A system and method provide gasless, mechanized, field welding of an exterior of a tubular structure such as a pipeline, without the need for an enclosure. An embodiment consolidates some of the welding equipment on a skid for ease of transport to and from a remote worksite. The gasless weld may be achieved despite the presence of wind, by precisely controlling an arc voltage as disclosed. The footprint and weight of the system may be minimized, along with the associated labor, expense, and environmental impact otherwise incurred by conventional welding techniques using enclosures.

An orbital welder for welding together two pipes to be welded. The welder includes a fall brake for preventing a freefall of the welder. The welder includes a spatter shield for preventing dust from entering the outer housing and fowling sensitive machine components. The welder includes a torch assembly with manual adjustments. The welder includes an automatic lead/lag adjustment and control of that adjustment during a welding operation to automatically transition from a first weld zone to a second weld zone.

Provided is a novel method for improving fatigue strength, which is applicable to any small portion that is covered with another member. A method for improving fatigue strength according to the present invention includes: disposing an aid (3, 15) to be opposed to an processing object (2A, 2B, 6) on which a fatigue strength improving process is performed, the aid being configured to assist the improving process; and generating sparks between the aid (3, 15) and the processing object (2A, 2B, 6).

A system for manufacturing boiler tubes includes a first spindle for receiving a first tube having a first weld preparation, a second spindle for receiving a second tube having a second weld preparation, the first spindle and the second spindle being rotatable synchronously, and a welding device having a first weld head. The welding device is configured to automatically weld the first tube to the second tube according to a control routine stored in memory to produce a boiler tube.

An automated welding system includes a welding robot and control circuitry. The welding bug robot includes a welding torch. The welding bug robot is configured to move on a track disposed around a circumference of a first pipe and perform a root pass welding operation at a joint between the first pipe and a second pipe. The control circuitry is configured to control movement of the welding bug robot around the circumference of the first pipe, apply a high energy welding phase via the welding torch to establish a first root condition, and apply a low energy welding phase via the welding torch to establish a second root condition.

A system for manufacturing boiler tubes includes a first spindle for receiving a first tube having a first weld preparation, a second spindle for receiving a second tube having a second weld preparation, the first spindle and the second spindle being rotatable synchronously, and a welding device having a first weld head. The welding device is configured to automatically weld the first tube to the second tube according to a control routine stored in memory to produce a boiler tube.

An automated welding system includes a welding robot and control circuitry. The welding bug robot includes a welding torch. The welding bug robot is configured to move on a track disposed around a circumference of a first pipe and perform a root pass welding operation at a joint between the first pipe and a second pipe. The control circuitry is configured to control movement of the welding bug robot around the circumference of the first pipe, apply a high energy welding phase via the welding torch to establish a first root condition, and apply a low energy welding phase via the welding torch to establish a second root condition.

A system and method provide gasless, mechanized, field welding of an exterior of a tubular structure such as a pipeline, without the need for an enclosure. An embodiment consolidates some of the welding equipment on a skid for ease of transport to and from a remote worksite. The gasless weld may be achieved despite the presence of wind, by precisely controlling an arc voltage as disclosed. The footprint and weight of the system may be minimized, along with the associated labor, expense, and environmental impact otherwise incurred by conventional welding techniques using enclosures.

A mobile hardbanding system that uses PTA welding to perform hardbanding on drill string sections at the well site. The inventive system allows alternate use of PTA and MIG welding. Both a PTA torch and a MIG torch are provided. Changing from one type of welding to the other is simplified by including separate electrical, gas, and cooling conduits for each torch. The torch not in use is parked in the welding compartment near the weld box. The powder hopper for the PTA welding assembly may be mounted on a swivel arm so that it can be moved out of the way when the MIG torch is in use.

A submerged arc welded joint in a high-Mn content steel material that can be formed with reduced occurrence of hot cracking during the welding process and has high strength and excellent cryogenic impact toughness. In the welded joint, the high-Mn content steel material has a chemical composition including, by mass %, C: 0.10 to 0.80%, Si: 0.05 to 1.00%, Mn: 18.0 to 30.0%, P: 0.030% or less, S: 0.0070% or less, Al: 0.010 to 0.070%, Cr: 2.5 to 7.0%, N: 0.0050 to 0.0500%, and O: 0.0050% or less, the balance being Fe and incidental impurities, and a weld metal has a chemical composition including C: 0.10 to 0.80%, Si: 0.05 to 1.00%, Mn: 15.0 to 30.0%, P: 0.030% or less, S: 0.030% or less, Al: 0.100% or less, Cr: 6.0 to 14.0%, and N: 0.100% or less, the balance being Fe and incidental impurities.