Abstract: A method of flash-butt resistance welding of a batch of like parts in pairs consists in that during flashing off of workpieces (1,2) they are brought apart or together depending on the resulting resistance obtained by comparison of the actual resistance between the workpieces (1,2) being welded with the specific short-circuit impedance of the welding circuit, which is determined during the upsetting of the preceeding pair of workpieces (1,2) after the welding current reaches a constant level.

Abstract: The disclosed process includes the steps of and upsetting the flashing parts being welded. The flashing is conducted with concurrent measurement of useful electric power and an electric parameter of the flashing process which is related to the power by a function which maximizes the useful power at a predetermined value of said electric parameter. Then the value and sign of the power and parameter increments are determined within one and the same period of time. The parts are brought closer together up to the moment when the ratio of the power and parameter increments reverses ints sign. Then the parts begin to be separated up to the moment when the value of said ratio reaches the preset value selected to suit the welding circuit resistance and the cross sectional area of the welded parts.

Abstract: A flash-butt resistance welding process including a flashing of parts being welded and their upsetting. The direction of speed of motion of the parts during flashing is changed by converging and diverging them. The parts being welded are converged up to the moment when the total resistance of elementary contacts arising between the flashed surfaces of the parts becomes equal to 0.4-0.5 of the short-circuit impedance of the welding machine. Then the parts are diverged up to the moment when the summary resistance of elementary contacts reaches 1.4-1.6 of the short-circuit impedance of the welding machine.

Abstract: There is proposed a control device for a flash-butt resistance welding mane, which comprises a welding transformer (1) whose primary winding is in series with a welding current pickup (7) connected to an electrohydraulic drive (30) of the moving electrode of the machine via a drive control unit (12). Said drive control unit (12) comprises two input amplifiers (14) and (15), first inputs thereof being coupled with the output of the welding current pickup (7), while second inputs of the amplifier (14) and (15) are coupled to a control voltage source (13). The output of each input amplifier (14) and (15) is connected, via transistor (21) or (22) and a voltage divider, to the input of an operational amplifier (29) whose output is connected to the input of the electrohydraulic drive (30), a welding voltage stabilizing unit being inserted into the primary circuit of the welding transformer (1), the control input of said stabilizing unit (6) being connected to the secondary winding of the welding transformer (1).

Abstract: The arrangement comprises a body constructed in the form of a grip clamp arable from the vertical axis of a workpiece, and having two jaws coupled with each other in the upper portion thereof by a clamping cylinder. The arrangement further comprises cutters for deburring, and a mechanism for pressing said cutters to the workpiece surface. The cutters are mounted in the lower portion of the jaws so that cutting edges thereof form a profile of the workpiece cross-section. The cuttes disposed on the same jaw are pivotally connected with each other. The mechanism for pressing the cutters is constructed in the form of a system of hydraulic cylinders mounted on the jaws in symmetrical relationship relative to the vertical axis of the body. Said hydraulic cylinders are provided with rods operatively connected to corresponding cutters.

Abstract: The parts to be welded together are caused to continuously approach each other and their ends are fused by an alternating current, and concurrently an oscillatory motion along the direction of approach is imparted to one of the parts, whereby additional relative movements of the parts towards and away from each other are accomplished. During the stage of a relative movement of the parts being welded together away from each other, the welding voltage is reduced to within the range of 0.7 to 0 of its working value, and during the stage of a relative movement of the parts towards each other, the voltage is restored to its initial value. Reducing the voltage is carried out in a time interval of not less than 1/8 of the period of the oscillatory motion from the beginning of the relative movement of the parts away from each other, and restoring it, in a time interval of not more than 1/8 of the period of the oscillatory motion from the beginning of the relative movement of the parts towards each other.

Abstract: A method consists in that the workpieces to be welded together are at first continuously moved towards each other with the welding current on and the ends of the workpieces are fused, the thermal state of the ends being monitored in terms of current, or of power, or of fusion time, or of length of the fused portion. After any of said variables has reached a preselected value which corresponds to the predetermined heating of the contact region, oscillatory movements are superimposed on the movement of one of the workpieces being welded towards the other and the fusion process is carried out till upsetting.

Abstract: In accordance with the disclosure, the workpieces being welded are brought together by rectilinearly oscillating at least one of them along the line of bringing them together with the amplitude in the movement of the workpiece towards the other workpiece greater than that in the movement of the same workpiece in the direction opposite to the direction towards the other workpiece, voltage is applied to said workpieces for flashing and heating them in the course of bringing them together, and then an upset force is applied to the workpieces. The hydraulic drive adapted to generate the oscillatory rectilinear motion in a continuous flash butt-welding machine includes a hydraulic cylinder with two chambers which provides for moving one of the workpieces being welded with respect to the other and comprises apparatus for feeding hydraulic fluid alternately into either of the chambers of the hydraulic cylinder of the machine, the apparatus being connected with the cylinder through two hydraulic lines.