formed on one or both sides of said steel sheet and based on aluminum or an aluminum alloy containing 2-15 wt % silicon, and (c) a coating layer formed on at least one of said aluminizing layers, said coating layer being one or more films selected from the group consisting of;
i) an organic and inorganic composite chromate film having a film thickness of 0.1-2 μ
m and containing a resin and a chromic acid compound, with the re sin/metal chromium weight ratio in the range of 0.5-18,ii) an inorganic-based chromate film A with the coating layer formed to 10-200 mg/m2 in terms of metallic chromium, which comprises 100 parts by weight of chromic acid in terms of metallic chromium and 100-1000 parts by weight of colloidal silica, and further comprises at least one selected from the group consisting of 100-600 parts by weight of a phosphoric acid compound, 10-200 parts by weight of a phosphonic acid or phosphonic acid salt compound and less than 50 parts by weight of an organic resin, and iii) an inorganic-based chromate film B with a coating amount of at least 10 mg/m2 and less than 35 mg/m2 in terms of metallic chromium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 25, 29, 30)
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- 22. An automobile fuel tank wherein a pair of bowl-shaped bodies with flanges are integrated by continuous seam-welding of the flange substances, the automobile fuel tank being characterized in that the materials of which said bowl-shaped bodies are made are coating aluminized steel sheets which consist of aluminized steel sheets each having on one or both sides an aluminizing layer based on aluminum or an aluminum alloy containing 2-13 wt % silicon, and having a resin coating on the uppermost surface of the inner and/or outer side.
- 26. A seam welding process for fuel tanks, in which two coated aluminized steel sheets are combined which are aluminized steel sheets each having formed on one or both sides an aluminizing layer based on aluminum or an aluminum alloy containing 2-13 wt % silicon and having a resin coating formed on the one or both sides thereof, wherein said coated aluminized steel sheets have said aluminizing layer at least on the side corresponding to the inner side of the fuel tank, a resin film is provided on at least one of the steel sheet surfaces at the side where the steel sheets meet and/or on at least one of the steel sheet surfaces at the side where it contacts with an electrode wheel, and said two combined steel sheets are then seam welded between a pair of electrode wheels.
Specification