The present invention provides a joining method including: a butting step in which a rear face of a first metal member having a recessed groove on its front face is butted against an end face of a second metal member to form a butted portion; and a friction stir step in which a stirring pin of a rotary tool is inserted in the recessed groove so as to be relatively moved therealong for joining the butted portion by friction stir. The diameter of the shoulder portion is set to be smaller than a width of the recessed groove, and in the friction stir step, the butted portion is joined by friction stir in a state that the shoulder portion is spaced from a bottom face of the recessed groove while the shoulder portion holds burrs generated from the first metal member.

A structural member is disclosed. The structural member includes a body having a first surface, a second surface, and an end surface at an end portion of the structural member. The end portion of the structural member includes a root protrusion extending radially outward from the second surface of the structural member along a root protrusion radius to an outer end of the root protrusion to define a root protrusion height extending from the second surface of the structural member to the outer end of the root protrusion. The root protrusion further includes a root protrusion width extending between an inner edge and an outer edge of the outer end of the root protrusion. The root protrusion radius, the root protrusion height, and the root protrusion width are configured to define a stress protected weld root region isolated beyond and away from a root stress flow path propagated through the body of the structural member.

Provided are a laser-welded structure and a laser welding method for a cover and a housing ensuring high reliability and suppressing changes in characteristics due to burrs protruding into a subpassage of the flow sensor. To this end, this flow sensor is provided with a housing, a cover, a circuit chamber sealed between these and housing electronic components or wiring, and a subpassage through which the fluid flows that is to be sensed, and is characterized in that there are projections provided on both ends of the joining section of the cover where the housing and the cover are laser-welded, and the height of the projection on the subpassage side is greater than the height of the projection on the side opposite of the subpassage.

The present invention is a weld metal formed by gas shielded arc welding using a flux cored wire, the welded metal having a predetermined chemical composition, residual austenite particles being present in an amount of at least 2500 particles/mm.sup.2, and the volume fraction of residual austenite particles being at least 4.0%.

A welded blank assembly includes a capping material in a weld region of the assembly. The capping material can help protect a weld joint joining first and second sheet metal pieces together. At least one of the sheet metal pieces has a coating material layer that is removed prior to forming the weld joint so that the coating material does not contaminate the weld joint. The removed coating material can be collected before the weld joint is formed and reapplied as part of the capping material after the weld joint is formed, effectively changing the coating material from a potential weld contaminant to a weld joint protectant. The capping material may also include additional material from a source other than the coating material layer.

A method for forming a brazed joint between a first part having a first surface and a second part having a second surface may comprise applying at least two beads of braze filler at either of the first surface and the second surface, and assembling the first surface and the second surface to define a shiplap interface therebetween. The shiplap interface may terminate at a first terminus and a second terminus, and may include a first cavity and a second cavity. One of the beads of braze filler may be localized at the first cavity and the other may be localized at the second cavity. The method may further comprise melting each of the beads of braze filler to a braze liquid, and allowing the braze liquid to flow through the shiplap interface from the first cavity towards the first terminus, and from the second cavity towards the second terminus.

A square battery includes a battery can surrounded by four side wall portions, and having an upper end portion on one side in a height direction of the side wall portions opened and a bottom portion in a lower end portion on the other side in the height direction, and a battery lid welded to the upper end portion to seal the battery can, wherein between the battery can and the battery lid, a lateral boundary surface in a lateral direction crossing the height direction of the side wall portions and a vertical boundary surface in a vertical direction crossing the lateral boundary surface and along the height direction of the side wall portions are formed, at least a part of the lateral and vertical boundary surfaces being welded by a laser radiated in the vertical direction along the height direction of the side wall portions.

A friction stir welded structure includes first and second members. The first member has a base defining opposed first and second surfaces, and spaced first and second walls extending outwardly from the second surface of the base to define a receptacle therebetween. The second member includes an elongate rib extending from a root portion to a first tip portion, the root portion having a uniform root portion thickness and the first tip portion having a first tip portion thickness not greater than the root portion thickness. The first tip portion is sized for insertion into the receptacle and shaped conformally with the receptacle so that the first tip portion engages a closed end of the receptacle. A friction stir weld joint extends through the base and at least portions of the first and second walls of the first member and into the first tip portion of the second member, thereby to join the first and second members.

A joining method is capable of suitably joining metal members of different kinds. The joining method includes a step of preparing a first metal member having a first upper surface, a first lower surface and a first inclined surface connecting the first upper surface and the first lower surface, and a second metal member having a second upper surface, a second lower surface and a second inclined surface connecting the second upper surface and the second lower surface. The second metal member has a higher melting temperature than the first metal member. A butting interface is formed by butting the first inclined surface and the second inclined surface. The first and second metal members are joined by moving a rotary tool along the butting interface while the rotary tool is inserted from the first upper surface and a stirring pin is in contact with the first metal member.

A method and system for forming a weld joint using additive manufacturing is disclosed. The method and system involve providing a non-additive manufactured metal structure that includes a first end portion, a second end portion opposite the first end portion, and a middle portion between the first end portion and the second end portion. The method and system further involve increasing an effective sectional area of the first end portion by additive manufacturing a metallic geometric structure substantially permanently on the first end portion of the non-additive manufactured metal structure, without creating any fatigue-sensitive notches. One or more free edges of the additive manufactured metallic geometric structure form a weld interface at which to form the weld joint to fix the non-additive manufactured metal structure to another metal or metallic structure.