Abstract: There are provided a flux cored wire for joining dissimilar materials with each other, capable of enhancing a bonding strength upon joining an aluminum-base material with a steel-base material, and excellent in bonding efficiency, a method for joining the dissimilar materials with each other, and a bonded joint obtained by the method. In particular, there is provided a method for joining dissimilar materials with each other, in the case of melt weld-bonding of high-strength dissimilar materials with each other, that is, the high-strength steel member with the high-strength 6000 series aluminum alloy member and in the case of the steel member being a galvanized steel member. In one mode, use is made of a flux cored wire wherein the interior of an aluminum alloy envelope is filled up with a flux, the flux has fluoride composition containing a given amount of AlF3 without containing chloride, and the aluminum alloy of the envelope contains Si in a range of 1 to 13 mass %.

Abstract: This aims to provide a pulse laser welding aluminum alloy material, which can prevent the occurrence of an abnormal portion, when an A1000-series aluminum material is welded with a pulse laser, so that a satisfactory welded portion can be homogeneously formed, and a battery case. The pulse laser welding aluminum alloy material is made of an A1000-series aluminum material, and has a viscosity of 0.0016 Pa·s or less in a liquid phase. Alternatively, the pulse laser welding aluminum alloy material has such a porosity generation rate of 1.5 (?m2/mm) or less in the pulse-laser welded portion as is numerically defined by dividing the porosity total area (?m2), as indicated by the product of the sectional area and the number of porosities, by the length (mm) of an observation section.

Abstract: There are provided a flux cored wire for joining dissimilar materials with each other, capable of enhancing a bonding strength upon joining an aluminum-base material with a steel-base material, and excellent in bonding efficiency, a method for joining the dissimilar materials with each other, and a bonded joint obtained by the method. In particular, there is provided a method for joining dissimilar materials with each other, in the case of melt weld-bonding of high-strength dissimilar materials with each other, that is, the high-strength steel member with the high-strength 6000 series aluminum alloy member and in the case of the steel member being a galvanized steel member. In one mode, use is made of a flux cored wire wherein the interior of an aluminum alloy envelope is filled up with a flux, the flux has fluoride composition containing a given amount of AlF3 without containing chloride, and the aluminum alloy of the envelope contains Si in a range of 1 to 13 mass %.

Abstract: A flux-cored wire for laser welding or MIG welding different materials, wherein the different materials are aluminum or an aluminum alloy material and a galvanized steel material. The flux-cored wire contains a cylindrical aluminum alloy sheath containing: aluminum, 0.8-1.9 mass % Si, at most 0.1 mass % Mn, 0.1 mass % Mg, and 0.1 mass % Fe; and a flux filled in a space within the sheath and containing 20-60 mass % cesium fluoride, wherein the percentage filling of the flux is 5-20 mass % with respect to the total mass of the flux-core wire.

Abstract: There are provided a flux-cored wire for welding different materials, a method for laser welding of different materials and a method for MIG welding of different materials which can improve tensile shear strength of a welded joint portion and peeling strength of a welded portion interface in welding aluminum or an aluminum alloy material and a steel material. The flux-cored wire has a cylindrical sheath comprising an aluminum alloy which contains Si in an amount of 1.5 to 2.5% by mass and Zr in an amount of 0.05 to 0.25% by mass, with the remainder being aluminum and inevitable impurities, and a flux filling inside this sheath and containing cesium fluoride in an amount of 20 to 60% by mass, and the packing fraction of the flux being 5 to 20% by mass of the total mass of the wire.

Abstract: The joining method includes a step of lapping the aluminum alloy plate and the plated steel plate via adhesive, a pre-heating step of clamping both metal plates lapped in the lapping step between a pair of electrodes for spot welding and applying pressure thereto, and applying a current between the pair of electrodes, a cooling step of pressurizing both metal plates at a pressing force higher than that at the start of the pre-heating step in a state where conduction between the electrodes is stopped, and continuing this pressurization over a predetermined cooling time, and a welding step of pressurizing both metal plates at a pressing force higher than that at the start of the pre-heating step, and welding both of the metal plates by applying a current higher than the conduction current value in the pre-heating step between the pair of electrodes.

