A welding head for a welding apparatus, the head comprising an outer face attachable to a welding device such as an electron beam gun or laser, an inner face sealable to a workpiece, and an outer sealing ring and an inner sealing ring situated within the inner face and disposed on either side of an evacuatable region, wherein the inner face has a teardrop-shaped profile. Outer and inner sealing rings can be inflatable or formed from different materials, the outer sealing ring being formed from a material with a Shore hardness of between 50 to 70 and the inner sealing ring being formed from a material with a Shore hardness of 20 to 40. A bridging seal can extend from within the inner sealing ring to the outer sealing ring.

A welding head for a welding apparatus, the head comprising an outer face attachable to a welding device such as an electron beam gun or laser, an inner face sealable to a workpiece, and an outer sealing ring and an inner sealing ring situated within the inner face and disposed on either side of an evacuatable region, wherein the inner face has a teardrop-shaped profile. Outer and inner sealing rings can be inflatable or formed from different materials, the outer sealing ring being formed from a material with a Shore hardness of between 50 to 70 and the inner sealing ring being formed from a material with a Shore hardness of 20 to 40. A bridging seal can extend from within the inner sealing ring to the outer sealing ring.

The present disclosure includes a laser welding method in which a joint surface between a plurality of workpiece members is welded by radiating laser beam LB, and a locus of laser beam LB is controlled so as to perform wobbling scanning Sw by a combination of scanning motion Sa moving along first direction x parallel to the joint surface and swing motion Sb including first swing component Bx along first direction x and second swing component By along second direction y perpendicular to first direction x, the method including a defect determination step of determining occurrence of a welding defect; and an output control step of increasing or decreasing an output of laser beam LB when laser beam LB is radiated again toward the welding defect in a case where the welding defect occurs.

Provided is an apparatus for coating a girth weld and a cutback region surrounding said girth weld, said apparatus having lateral travel at least equal to the length of the cutback region and circumferential rotational travel around the pipe. The apparatus can provide a multiple component coating accurately and safely, without the need for solvent flushing of the apparatus.

Methods for welding a particle-matrix composite body to another body and repairing particle-matrix composite bodies are disclosed. Additionally, earth-boring tools having a joint that includes an overlapping root portion and a weld groove having a face portion with a first bevel portion and a second bevel portion are disclosed. In some embodiments, a particle-matrix bit body of an earth-boring tool may be repaired by removing a damaged portion, heating the particle-matrix composite bit body, and forming a built-up metallic structure thereon. In other embodiments, a particle-matrix composite body may be welded to a metallic body by forming a joint, heating the particle-matrix composite body, melting a metallic filler material forming a weld bead and cooling the welded particle-matrix composite body, metallic filler material and metallic body at a controlled rate.

Methods for welding a particle-matrix composite body to another body and repairing particle-matrix composite bodies are disclosed. Additionally, earth-boring tools having a joint that includes an overlapping root portion and a weld groove having a face portion with a first bevel portion and a second bevel portion are disclosed. In some embodiments, a particle-matrix bit body of an earth-boring tool may be repaired by removing a damaged portion, heating the particle-matrix composite bit body, and forming a built-up metallic structure thereon. In other embodiments, a particle-matrix composite body may be welded to a metallic body by forming a joint, heating the particle-matrix composite body, melting a metallic filler material forming a weld bead and cooling the welded particle-matrix composite body, metallic filler material and metallic body at a controlled rate.

A method of joining two ferrous alloy component parts. The method includes hot metal casting a portion of a first ferrous alloy component part onto a first joining surface of a low carbon intermediate element; friction fitting a joining surface of a second ferrous alloy component part against a second joining surface of the low carbon intermediate element; and fusion welding with a concentrated energy source the intermediate element to the second ferrous alloy component part. The hot metal casting includes flowing a molten ferrous alloy onto the textured first joining surface, wherein the molten ally encompasses tabs extending from the first joining surface and filling apertures defined in the intermediate element. Then cooling the molten ferrous alloy such that a metallurgical and mechanical bond is formed between the portion of the first ferrous alloy component part and the first joining surface of the low carbon intermediate element.

To increase strength without any weight increase due to a thickness increase and without causing the machining problem in half-blanking, an external gear and an internal gear are ring-shaped gears, and external teeth and internal teeth each have a tooth width substantially corresponding to the thickness of an outer circumferential surface of the external gear or an inner circumferential surface of the internal gear. The external gear and the internal gear are ring-shaped gears, that is, each can be formed through the punching of a plate, and strength resulting from the engagement of the external teeth and the internal teeth corresponds to strength resulting from the thickness of the material plates forming the external gear and the internal gear. Accordingly, the external teeth and the internal teeth can have a wider tooth width, achieving higher strength than when half-blanking is used.

Disclosed is a manufacturing method of a welded pipe, which includes: bending a stainless steel strip while conveying the stainless steel strip in one direction to thereby form a pipe; and welding a butting part of the formed pipe.

Disclosed is a manufacturing method of a welded pipe, which includes: bending a stainless steel strip while conveying the stainless steel strip in one direction to thereby form a pipe; and welding a butting part of the formed pipe.