A cracked gas cooling heat exchanger includes a tube connection between an uncooled tube (1) and a cooled tube (2), having a cooled inner tube (3) enclosed by a jacket tube (4), with a tube intermediate space (5) for flowing cooling medium. A gas inlet header (11) has a GI tube inner part (12) and a GI tube outer part (13) and a cooling space (14) with an insulating layer (15). The GI tube outer part connects via a water chamber (6) to the jacket tube. The GI tube inner part faces the inner tube and is connected on a face (8) of the water chamber. A weld backing ring (16), between an end face (9) of the cooling space and a bottom face (8) of the water chamber, is in the insulating layer of the cooling space, arranged in a turn-out/groove (17) in the insulating layer.

A GTAW system and a welding method suitable for ultra-narrow gaps, and belongs to the technical field of narrow gap welding. The device includes a argon arc welding machine, a GTAW torch, a welding trolley, a wire feeding device, and a gas protection device. The GTAW torch includes a rotating motor, a rotating tungsten, a conductive system, and a gas supply system. The non-axisymmetric rotating tungsten is drived by the rotating motor through the central rotating shaft. The conductive system is used for connecting and supplying electric power from the argon arc welding machine, and the air supply system is used for providing shielding gas into the welding torch. The GTAW torch is fixed on the welding trolley, and the GTAW torch is moved by the welding trolley, and the wire feeding device moves synchronously with the welding torch.

A welding support block supports, from the rear surface of a joint to be welded, a weld pool created during a welding process. The welding support block comprises a block of metal and an outer layer of ceramic material providing a supporting surface. The ceramic material layer has a thickness between 0.25 mm and 1.5 mm. The metal material immediately beneath the ceramic material layer is made of steel. An internal line-up clamp for holding pipes in end-to-end alignment ready for welding may include multiple such welding support blocks. The use of such welding support blocks is particularly useful when laying a sour service carrying pipeline (high H.sub.2S content).

A welding support block supports, from the rear surface of a joint to be welded, a weld pool created during a welding process. The welding support block comprises a block of metal and an outer layer of ceramic material providing a supporting surface. The ceramic material layer has a thickness between 0.25 mm and 1.5 mm. The metal material immediately beneath the ceramic material layer is made of steel. An internal line-up clamp for holding pipes in end-to-end alignment ready for welding may include multiple such welding support blocks. The use of such welding support blocks is particularly useful when laying a sour service carrying pipeline (high H.sub.2S content).

A method for joining an additively-manufactured component includes welding a plurality of additively-manufactured components via a weld joint to fabricate an integral structure. The additively-manufactured components are built by repeatedly depositing a weld bead layer of a next layer on a weld bead layer formed of a weld bead obtained by melting and solidifying a filler metal by use of an arc, and the weld joint is built along with the deposition.

A stainless steel weldment and pad combined welding method includes steps of: (a) respectively processing and pairing butts of to-be-welded portions of two weldments, wherein, during pairing, inner walls of the two weldments are aligned at the same plane; the butts of the two weldments are opposed to form a V-shaped groove with an angle α; and between bottoms of the butts of the two weldments is kept a gap L of 2-4 mm; (b) providing a copper pad at the gap between the bottoms of the butts of the two weldments, wherein the copper pad closely attaches to the inner walls of the two weldments; (c) welding the V-shaped groove to form a root pass; and (d) removing the copper pad, and filling the root pass to be welded into a cover pass.

A stainless steel weldment and pad combined welding method includes steps of: (a) respectively processing and pairing butts of to-be-welded portions of two weldments, wherein, during pairing, inner walls of the two weldments are aligned at the same plane; the butts of the two weldments are opposed to form a V-shaped groove with an angle α; and between bottoms of the butts of the two weldments is kept a gap L of 2-4 mm; (b) providing a copper pad at the gap between the bottoms of the butts of the two weldments, wherein the copper pad closely attaches to the inner walls of the two weldments; (c) welding the V-shaped groove to form a root pass; and (d) removing the copper pad, and filling the root pass to be welded into a cover pass.

Method for producing a component system having a first component with a first component portion and a second component with a second component portion, including the following steps: connecting, in particular welding or soldering, the first component portion, which consists of an aluminum alloy, to the second component portion, which in particular consists of a naturally aged aluminum alloy, a copper alloy or an iron alloy, in particular a steel alloy, so as to form a connection seam; artificially aging the connection seam such that the yield strength of the connection seam is above the yield strength of the first component portion and/or of the second component portion; and deforming, in particular deep-drawing and/or stretch-drawing, the component system.

Method for producing a component system having a first component with a first component portion and a second component with a second component portion, including the following steps: connecting, in particular welding or soldering, the first component portion, which consists of an aluminum alloy, to the second component portion, which in particular consists of a naturally aged aluminum alloy, a copper alloy or an iron alloy, in particular a steel alloy, so as to form a connection seam; artificially aging the connection seam such that the yield strength of the connection seam is above the yield strength of the first component portion and/or of the second component portion; and deforming, in particular deep-drawing and/or stretch-drawing, the component system.

The invention relates to a method of making a steel Yankee cylinder 1 by welding a cylindrical shell 2 to two end walls 3, 4 such that the cylindrical shell 2 and the end walls 3,4 together form the Yankee cylinder 1. The welding operation is carried out exclusively from the outside of the Yankee cylinder 1 and in the welding operation is carried out as a butt welding operation in which a backing material 7 is used on the inside of the Yankee cylinder 1 such that, between each end wall 3, 4 and the cylindrical shell 1, a single weld bead 8 is formed which extends all the way between the opposing surfaces 5, 6 and completely fuses the opposing surfaces 5, 6 of each end wall 3, 4 and the cylindrical shell 2 respectively.