Abstract: A fuel tank (10) includes: a lower panel (12) made of steel and an upper panel (11) made of steel; and at least one pillar (100) made of steel which is disposed in an interior space (V) formed by the lower panel (12) and the upper panel (11) facing each other and of which a first end portion is fixed to the lower panel (12) and a second end portion is fixed to the upper panel (11) in a state where the second end portion is disposed in a hole formed in the upper panel (11).

Abstract: A fuel tank (10) includes: a lower panel (12) made of steel and an upper panel (11) made of steel; and at least one pillar (100) made of steel which is disposed in an interior space (V) formed by the lower panel (12) and the upper panel (11) facing each other and of which a first end portion is fixed to the lower panel (12) and a second end portion is fixed to the upper panel (11) in a state where the second end portion is disposed in a hole formed in the upper panel (11).

Abstract: A hot-dip Sn—Zn-based alloy-plated steel sheet according to an aspect of the present invention includes: a steel sheet having a predetermined chemical composition; a diffusion alloy layer provided on one surface or both surfaces of the steel sheet; and a Sn—Zn-plated layer provided on the diffusion alloy layer, in which the diffusion alloy layer contains Fe, Sn, Zn, Cr, and Ni, an area ratio of a Sn—Fe—Cr—Zn phase to a Sn—Fe—Ni—Zn phase in the diffusion alloy layer is 0.01 or more and less than 2.5, the diffusion alloy layer has a coverage of 98% or more with respect to the one surface, the Sn—Zn-plated layer contains 1% to 20% of Zn by mass % and a remainder consisting of Sn and impurities, and an adhesion amount of the Sn—Zn-plated layer is 10 to 80 g/m2 per one surface.

Abstract: A hot-dip Sn—Zn-based alloy-plated steel sheet according to an aspect of the present invention includes: a steel sheet having a predetermined chemical composition; a diffusion alloy layer provided on one surface or both surfaces of the steel sheet; and a Sn—Zn-plated layer provided on the diffusion alloy layer, in which the diffusion alloy layer contains Fe, Sn, Zn, Cr, and Ni, an area ratio of a Sn—Fe—Cr—Zn phase to a Sn—Fe—Ni—Zn phase in the diffusion alloy layer is 0.01 or more and less than 2.5, the diffusion alloy layer has a coverage of 98% or more with respect to the one surface, the Sn—Zn-plated layer contains 1% to 20% of Zn by mass % and a remainder consisting of Sn and impurities, and an adhesion amount of the Sn—Zn-plated layer is 10 to 80 g/m2 per one surface.

Abstract: A tailored blank for hot stamping includes a welded portion formed by butt-welding a first aluminum-plated steel sheet and a second aluminum-plated steel sheet, an Average Al concentration of a weld metal in the welded portion is in a range of 0.3 mass % to 1.5 mass %, an Ac3 point of the weld metal is 1250° C. or lower, and furthermore, an aluminum layer formed during the butt-welding is present on a surface of the welded portion.

Abstract: A fillet arc welded joint formed by fillet arc welding at least two metal members, comprising a remelted and solidified portion obtained by irradiating a laser at a weld toe portion of the fillet arc welding of at least one metal member and a region including a boundary of the heat affected zone caused by the fillet arc welding at the surface of that metal member, the remelted and solidified portion being a range from a surface of the metal member to a depth of ½ or less of the thickness of that metal member, an average effective crystal grain diameter of prior austenite at a heat affected zone from a boundary of the remelted and solidified portion at the surface of the metal member to a depth of 0.1 mm in the thickness direction of the metal member being 20 ?m or less.

Abstract: A laser welded joint excellent in joint strength preventing a bead from cracking and comprised of exactly the number of weld beads required for joint strength in overlay laser welding of steel sheets forming multiple ring-shaped weld beads, produced by a step of overlaying a plurality of metal sheets and forming a first weld bead and a step of firing a laser beam to successively form a further two or more weld beads at the outside of the first weld bead by laser irradiation, the surface hardness of the weld bead increasing from the inside bead to the outside bead.

Abstract: A laser welded joint has weld metal provided between a plurality of steel sheets. A chemical composition of the weld metal has predetermined components, and average hardness of the weld metal is 350 to 540 in Vickers hardness. In the weld metal, distribution density of porosities having a diameter of 2 ?m to 50 ?m is equal to or less than 5.0 pieces/mm2. In the weld metal, distribution density of oxide inclusions having a diameter of 3 ?m or more is 0.1 to 8.0 pieces/mm2.

Abstract: A fillet arc welded joint formed by fillet arc welding at least two metal members, comprising a remelted and solidified portion obtained by irradiating a laser at a weld toe portion of the fillet arc welding of at least one metal member and a region including a boundary of the heat affected zone caused by the fillet arc welding at the surface of that metal member, the remelted and solidified portion being a range from a surface of the metal member to a depth of ½ or less of the thickness of that metal member, an average effective crystal grain diameter of prior austenite at a heat affected zone from a boundary of the remelted and solidified portion at the surface of the metal member to a depth of 0.1 mm in the thickness direction of the metal member being 20 ?m or less.

