Art for spot welding able to suppress penetration of hydrogen, one of the factors behind delayed fracture, at the time of spot welding, that is, a spot welding method in which at one or both of the surfaces of the steel sheets becoming the facing surfaces of the overlaid steel sheets, a location where the steel sheets contact each other to form a contact part at the time of initial squeezing of the spot welding is worked in advance to form a plurality of lines running through the contact part and connected to the outside of the contact part and the spot welding is performed at the location of the contact part and also a steel sheet in which the plurality of lines are formed in advance at the location becoming a contact part when steel sheets contact each other at the time of initial squeezing in the spot welding.

A machining head emits a laser beam for cutting sheet metal of stainless steel. A moving mechanism moves the machining head relatively to a surface of the sheet metal. A beam vibrating mechanism vibrates a laser beam in a parallel direction with a cutting advancing direction of the sheet metal. In a machining condition database, a single specific vibration frequency at which cutting of the sheet metal is possible is set to a maximum moving velocity at which cutting of the sheet metal is possible, and a plurality of vibration frequencies from a maximum frequency to a minimum frequency at which cutting of the sheet metal is possible are set to a moving velocity more than or equal to a minimum moving velocity and less than the maximum moving velocity at which cutting of the sheet metal is possible.

The present invention includes a laser-welded lap joint including a weld zone formed by laser lap welding in a lapped portion including a plurality of lapped steel sheets. The weld zone includes a main weld zone that penetrates the steel sheets in the lapped portion and a final weld zone formed at one end of the main weld zone and having a crater, and the weld zone satisfies formulas (1) to (4):
L≥15.0;  (1)
10.0≥L2≥2l.sub.c;  (2)
t1≥2d.sub.c;  (3)
w.sub.c>d.sub.c  (4).

The present disclosure provides a printer system based on high power, high brightness visible laser source for improved resolution and printing speeds. Visible laser devices based on high power visible laser diodes can be scaled using the stimulated Raman scattering process to create a high power, high brightness visible laser source.

Apparatuses and methods for repairing a defect in a nuclear reactor are provided. The apparatus includes a body for insertion in a tubular structure, the body includes: an end effector having a weld torch operable to deposit weld material by forming molten weld droplets and depositing the weld droplets the tubular structure. A drive unit includes a brace for selectively anchoring against said tubular structure; at least one linear actuator for moving the apparatus relative to the brace; and a rotational actuator coupled to rotate the weld torch. The method includes inserting a repair apparatus into tubular structure of the nuclear reactor; moving the repair apparatus to a defect location; depositing a protective weld layer over the defect by sequentially depositing weld droplets atop a weld pool on the tubular structure, wherein the protective weld layer bonds to the tubular structure surrounding the defect.

A pulley assembly having a body, a shaft mount and a plurality of bolts is disclosed. The body is aligned to the shaft mount by providing a tight tolerance between a shoulder portion of the bolt and a neck portion of a counter sunk hole formed in the body. Additionally, an outer surface of the body may have a pattern of friction lines or patches formed by fusing particulate matter to the outer surface with heat generated by a laser beam.

A tube assembly includes at least first and second tubes configured for coupling at respective ends. The first and second tubes each include a base material, and a weld interface at the respective end. The weld interface is proximate to an inner diameter and an outer diameter of the first and second tubes, and includes a weld interface segment extending therebetween. A work hardened weld assembly couples the base material of each of the first and second tubes. The work hardened weld assembly includes a weld fusion zone between the weld interfaces of the first and second tubes and the weld interface segments of the first and second tubes. The weld fusion zone is work hardened and at least the weld interface segments of the first and second tubes are work hardened between the work hardened weld fusion zone and the base material of the first and second tubes.

A fastening inclusion is provided and includes a hard point made of coalesced metal sheets, metal or fiber flanges extending from edges of the hard point, and a fastener arranged on the hard point. The fastening inclusion can be incorporated into a fiber reinforced polymer structure by interleaving the flanges with fiber reinforced resin plies, and then curing the fiber reinforced plies to form a composite structure. The fastener on the hard point may be used for mechanically connecting the composite structure to a separate component, such as a metal component on a vehicle.

A control device controls a beam vibrating mechanism to vibrate a laser beam in a C-shaped vibration pattern in which a beam spot is moved from a first irradiation position at a front end in a cutting advancing direction to a second irradiation position at a rear side and displaced in an orthogonal direction to the cutting advancing direction, and is moved from the second irradiation position to a third irradiation position at a front end and displaced in the orthogonal direction to the cutting advancing direction, and movement from the first irradiation position to the third irradiation position via the second irradiation position, and movement from the third irradiation position to the first irradiation position via the second irradiation position are repeated. The control device performs control to cut the sheet metal by causing beam spots in the first to third irradiation positions to overlap one another.

A grain-oriented electrical steel sheet according to an embodiment of the present invention includes: a groove on a line formed on one surface of an electrical steel sheet in a direction crossing a rolling direction; and a thermal shock portion on a line formed on one surface of the electrical steel sheet in the direction crossing the rolling direction, wherein a distance between the groove and the thermal shock portion is 1 mm or less.