One embodiment of the present invention relates to a welded member obtained by overlapping portions of two sheets of base metal and performing fillet welding thereon using weld material, and provides a welded member having excellent fatigue strength of welded portion, and a method for manufacturing same, the welded member comprising base metal, a weld bead and root-reinforcing weld metal, wherein the base metal has a tensile strength of 780 MPa, the weld bead has a toe angle of 160 degrees or greater and the weld bead and the root-reinforcing weld metal have a Vicker's hardness of 280-320 Hv and a fatigue strength of 350 MPa or higher.

One embodiment of the present invention relates to a welded member obtained by overlapping portions of two sheets of base metal and performing fillet welding thereon using weld material, and provides a welded member having excellent fatigue strength of welded portion, and a method for manufacturing same, the welded member comprising base metal, a weld bead and root-reinforcing weld metal, wherein the base metal has a tensile strength of 780 MPa, the weld bead has a toe angle of 160 degrees or greater and the weld bead and the root-reinforcing weld metal have a Vicker's hardness of 280-320 Hv and a fatigue strength of 350 MPa or higher.

An exemplary embodiment of the present invention discloses an aluminum-based blank including: a first plated steel plate; a second plated steel plate connected to the first plated steel plate; and a joint connecting the first plated steel plate and the second plated steel plate at a boundary between the first plated steel plate and the second plated steel plate.

A wheel holding device holding a wheel including an annular-shaped core body and a plurality of free rollers rotatably supported by the core body includes a central member including an outer peripheral part capable of expanding and contracting in a radial direction. The central member holds the wheel with the outer peripheral part of the central member urging an inner peripheral part of the wheel radially outward. The central member may include a chuck, a plurality of bases which are radially movably supported by the chuck and form the outer peripheral part of the central member, and a plurality of urging members which urge the respective bases radially outward with respect to the chuck.

Provided is a method of manufacturing a battery module including a) aligning a first base material and a second base material, which are welding objects and housing members that are combined with each other to form an internal accommodating space in which a plurality of battery cells are accommodated and b) forming a welding joint portion including a bonding region and a surface region covering the bonding region by irradiating a contact surface between the first base material and the second base material with a laser, the bonding region and the surface region forming the welding joint portion having different microstructures due to different thermal history.

Provided is a battery module including a housing having an internal accommodating space and a plurality of battery cells located in the internal accommodating space, wherein the housing includes a welding joint portion in which a first base material of a first alloy and a second base material of a second alloy are welded, the welding joint portion includes a bonding region in which the first base material and the second base material are melt-bonded and a surface region covering the bonding region, and the bonding region and the surface region have different microstructures.

The invention provides an economical laser welding method for joining two metal materials with a fillet joint. The method reliably compensates for tolerances between the two materials and can be used in various light conditions and production environments. In addition, the method does not require additional equipment for purposes of seam tracking. Instead, the method includes oscillating a laser beam, for example in a “figure 8” pattern, while moving the laser beam laterally along an interface between the two materials. The width of the fillet joint is increased compared to the fillet joint that would be formed using a non-oscillating laser beam, and thus compensates for the tolerances. The width of the fillet joint depends on the oscillation amplitude of the laser beam, rather than the beam size.

The invention provides an economical laser welding method for joining two metal materials with a fillet joint. The method reliably compensates for tolerances between the two materials and can be used in various light conditions and production environments. In addition, the method does not require additional equipment for purposes of seam tracking. Instead, the method includes oscillating a laser beam, for example in a “figure 8” pattern, while moving the laser beam laterally along an interface between the two materials. The width of the fillet joint is increased compared to the fillet joint that would be formed using a non-oscillating laser beam, and thus compensates for the tolerances. The width of the fillet joint depends on the oscillation amplitude of the laser beam, rather than the beam size.

A method for monitoring and/or controlling in a closed loop a laser welding process for welding together two workpieces of metallic material includes, during the laser welding process, scanning a melt pool and/or a melt bead using an optical coherence tomography (OCT) measurement beam in at least one line scan, determining an actual geometry of the melt pool and/or the melt bead based on the at least one line scan, and setting at least one welding parameter controlled in the closed loop based on a deviation of the actual geometry from a target geometry of the melt pool and/or the melt bead.

A joining method including an overlapping step of overlapping a front surface of a first metal member and a back surface of second metal member such that the front surface is opposed to the back surface; and a welding step of performing a laser welding and a MIG welding by using a hybrid welding machine including a preceding laser welding unit and a following MIG welding unit, in which the laser welding is performed by emitting a laser beam onto a front surface of the second metal member, the MIG welding is performed on an inner corner portion formed by the front surface of the first metal member and an end surface of the second metal member, and a target position for the laser beam from the laser welding unit is located against the second metal member relative to a target position for a MIG arc by the MIG welding unit.