A welding tape for thermally connecting metal workpieces by fusion, wherein the welding tape in a cross section has an outwardly closing cover layer which comprises an inner cover layer and an outer cover layer, wherein in the transverse direction provision is made at least in side edge regions of the inner cover layer for adhesive layers by means of which the welding tape can be fastened to the workpieces to be connected, wherein in the interior of the cover layer provision is made for a self-combusting exothermic substance, which during ignition provides the thermal energy which is required for the welding, wherein a non-combustible heat shield is arranged exclusively between the exothermic substance and the outer cover layer, and wherein a welding additive is provided between the exothermic substance and the inner cover layer.

A gas-shielded arc welding method is disclosed and includes joining steel materials together by narrow-gap multilayer welding. A groove between the steel materials has an groove angle ? of 20? or less, and a root gap G (mm) that is a gap at a lower portion of the groove is 7 to 15 mm. Root pass is performed in one pass using a ceramic-made backing material at a welding current I (A) of 250 to 400 A and a welding voltage V (V) of 25 to 45 V while a value [Q/G] obtained by dividing a welding heat input Q (KJ/mm) computed using a prescribed formula by the root gap G (mm) is controlled within a range of 0.32 to 0.70.

Disclosed are an adaptive control method and equipment of arc swing in narrow gap welding. The control equipment is composed of an infrared camera system, a computer image processing system, an arc swing parameter control system, a bent-conducting-rod-type swing arc torch and the like. The infrared camera system acquires, in an external triggering manner, an infrared image of welding area when an arc is deviated towards the left or the right side wall groove, extracts information about the width of the groove in real time after image processing by a computer, and calculates an arc swing angle target value. The arc swing parameter control system controls a motor drive mechanism to rotate a bent conducting rod, and drives the welding arc to conduct circular arc swing according to the swing angle target value, thereby realizing the adaptive control for the arc swing angle according to changes of the groove width.

The invention described herein generally pertains to a system and method related to detecting a change in height during a welding operation and adjusting one or more welding parameters based on such detected change in height. In particular, a change in a height can be related to two or more revolutions on the workpiece in which the change is due to material being deposited onto the workpiece from the welding operation. Since the material deposited onto the workpiece changes the height of the electrode to the workpiece, one or more welding parameters can be adjusted for compensation. Specifically, an electrode speed can be adjusted to compensate for a change in the height, wherein the electrode speed is a rate that the electrode moves adjacent to the workpiece.

A shaft element of a turbomachine, in particular of a combined steam turbine, having at least two shaft subsegments integrally joined to each other by means of a weld, wherein different chemical and mechanical properties are inherent to the shaft subsegments, wherein the weld has a ratio of welding layer height to weld width of 1:14 to 1:2. A method produces a shaft element composed of two different materials having at least two shaft subsegments integrally joined to each other by means of a weld.

An infrared vision sensing detection method and device for narrow-gap weld seam deviation are provided. The device includes a shaking (or rotating) arc narrow-gap welding torch, an arc current sensor, a computer image processing system, and an infrared photographing system. The infrared photographing system includes an infrared camera which acquires an infrared image of a welding region in an external triggering manner when an arc shakes (or rotates) to a position closest to the left side wall or right side wall of a groove. After computer image processing, a welding wire position and a groove edge information is extracted in real time, and a weld seam deviation is calculated according to position changes of a welding wire relative to the left side wall and the right side wall of the groove, and the weld seam deviation is output. During pulsed arc welding, a signal in a base value period of the arc current pulse is detected by using the current sensor, thereby realizing welding image acquisition synchronized with the base value current period of the pulsed arc.

Disclosed are an infrared vision sensing detection method and device for narrow-gap weld seam deviation. The device includes a shaking (or rotating) arc narrow-gap welding torch, an arc current sensor (3), a computer image processing system (15), and an infrared photographing system. An infrared camera (11) acquires an infrared image of a welding region in an external triggering manner when an arc (1) shakes (or rotates) to a position closest to the left side wall or right side wall of a groove (9). After computer image processing, welding wire position and groove edge information is extracted in real time, and weld seam deviation is calculated according to position changes of a welding wire relative to the left side wall and the right side wall of the groove, and the weld seam deviation is output. During pulsed arc welding, a signal in a base value period of the arc current pulse is detected by using the current sensor, thereby realizing welding image acquisition synchronized with the base value current period of the pulsed arc. The device has a simple constitution, a wide application range, high weld seam detection precision, high environment adaptability, and high anti-interference capability.

A contact tip for hot-wire welder is provided that are adapted to operate in deep and narrow recessed gaps within a work piece. Contact tips in accordance with the current invention provide for an assembly having a body portion with a cavity and an extension portion which is inserted into the cavity. The extension portion is non-electrically conductive and allows the contact tip assembly to reach into deep, narrow grooves without worry of shorting the contact tip of the consumable.

A rail welding method and device are provided. The method includes: welding a bottom of rail, wherein welding is repeatedly performed along a first swing trajectory in a lengthwise direction of a weld seam, from one end of the bottom of rail to the other end of the bottom of rail; welding a waist of rail, wherein welding is repeatedly performed in the lengthwise direction of the weld seam along a second swing trajectory, from one end of the waist of rail, and the second swing trajectory is divided into two regions for respective welding in a width direction of the weld seam; and welding a head of rail, wherein welding is performed in the lengthwise direction of the weld seam along the first swing trajectory, between one end of the head of rail and the other end of the head of rail.

Disclosed are a narrow gap laser-TIG arc hybrid welding apparatus and method. The welding apparatus includes a welding gun body, a swing welding gun assembly, a welding wire feeding and heating assembly, and a gas conveying assembly; the swing welding gun assembly includes a welding gun rotating shaft, a stepper motor, a large gear, a pinion, an upper insulating sleeve, a lower insulating sleeve, a tungsten electrode clamp, and a tungsten electrode; the stepper motor is mounted on a motor connection seat; the pinion is mounted on the output shaft of the stepper motor; the large gear is mounted on the welding gun rotating shaft; the pinion is engaged with the large gear; the welding gun rotating shaft is mounted and positioned on the welding gun body; the tungsten electrode is mounted at the tail end of the welding gun rotating shaft by means of the tungsten electrode clamp.