Abstract: A tailored blank for hot stamping includes a welded portion formed by butt-welding a first aluminum-plated steel sheet and a second aluminum-plated steel sheet, an Average Al concentration of a weld metal in the welded portion is in a range of 0.3 mass % to 1.5 mass %, an Ac3 point of the weld metal is 1250° C. or lower, and furthermore, an aluminum layer formed during the butt-welding is present on a surface of the welded portion.

Abstract: A tailored blank for hot stamping includes a welded portion formed by butt-welding a first aluminum-plated steel sheet and a second aluminum-plated steel sheet, an Average Al concentration of a weld metal in the welded portion is in a range of 0.3 mass % to 1.5 mass %, an Ac3 point of the weld metal is 1250° C. or lower, and furthermore, an aluminum layer formed during the butt-welding is present on a surface of the welded portion.

Abstract: A laser welded joint has weld metal provided between a plurality of steel sheets. A chemical composition of the weld metal has predetermined components, and average hardness of the weld metal is 350 to 540 in Vickers hardness. In the weld metal, distribution density of porosities having a diameter of 2 ?m to 50 ?m is equal to or less than 5.0 pieces/mm2. In the weld metal, distribution density of oxide inclusions having a diameter of 3 ?m or more is 0.1 to 8.0 pieces/mm2.

Abstract: The present invention has as its object to provide a laser welded joint excellent in joint strength preventing a bead from cracking and comprised of exactly the number of weld beads required for joint strength and a laser welding method for the same in overlay laser welding of steel sheets forming multiple ring-shaped weld beads. The present invention is a laser welded joint excellent in joint strength preventing a bead from cracking and comprised of exactly the number of weld beads required for joint strength in overlay laser welding of steel sheets forming multiple ring-shaped weld beads, produced by a step of overlaying a plurality of metal sheets and forming a first weld bead and a step of firing a laser beam to successively form a further two or more weld beads at the outside of the first weld bead by laser irradiation, the surface hardness of the weld bead increasing from the inside bead to the outside bead.

Abstract: At a plurality of welding positions in an overlap portion of a plurality of members including a high-tensile steel sheet whose carbon content is 0.07 weight % or more, first beads (31 to 36) in a closed loop shape or a closed loop-like shape and second beads (41 to 46) in a closed loop shape or a closed loop-like shape on inner sides of the first bead (31 to 36) are formed by remote laser welding for joining. At this time, there are a procedure for successively forming the plural first beads (31 to 36) and a procedure for successively forming the plural second beads (41 to 46) for the plural formed first beads (31 to 36), and in both of the cases, the beads are each formed at a position except the closest welding position among the plural welding positions. Consequently, it is possible to enhance strength of a weld zone and to suppress welding deformation.

Abstract: A solid wire for gas shielded arc welding comprising the following in terms of mass-% with respect to a total mass of the wire including plating: C: from 0.03 to 0.15%, Si: from 0.2 to 0.5%, Mn: from 0.3 to 0.8%, P: 0.02% or less, S: 0.02% or less, Al: from 0.1 to 0.3%, Ti: from 0.001 to 0.2%, Cu: from 0 to 0.5%, Cr: from 0 to 2.5%, Nb: from 0 to 1.0%, and V: from 0 to 1.0%, wherein the balance is Fe and impurities, and the following value of X is in a range of from 1.5 to 3.5 mass %. A welding metal, wherein the X value of the following formula is in a range of from 1.0 to 4.0%. Further, a welded joint, a weldment, and a welding method of the welded joint, utilizing the solid wire or the weld metal.

Abstract: A tailored blank for hot stamping includes a welded portion formed by butt-welding a first aluminum-plated steel sheet and a second aluminum-plated steel sheet, an Average Al concentration of a weld metal in the welded portion is in a range of 0.3 mass % to 1.5 mass %, an Ac3 point of the weld metal is 1250° C. or lower, and furthermore, an aluminum layer formed during the butt-welding is present on a surface of the welded portion.

Abstract: At a plurality of welding positions in an overlap portion of a plurality of members including a high-tensile steel sheet whose carbon content is 0.07 weight % or more, first beads (31 to 36) in a closed loop shape or a closed loop-like shape and second beads (41 to 46) in a closed loop shape or a closed loop-like shape on inner sides of the first bead (31 to 36) are formed by remote laser welding for joining. At this time, there are a procedure for successively forming the plural first beads (31 to 36) and a procedure for successively forming the plural second beads (41 to 46) for the plural formed first beads (31 to 36), and in both of the cases, the beads are each formed at a position except the closest welding position among the plural welding positions. Consequently, it is possible to enhance strength of a weld zone and to suppress welding deformation.