A laser welding method includes a laser beam irradiation step of oscillating a laser beam and condensing the laser beam on a welding portion, and a scanning step of scanning a spot of the laser beam. In the execution of laser welding, while oscillating the laser beam, a screw portion having a dot shape in a plan view is formed in which a metal member is melted by scanning of the spot so as to circle around a predetermined position, and while the metal member in the screw portion is in a molten state, a linear portion being linear in a plan view and continuous with the screw portion is formed in which a metal member is melted by scanning of the spot so as to be separated from the screw portion.

This steel sheet is a steel sheet (100) formed by causing end surfaces of a first sheet material (111) and a second sheet material (113) to abut each other in an in-plane direction and welding the first sheet material (111) and the second sheet material (113) via a strip-shaped welded part (115), and in which a softened part (120) that is softened more than other parts in the welded part (115) is formed in at least a part of the welded part (115), and on a first end surface of the steel sheet in which an end part of the welded part (115) in a longitudinal direction is formed, a region in which the softened part (120) is not formed is provided in at least a part of the end part of the welded part (115) in the longitudinal direction, and a maximum value of a depth of the softened part (120) in a sheet thickness direction is, as a ratio to a sheet thickness of the steel sheet (100), 50% or less.

A method for laser welding two workpieces includes arranging a first workpiece of a thickness D1 and a second workpiece of a thickness D2 on top of one another so that the first workpiece and the second workpiece overlap in a region of overlap. Each of D1 and D2 is 400 μm or less. The method further includes melting, using a laser beam guided along a weld seam, a material of the first workpiece over an entirety of the thickness D1 and a material of the second workpiece over only a partial thickness TD of the thickness D2 in the region of overlap, from a side of the first workpiece. The laser beam generates a vapor capillary that extends to a capillary depth KT into the first workpiece or into the first workpiece and the second workpiece, where 0.33*EST≤KT≤0.67*EST, with EST being a weld depth EST=D1+TD.

A method for manufacturing a dissimilar material joint structure by joining a steel material and an aluminum or aluminum alloy material having a low-temperature spray coating made of a metal powder capable of being joined to the steel material on at least a part of a surface of the aluminum or aluminum alloy material. The method includes overlapping the aluminum or aluminum alloy material and the steel material such that the low-temperature spray coating and the steel material face each other and emitting a laser beam from a steel material side. Where a region to be irradiated with the laser beam includes a first region where at least the steel material and the low-temperature spray coating are melted, and a second region where the steel material and the low-temperature spray coating are not melted in a peripheral portion of the first region.

Provided is a method of manufacturing a joined member by joining a first metal member and a second metal member, the method including: melting an end portion on a joining side of the first metal member, while the first metal member is disposed adjacent to at least a portion of the second metal member, by irradiating the heat source while scanning, the heat source irradiated to the end portion on the joining side of the first metal member has a central portion and a peripheral portion located at a periphery of the central portion and having energy intensity lower than that of the central portion, and in the peripheral portion, a length in a scanning direction of the heat source is longer than a length in a direction perpendicular or substantially perpendicular to the scanning direction of the heat source.

A method of joining electrical connections together includes evaluating at least one weld joint between at least two substrates, determining a mismatch between the at least two substrates, and welding the at least two substrates together with a multi-step welding process. The multi-step welding process includes compensating for the mismatch between the at least two substrates by welding on both sides but not overlapping a joint line between the at least two substrate with a first welding step and increasing melt volume and penetration depth of a weld between the at least two substrates with a second welding step.

A method of joining electrical connections together includes evaluating at least one weld joint between at least two substrates, determining a mismatch between the at least two substrates, and welding the at least two substrates together with a multi-step welding process. The multi-step welding process includes compensating for the mismatch between the at least two substrates by welding on both sides but not overlapping a joint line between the at least two substrate with a first welding step and increasing melt volume and penetration depth of a weld between the at least two substrates with a second welding step.

A cylindrical battery includes a bottom-closed cylindrical exterior package can which receives an electrode body. A lead connected to one of a positive electrode and a negative electrode of the electrode body is extended from the electrode body and is welded to a bottom portion of the exterior package can. When the bottom portion is viewed from the outside of the exterior package can, at least a part of the welding portion between the lead and the bottom portion formed by a molten mark is formed outside of a concentric circle of the bottom portion which has a diameter equivalent to the width of the lead.

Provided is a laser-weld manufacturing method. The method includes: providing a first component and a second component that are separated from one another by a gap, the gap having a depth and a width and at least one of the first component and the second component having a sacrificial edge-tab; exposing the sacrificial edge-tab to laser energy, the laser energy being sufficient to melt at least a portion of the sacrificial edge-tab; forming a melt-pool in the gap between the first component and the second component, the melt-pool including material from the melted portion of the sacrificial edge-tab; and solidifying the melt-pool to form a weld that joins the first component and the second component together.

Provided is a laser-weld manufacturing method. The method includes: providing a first component and a second component that are separated from one another by a gap, the gap having a depth and a width and at least one of the first component and the second component having a sacrificial edge-tab; exposing the sacrificial edge-tab to laser energy, the laser energy being sufficient to melt at least a portion of the sacrificial edge-tab; forming a melt-pool in the gap between the first component and the second component, the melt-pool including material from the melted portion of the sacrificial edge-tab; and solidifying the melt-pool to form a weld that joins the first component and the second component together.