Provided is a flux-cored wire which is excellent in welding activity in all position welding, and excellent in the strength and low-temperature toughness of weld metal as welded (AW) and after PWHT. The flux-cored wire contains the proper amount of C, Si, Mn, Ni, B, Mg, V, Ti oxide, metal Ti, Al oxide, metal Al, Si oxide, metal fluoride, P and Nb.

Flux-cored wire for gas shielded arc welding

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.

A method and system for automatically filling the narrow gap between facing end walls of adjacent first and second railway rails (12) by depositing vertically spaced layers of molten metal in the gap (g) with an electric arc welding torch (30) using a robotic mechanism (50) that moves the torch in a pattern controlled by a low level robotic execute program from a spatial position to a next spatial position, said method and system comprising: constructing a data array for a specific gap, said array constituting a series of positions making up an idealized progression of said torch to fill said gaps in vertically spaced layers made up of multiple positions, each of said fixed positions identified by at least four coordinates, including (1) at least x, y, and z, (2) the layer in which said position is a part and (3) the welding parameters to be executed while said torch moves toward the next position; outputting data relating to a specific position from said data array; processing said welding parameters associated with said outputted data using said robotic execute program; then, outputting the new fixed data relating to the next position in said series of points; processing said welding parameters associated with said new data using said robotic execute program; and, repeating said outputting and processing acts until said positions in said data array relating to a specific layer have been processed Thereafter the method or system repeats the layer or processes the next layer comprising multiple stored positions

Method and system for welding railroad rails

A welding system (10) which allows a single welding operator to perform quick, easy and high quality vertical welds comprises a welding fixture (12) with a pair of opposing, positionally adjustable welding shoes, and lock screws for attaching to a workpiece (56) such as an I-beam. Welding fixture (12) is located adjacent the end of an articulating boom (20), and includes a welding torch (14) and oscillator (48). A rotary straight wire feeder (18) removes the cant and helix from welding wire as it is fed to the welding torch (14). The welding torch (14) prevents welding wire from fusing to a guide tube. A distributed welding control system comprising a plurality of controller modules (46, 48, 50, and 52) is interfaced with a common bus (54) and allows a welding operator to program automated welding cycles for various welding operations. The welding system (10) is particularly useful for installing stiffener plates (58) onto structural beams (56).

Welding system and method

A rail restraining (1) and weld delivery device (100) uses a frame for supporting a welding head with a clamp (3) for restraining a first rail end and a second rail end and a base twist assembly (17) for aligning said first end and second end. An interconnected weld containment apparatus (290) pivotally connects to the clamp by use of a cam actuated linear pin (7). This arrangement is operable in an environment in which clearance between rails is about 7 to 11 inches and sufficiently compact that it may be operated from and carried in a truck based on a standard over the road truck.

Rail welding apparatus incorporating rail restraining device, weld containment device and weld delivery unit

In a method of automatically welding rails, welding of bottom portions of the rails is carried out as root pass welding of a first layer according to CO2 gas shielded arc weld technique, and as continuous multilayer welding of layers above the first layer according to CO2 gas shielded arc weld technique without discontinuing the welding of a second layer and upper layers. In welding of ankle portions (R2) of the rails, a flux is rapidly added to promptly shift to electroslag weld. Then, welding is conducted to head surfaces (R5) of the rails by continuing electroslag weld technique. This automatic welding method enables high efficiency field welding of rails, obviating the need for any complicated switching operation of the electric power source and use of several kinds of welding materials.

Method of automatically welding rails

PURPOSE:To execute the welding with stable arc sensing by dissolving such problems as the detection of a fluctuation of a gap and the constant control of height of a bead by a welding speed, which are necessary for groove width profiling of arc sensing by consumable electrode type arc welding CONSTITUTION:In the consumable electrode type arc welding method in which an automatic welding machine which uses a digital servomotor for driving a running truck controls a welding speed and oscillation width in accordance with a fluctuation of a gap while executing successively arc sensing for a groove and one-layer/one-pass welding is executed while executing the control so that height of a bead becomes constant, this consumable electrode type arc welding method constitutes a characteristic feature of a fact that the oscillation width correction amount is controlled in proportion to a speed pulse rate correction amount of the running truck Especially, the welding accuracy of thick plate welding which necessitates multi-layer welding is improved, the welding process is automatized, and it makes a great contribution to robotization

Consumable electrode type arc welding method

PURPOSE:To provide a wire which provides excellent low temp. toughness in welding at a large heat input in a titled composite wire consisting of a steel sheath and a flux packed therein by constituting the flux at the specific component ratios with respect to the wire. CONSTITUTION:A composite wire for electrogas arc welding consisting of a steel sheath and a flux filled therein is prepd. in such a way that the flux contains at least, by the total weight of the wire, 0.2-1.0% CaF2, 0.3-1.0% Li2CO3. 0.2- 1.0% Si, 1.0-2.0% Mn, 0.1-0.5% Mo, 0.1-0.3% Ti, 0.002-0.010% B, and if necessary, 0.1-0.4% Mg and/or 0.5-5.0% Ni. Then excellent low temp. toughness is provided in welding at a large heat input of about >=100KJ/cm.

Composite wire for electrogas arc welding

PURPOSE:To realize a stable AC rectangular wave plasma arc by providing the zero voltage time for preventing an interphase short between the positive and negative components of an output voltage rectangular wave, adjusting the ratio and frequency of the positive and negative components and adequately controlling a no-load voltage. CONSTITUTION:A plasma welding equipment sets the rectangular wave signal of a rectangular wave oscillating circuit 6 at the necessary straight and negative polarity ratio by a straight and negative polarity ratio adjusting circuit 5. An interphase short preventing circuit 7 provides a zero voltage time between the positive and negative components in order to prevent the interphase short of the semiconductor element of the inside of an invertor circuit 3. In a slight term while the circuit 7 works, a high voltage is induced instantaneously with the DC power source 1 having a high no-load voltage and the reactance component of a plasma arc 11. A no-load adequate voltage control circuit 2a and adjustor 2b adequately control the no-load voltage of the power source 1 to prevent the breakdown of the semiconductor element of each circuit. In this way a stable AC rectangular wave plasma arc can be realized.

Plasma arc welding method using ac rectangular wave

PURPOSE:To form a fine penetration bead and to obtain a stable weld bead height by maintaining constant the distance between a welding torch and the surfaces of materials to be welded and controlling the welding speed according to a variation of a welding current value at the groove center. CONSTITUTION:A heat resistant backing material 3 is put on the rear of base metals 1 and 2 abutted on each other via a single V groove and a welding wire 13 is fed at a constant speed from the surface side via a gas shielded nozzle 14 of the welding torch 12 and weld metal 16 is formed by a welding arc 15. In the above-mentioned one-side welding method of the flat butt welding position, the distance between the above-mentioned welding torch 12 and the surfaces of the materials to be welded or the bead surface is detected by a range finder 26. The welding torch 12 height is controlled via a welding torch holder 11 by a welding torch lifting and lowering device 34 so that the detected output is maintained constant. Herewith, the variation of the welding current value at the groove width center is detected and the welding speed is controlled according to the difference of the above-mentioned variation with respect to a set reference value.

Fujiyama Hirohisa

Papers

Method of automatically welding rails

Consumable electrode type arc welding method

Composite wire for electrogas arc welding

Plasma arc welding method using ac rectangular wave

One-side welding method