Submerged arc welding torches and systems to resistively preheat electrode wire are disclosed. A disclosed example submerged arc welding torch includes: a first contact tip configured to transfer weld current and preheating current to the wire; a second contact tip configured to conduct the preheating current to the wire; an air-cooled first conductive body portion configured to receive the weld current and to conduct the weld current and the preheating current to the first contact tip; an air-cooled second conductive body portion configured to receive the preheating current and to conduct the preheating current to the second contact tip; and an insulator coupled between the first and second conductive body portions.

A submerged arc welding wire is provided that has a composition including, by mass %, C: 0.20 to 0.80%, Si: 0.15 to 0.90%, Mn: 15.0 to 30.0%, P: 0.030% or less, S: 0.030% or less, Cr: 6.0 to 15.0%, and N: 0.120% or less, the balance being Fe and incidental impurities. Where necessary, the wire may contain one or two selected from Ni and Mo, may further contain one, or two or more selected from V, Ti, and Nb, and may additionally contain one, or two or more selected from Cu, Al, Ca, and REM.

A submerged arc welding wire is provided that has a composition including, by mass %, C: 0.20 to 0.80%, Si: 0.15 to 0.90%, Mn: 15.0 to 30.0%, P: 0.030% or less, S: 0.030% or less, Cr: 6.0 to 15.0%, and N: 0.120% or less, the balance being Fe and incidental impurities. Where necessary, the wire may contain one or two selected from Ni and Mo, may further contain one, or two or more selected from V, Ti, and Nb, and may additionally contain one, or two or more selected from Cu, Al, Ca, and REM.

A metal cored wire for submerged arc welding, the wire comprising a steel sheath with a core comprising powders of: carbon in a range of about 0.3 wt. % to about 1.2 wt. %; silicon in a range of about 0.1 wt. % to about 3.0 wt. %; manganese in a range of about 9.0 wt. % to about 30 wt. %; chromium in an amount less than about 8 wt. %; nickel in an amount less than about 6 wt. %; molybdenum in an amount less than about 6 wt. %; tungsten in an amount less than about 5 wt. %; copper in an amount less than about 4 wt. %; niobium in an amount less than about 2 wt. %; vanadium in an amount less than about 2 wt. %; titanium in an amount less than about 2 wt. %; nitrogen in an amount less than about 0.4 wt. %; boron in an amount less than about 1 wt. %; at least one of: (i) sulfur in an amount less than about 0.3 wt. %; (ii) phosphorous in an amount less than about 0.03 wt. %; or a combination thereof; and the balance with iron.

The present invention relates to steel pipe excellent in toughness of the weld metal part at a low temperature obtained by submerged arc welding in the longitudinal direction from both the inside and outside surfaces having strengths of the X60 to X70 class. The steel pipe of the present invention is a pipe having weld zones welded in a longitudinal direction at an inside surface and outside surface, wherein the tensile strength of the base metal is 480 to 620 MPa, the weld metal has a predetermined composition of constituents, when % X expresses a content of an element X in the weld metal, Pcm defined by Pcm=% C+% Si/30+(% Mn+% Cu+% Cr)/20+% Ni/60+% Mo/15+% V/10+5% B is 0.2% or less, Ceq defined by Ceq=% C+% Mn/6+(% Cr+% Mo+% V)/5+(% Ni+% Cu)/15 is 0.35 to 0.45%, and defined by =(1.5(% O-0.89% Al)+3.4% N-% Ti)1000 is 20 to 40, and % Al/% O is 0.3 to 0.8.

The present invention relates to steel pipe excellent in toughness of the weld metal part at a low temperature obtained by submerged arc welding in the longitudinal direction from both the inside and outside surfaces having strengths of the X60 to X70 class. The steel pipe of the present invention is a pipe having weld zones welded in a longitudinal direction at an inside surface and outside surface, wherein the tensile strength of the base metal is 480 to 620 MPa, the weld metal has a predetermined composition of constituents, when % X expresses a content of an element X in the weld metal, Pcm defined by Pcm=% C+% Si/30+(% Mn+% Cu+% Cr)/20+% Ni/60+% Mo/15+% V/10+5% B is 0.2% or less, Ceq defined by Ceq=% C+% Mn/6+(% Cr+% Mo+% V)/5+(% Ni+% Cu)/15 is 0.35 to 0.45%, and defined by =(1.5(% O-0.89% Al)+3.4% N-% Ti)1000 is 20 to 40, and % Al/% O is 0.3 to 0.8.

A method includes monitoring a submerged arc welding (SAW) operation in real-time; determining, based on the monitoring and in real-time, a discrepancy between a desired weld parameter and an actual weld parameter of a weld resulting from the SAW operation; and in response to determining the discrepancy, controlling a power supply, which provides power for the SAW operation, to modify at least one of balance or offset of an alternating current (AC) welding power signal supplied for the SAW operation to compensate for the discrepancy.

Automated material welding including starting a welding operation, scanning a weld in-progress, creating a simulation of the weld in-progress, detecting a flaw in the weld in-progress according to the scanning and the simulation, remediating the weld in-progress, and completing the welding operation.

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.

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.