A method and apparatus for welding include initiating a pulse welding process includes initiating a welding arc by providing CC type welding power, maintaining the arc by providing CV type power. Then, pulse type welding power is provided. The method and system can be used to start short circuit, or other welding processes by providing short circuit power, or welding power of a given mode, instead of providing pulse power. Also, in one alternative, a method and system of initiating a pulse, short circuit, or given welding process includes initiating a welding arc by providing CC type welding power at least until a pseudo-equilibrium for the arc is established. Then, providing welding power in a pulse, short circuit, or the given mode.

Method and apparatus for welding

An apparatus and method of short circuit arc welding two spaced ends of two pipe sections at a groove between the two pipe sections. The method and apparatus include the use of a cored metal electrode and moving the electrode toward the groove as the electrode is moved along the groove and about the outer peripheral surface of the pipe sections during the welding operation. The cored electrode is melted by an electric cycle which comprises a transfer portion and a plasma portion. The plasma portion is controlled to bridge the gap between the pipe sections for laying a root bead along the groove. The cored electrode is preferably a self-shielding electrode and includes alloying components in the core to form a root bead having a substantially similar composition as the composition of the two pipe sections. The apparatus and method has a selector to control the polarity of the individual cycles of a total welding procedure.

Short circuit welder

A flux-cored wire for gas shielded arc welding is described. The wire comprises a steel sheath and a flux composition filled in the steel sheath at a flux rate of 8 to 25 wt%. The flux composition comprises, based on the weight of the total flux, 10 to 30% of TiO₂, 0.1 to 0.6% of Na₂O provided that a ratio of TiO₂ and Na₂O is in the range of 20 to 100: 1, 0.01 to 2.0% of a metal fluoride calculated as F, and 0.005 to 0.4% of moisture. The composition may further comprise Bi₂O₃.

Flux-cored wire for gas shielded arc welding

A consumable welding element for arc welding comprising a steel sheath surrounding a compacted core containing metal alloying powders and an essentially 100% basic compound in an amount less than about 1.60% of the total weight of said element. The basic compound is calcium fluoride powder which is preferably in the range of about 0.1% to about 0.9% calcium fluoride powder by total weight of the element. As another feature the core of the element contains a specific agent for decreasing the amount of diffusible hydrogen in the weld metal. This new element may be a filler metal for TIG welding; however, it is preferably a consumable electrode for MIG welding.

Low hydrogen basic metal cored electrode

An apparatus and method of short circuiting arc welding two spaced ends of two pipe sections at a groove between the two pipe sections. The method and apparatus include the use of a cored metal electrode and moving the electrode toward the groove as the electrode is moved along the groove and about the outer peripheral surface of the pipe sections during the welding operation. The cored electrode is melted by an electric wave which comprises a transfer portion and a controlled melting portion. The melting portion is controlled to bridge the gap between the pipe sections for laying a root bead along the groove. The cored electrode is preferably a self-shielding electrode and includes alloying components in the core to form a root bead having a substantially similar composition as the composition of the two pipe sections.

Short circuit pipe welding

Basic metal cored electrode

In a consumable welding element for depositing a weld metal bead onto a steel workpiece with the diffusible hydrogen in the weld metal being less than 2.0 ppm, the oxygen of the weld metal being less than 0.040% by weight and the yield strength of the weld metal being greater than about 85,000 psi, there is provided an improvement wherein the weld metal is a steel alloy including, as a percentage by weight of the weld metal, 0.03-0.09% carbon, 2.5-4.0% manganese, 0.01-0.05% titanium, silicon less than about 1.0%, nickel less than about 2.0%, and oxygen less than about 0.035%.

Weld metal alloy for high yield strength and method of depositing same

The invention relates to a consumable welding element for depositing a weld metal bead on a steel workpiece containing less than 2.0 ppm of diffusible hydrogen and less than 0.04% by weight of oxygen in the weld metal and having a weld metal yield strength above about 5,950 kg/cm . According to the invention, the weld metal consists of a steel alloy containing, as a percentage of its weight, 0.03 to 0.09% carbon, 2.5 to 4.0% manganese and 0.01 to 0.05% titanium, with silicon being less than about 1.0%, nickel less than about 2.0% and oxygen less than about 0.035%. The invention also relates to a method of depositing the weld metal in the arc welding process.

Fink David A

Papers

Basic metal cored electrode

Low hydrogen basic metal cored electrode

Weld metal alloy for high yield strength and method of depositing same

High yield strength weld metal alloy and method for its deposition

Epositing said alloy