Abstract: A method and apparatus for friction welding of workpieces (2, 3), which are softened and welded in a friction phase (R) with frictional contact and under frictional pressure (p) in a relative rotational movement about a process axis (8) through the effect of frictional heat. The frictional pressure (p) applied during axial advancement of one of the workpieces (3) is preferably ramped and increased during the friction phase (R).

Abstract: A pressure welding method is provided and a pressure welding machine (1) is provided with a frame (10), two welding heads (13, 14), mobile along a feed axis (41), and two adjusting units (17, 18). The adjusting units (17, 18) include feed drives (23) for the welding heads (13, 14). The two adjusting units (17, 18) are mounted so as to be axially movable (41) on the frame (10) and are interlinked with an adjusting drive (25) by means of a common adjusting element (26) and supported in a closed system of forces while receiving the pressure welding forces, thereby relieving the frame (10). The common adjusting element (26) is configured as a continuous spindle (27) having two self-locking threads (28, 29) that run in opposite directions.

Abstract: A pressure welding method is provided and a pressure welding machine (1) is provided with a frame (10), two welding heads (13, 14), mobile along a feed axis (41), and two adjusting units (17, 18). The adjusting units (17, 18) include feed drives (23) for the welding heads (13, 14). The two adjusting units (17, 18) are mounted so as to be axially movable (41) on the frame (10) and are interlinked with an adjusting drive (25) by means of a common adjusting element (26) and supported in a closed system of forces while receiving the pressure welding forces, thereby relieving the frame (10). The common adjusting element (26) is configured as a continuous spindle (27) having two self-locking threads (28, 29) that run in opposite directions.

Abstract: The invention relates to a pressure welding method and a pressure welding machine (1) which is provided with a frame (10), two welding heads (13, 14), mobile along a feed axis (41), and two adjusting units (17, 18) comprising feed drives (23) for the welding heads (13, 14). The two adjusting units (17, 18) are mounted so as to be axially movable (41) on the frame (10) and are interlinked with an adjusting drive (25) by means of a common adjusting element (26) and supported in a closed system of forces while receiving the pressure welding forces, thereby relieving the frame (10). The adjusting element (26) is configured as a continuous spindle (27) having two self-locking threads (28, 29) that run in opposite directions.

Abstract: A method and a device are provided for pressure welding, in particular for the friction welding or magnetic arc welding of workpieces (2, 3). The actual length of one or both workpieces (2, 3) and a potential length deviation (DELTA 1) from a target value is measured. If a length deviation exists, the target value of at least one parameter, in particular of the friction length, friction duration, arcing time or forge force is modified. A correction factor C, by which the length deviation (DELTA 1) is multiplied, is determined for this modification. The pressure welding device (1) includes a corresponding measuring unit (12) for determining workpiece lengths and length deviations. The controller (13) comprises an arithmetic unit (14) for setting and modifying target values, taking into account the correction factor C.

Abstract: An improved friction-welding process for effecting a joint between steel and nodular graphite-containing cast iron by using (i) a short friction-generating time so as to minimize diffusion of carbon into steel and (ii) an elevated forging pressure so as to effect a quantitative ejection of carburized melt but avoid formation of a weld laminate, is provided, as well as a nodular graphite-containing cast iron of grade 40.3 S, suitable for use in friction-welding and comprising about 280-320 graphite nodules per mm.sup.2, 280-300 ferrite grains per mm.sup.2 and a spherulite proportion of about at least 95% by weight of the graphite precipitations.