Abstract: A flux-cored wire for laser welding or MIG welding different materials, wherein the different materials are aluminum or an aluminum alloy material and a galvanized steel material. The flux-cored wire contains a cylindrical aluminum alloy sheath containing: aluminum, 0.8-1.9 mass % Si, at most 0.1 mass % Mn, 0.1 mass % Mg, and 0.1 mass % Fe; and a flux filled in a space within the sheath and containing 20-60 mass % cesium fluoride, wherein the percentage filling of the flux is 5-20 mass % with respect to the total mass of the flux-core wire.

Abstract: There are provided a flux-cored wire for welding different materials, a method for laser welding of different materials and a method for MIG welding of different materials which can improve tensile shear strength of a welded joint portion and peeling strength of a welded portion interface in welding aluminum or an aluminum alloy material and a steel material. The flux-cored wire has a cylindrical sheath comprising an aluminum alloy which contains Si in an amount of 1.5 to 2.5% by mass and Zr in an amount of 0.05 to 0.25% by mass, with the remainder being aluminum and inevitable impurities, and a flux filling inside this sheath and containing cesium fluoride in an amount of 20 to 60% by mass, and the packing fraction of the flux being 5 to 20% by mass of the total mass of the wire.

Abstract: The joining method of the present invention includes a lapping step of lapping the aluminum alloy plate (1) and the plated steel plate (2) via the adhesive (5), a pre-heating step of clamping both of the metal plates (1, 2) that have been lapped in the lapping step between a pair of electrodes (7, 7) for spot welding and applying pressure thereto, and applying a current between the pair of electrodes (7, 7), a cooling step of pressurizing, after the pre-heating step, both of the metal plates (1, 2) at a pressing force which is higher than that at the start of the pre-heating step in a state where conduction between the electrodes (7, 7) is stopped, and continuing this pressurization over a predetermined cooling time, and a welding step of pressurizing, after the cooling step, both of the metal plates (1, 2) at a pressing force which is higher than that at the start of the pre-heating step, and welding both of the metal plates (1, 2) by applying a current which is higher than the conduction current value in th

Abstract: A steel/aluminum welded structure comprises a hot-dip Al-coated steel sheet 1 spot welded with an aluminum or aluminum alloy sheet 2. The steel sheet 1 is coated with a coating layer 4 containing, by mass, 3-12% of Si and 0.5-5% of Fe. An area ratio of an Al—Fe binary alloy layer, formed at the joint boundary, is controlled to 90% or less. An unalloyed region 9 exists between an Al—Fe—Si ternary alloy layer 6 at an interface of a steel substrate 5 with the coating layer 4 interface and the Al—Fe binary alloy layer at the joint boundary. A steel substrate 5 preferably contains 0.002-0.020% of N for formation of a N-enriched surface layer in contact with the coating layer 4. The N-enriched layer impedes propagation of the brittle Al—Fe binary alloy layer to the whole of the joint boundary and raises joint strength of the steel/aluminum welded structure.

Abstract: This aims to provide a pulse laser welding aluminum alloy material, which can prevent the occurrence of an abnormal portion, when an A1000-series aluminum material is welded with a pulse laser, so that a satisfactory welded portion can be homogeneously formed, and a battery case. The pulse laser welding aluminum alloy material is made of an A1000-series aluminum material, and has a viscosity of 0.0016 Pa·s or less in a liquid phase. Alternatively, the pulse laser welding aluminum alloy material has such a porosity generation rate of 1.5 (?m2/mm) or less in the pulse-laser welded portion as is numerically defined by dividing the porosity total area (?m2), as indicated by the product of the sectional area and the number of porosities, by the length (mm) of an observation section.

