A spot welded joint of at least two steel sheets is provided. At least one of the steel sheets presents yield strength above or equal to 600 MPa, an ultimate tensile strength above or equal to 1000 MPa, uniform elongation above or equal to 15%. The base metal chemical composition includes 0.05≤C≤0.21%, 4.0≤Mn≤7.0%, 0.5≤Al≤3.5%, Si≤2.0%, Ti≤0.2%, V≤0.2%, Nb≤0.2%, P≤0.025%, B≤0.0035%, and the spot welded joint contains a molten zone microstructure containing more than 0.5% of Al and containing a surface fraction of segregated areas lower than 1%, said segregated areas being zones larger than 20 μm.sup.2 and containing more than the steel nominal phosphorus content.

A method for resistance spot welding comprising the following successive steps: —providing at least two steel sheets with thickness (th) comprised between 0.5 and 3 mm, at least one of the sheets being a zinc or zinc-alloy coated steel sheet (A) with a tensile strength (TS) higher than 800 MPa and a total elongation (TEL) such as (TS)×(TEL)>14000 MPa %, wherein the composition of the steel substrate of (A) contains, in weight: 0.05%≤C≤0.4%, 0.3%≤Mn≤8%, 0.010%≤Al≤3%, 0.010%≤Si≤2.09%, with 0.5%≤(Si+Al)≤3.5%, 0.001%≤Cr≤1.0%, 0.001%≤Mo≤0.5% and optionally: 0.005%≤Nb≤0.1%, 0.005%≤V≤0.2%, 0.005%≤Ti≤0.1%, 0.0003%≤B≤0.005%, 0.001%≤Ni≤1.0%, the remainder being Fe and unavoidable impurities, —performing resistance spot welding of the at least two steel sheets for producing a weld with an indentation depth (IDepth) on the surface of said steel sheet (A) such as: 100 μm≤(IDepth)≤18.68 (Zn.sub.sol)−55.1, wherein (IDepth) is in micrometers and wherein Zn.sub.sol is the solubility of Zn in the steel of sheet (A) at 750° C., in weight %.

Proposed is a resistance spot welding method to join parts to be welded which are a plurality of overlapping metal sheets, including: dividing a current pattern into two or more steps for welding; before actual welding, performing test welding; and subsequently, as actual welding, performing adaptive control welding, in which the two or more steps for welding include a step of securing a current path between the sheets directly below the electrodes and a subsequent step of forming a nugget having a predetermined diameter, and a welding interval time is provided between these steps. This method thus yields a good nugget without causing splashing even under special welding conditions.

A cutting blade for vegetation is provided for example for use in a straw chopper or rotary mower. The blade body includes a first base material and at least one hard surface bead formed on at least one surface of the base material extending up to a cutting edge of the base material. Beads can be applied longitudinally by the heat energy from the cladding laser system to form pockets so that the blade is serrated by the pockets when supplied with additional wear increasing the pockets to maintain the serrations. The chamfered side face of the blade body forming the cutting edge can also be formed using heat energy from the same laser cutting and cladding system.

There is provided a an apparatus for manufacturing a display device. An apparatus for manufacturing a display device comprises a body generating ultrasonic vibration; and a horn including a horn body portion connected to the body and amplifying the ultrasonic vibration and a horn tip portion connected to the horn body portion and applying the ultrasonic vibration onto a bonding object, wherein the horn body portion includes at least one body groove surrounded by the horn body portion and completely penetrating the horn body portion in a thickness direction from the surface of the horn body portion.

A processing apparatus processes an object by irradiating the object with a processing light, and includes: a combining optical system that combines an optical path of the processing light from the processing light source and an optical path of a first measurement light from a measurement light source; an irradiation optical system that irradiates the object with processing light and the first measurement light through the combining optical system; a position change apparatus that changes a position of the irradiation optical system relative to the object; an imaging apparatus a position of which is changed together with the irradiation optical system and which captures an image of the object; and a detection apparatus that detects, through the irradiation optical system and the combining optical system, a second measurement light generated from the object due to the first measurement light with which the object is irradiated through the irradiation optical system.

A tailor-welded blank is made of two steels, one steel of Alloy A and one steel of Alloy B. Alloy A comprises 0.10-0.50 wt % C, 0.1-0.5 wt % Si, 2.0-8.0 wt % Mn, 0.0-6.0 wt % Cr, 0.0-2.0 wt % Mo, 0.0-0.15 wt % Ti, and 0.0-0.005 wt % B and wherein Alloy B comprises 0.06-0.12 wt % C, 0.1-0.25 wt % Si, 1.65-2.42 wt % Mn, 0.0-0.70 wt % Cr, 0.08-0.40 wt % Mo, 0.0-0.05 wt % V, and 0.01-0.05 wt % Ti.

A method for manufacturing a stator for a rotary electric machine including: a process of abutting, on each other, tip end parts of one coil piece and an other one coil piece for forming a stator coil of a rotary electric machine; and a welding process of irradiating a welding target location regarding the tip end part having been abutted with a laser beam having a wavelength of 0.6 μm or less, in which in the welding process, the laser beam is generated for every pulse oscillation in a laser oscillator in a mode of having a laser output of 3.0 kW or more, and in at least a part of a period during one pulse oscillation, the laser beam is moved so that an irradiation position changes linearly parallel to an abutment surface of the tip end part.

A busbar includes: a plurality of members that are platy; and a welding area in which two of the members are welded, the welding area being linear and extending in a first direction, the welding area being provided approximately between both ends of at least one of the two members in the first direction.

A method of removing a plurality of portions of a black layer of an electrical conduit for a photovoltaic cell is disclosed. The method includes providing a mandrel having the electrical conduit electroformed in the mandrel. The electrical conduit is formed in a preformed pattern on an outer surface of the mandrel. The electrical conduit has the black layer with a black layer thickness on a side opposite of the outer surface of the mandrel. A beam of a laser is controlled toward the black layer of the electrical conduit. The beam is characterized by laser parameters. The beam of the laser removes the plurality of portions of the black layer on the electrical conduit. Each removed portion of the plurality of portions of the black layer has a thickness equal to the black layer thickness, and a portion area of 5 mm.sup.2 to 20 mm.sup.2.