Abstract: There are provided a flux cored wire for joining dissimilar materials with each other, capable of enhancing a bonding strength upon joining an aluminum-base material with a steel-base material, and excellent in bonding efficiency, a method for joining the dissimilar materials with each other, and a bonded joint obtained by the method. In particular, there is provided a method for joining dissimilar materials with each other, in the case of melt weld-bonding of high-strength dissimilar materials with each other, that is, the high-strength steel member with the high-strength 6000 series aluminum alloy member and in the case of the steel member being a galvanized steel member. In one mode, use is made of a flux cored wire wherein the interior of an aluminum alloy envelope is filled up with a flux, the flux has fluoride composition containing a given amount of AlF3 without containing chloride, and the aluminum alloy of the envelope contains Si in a range of 1 to 13 mass %.

Abstract: A joined part of an aluminum-coated steel sheet and an aluminum sheet is composed of an intermetallic compound layer which exists in a region in which a part of a coated layer exists before the joining and an aluminum melted and solidified part which also exists on the side of the aluminum sheet to enclose the intermetallic compound layer. The atoms existing on the surface of the aluminum melted and solidified part are intermetallic-bonded with atoms which exist on the surface of the steel sheet except in the region in which the intermetallic compound layer exists seen in the plan view. Further, the area of the intermetallic compound layer is limited to 60% or less of the total area of the joined part at the interface between the aluminum-coated steel sheet and the aluminum sheet. Thus, the area of the aluminum melted and solidified part exceeds 40% of the total area of the joined part. The strong joining having a high fracture energy can be provided at a high efficiency.

Abstract: A steel/aluminum welded structure comprises a hot-dip Al-coated steel sheet 1 spot welded with an aluminum or aluminum alloy sheet 2. The steel sheet 1 is coated with a coating layer 4 containing, by mass, 3-12% of Si and 0.5-5% of Fe. An area ratio of an Al—Fe binary alloy layer, formed at the joint boundary, is controlled to 90% or less. An unalloyed region 9 exists between an Al—Fe—Si ternary alloy layer 6 at an interface of a steel substrate 5 with the coating layer 4 interface and the Al—Fe binary alloy layer at the joint boundary. A steel substrate 5 preferably contains 0.002-0.020% of N for formation of a N-enriched surface layer in contact with the coating layer 4. The N-enriched layer impedes propagation of the brittle Al—Fe binary alloy layer to the whole of the joint boundary and raises joint strength of the steel/aluminum welded structure.

Abstract: A joined part of an aluminum-coated steel sheet and an aluminum sheet is composed of an intermetallic compound layer which exists in a region in which a part of a coated layer exists before the joining and an aluminum melted and solidified part which also exists on the side of the aluminum sheet to enclose the intermetallic compound layer. The atoms existing on the surface of the aluminum melted and solidified part are intermetallic-bonded with atoms which exist on the surface of the steel sheet except in the region in which the intermetallic compound layer exists seen in the plan view. Further, the area of the intermetallic compound layer is limited to 60% or less of the total area of the joined part at the interface between the aluminum-coated steel sheet and the aluminum sheet. Thus, the area of the aluminum melted and solidified part exceeds 40% of the total area of the joined part. The strong joining having a high fracture energy can be provided at a high efficiency.

Abstract: An aluminum alloy sheet according to the present invention essentially consists of an aluminum alloy containing 0.5 to 1.4% magnesium, 0.6 to 1.5% silicon, and 0.005 to 0.1% titanium, all by weight, and aluminum and inevitable impurities for the remainder, and is adjusted so that the ratio of the silicon content to the magnesium content is 0.65 or more. The average crystal grain size and the electric conductivity of the aluminum alloy sheet are 70 .mu.m or less and 43 to 51% IACS, respectively.The composition of the aluminum alloy is adjusted in this manner, and the crystal grain size and the electric conductivity are restricted within the specific ranges by controlling the manufacturing conditions. Thus, there may be provided an aluminum alloy sheet which is improved in arc-weldability and resistance to filiform corrosion, as well as in formability and bake-hardenability at low temperature.