Abstract: A low-alloyed steel, comprising about 0.3 to about 0.50 wt. % carbon, about 2.0 to about 5.0 wt. % silicon, and a remainder of iron, optionally containing low amounts of molybdenum, titanium and/or boron, with up to about 0.5 wt. % impurities. The low-alloyed steel is useful for making structural components having a tensile strength of greater than about 1000 to about 2000 MPa, a yield strength of greater than about 700 to approximately 950 MPa; a break elongation of greater than about 17% and a scaling resistance of greater than about 650° C.

Abstract: A low-alloyed steel, comprising about 0.3 to about 0.50 wt. % carbon, about 2.0 to about 5.0 wt. % silicon, and a remainder of iron, optionally containing low amounts of molybdenum, titanium and/or boron, with up to about 0.5 wt. % impurities. The low-alloyed steel is useful for making structural components having a tensile strength of greater than about 1000 to about 2000 MPa, a yield strength of greater than about 700 to approximately 950 MPa; a break elongation of greater than about 17% and a scaling resistance of greater than about 650° C.

Abstract: A process for near-net-shape manufacturing of a formed metallic work piece with armoring, with the armoring having different properties than the basic work piece material, including the steps of providing an armoring blank; providing a basic work piece blank; arranging the armoring blank on the basic work piece blank; welding together a surface section of the work piece blank and the armoring blank, thereby creating a blank with an armored surface section; and forming the resulting blank with an armored surface section, thus producing a near-net-shape work piece contour by means of a process which is selected from the group comprising: forging, upsetting, electro upsetting, and extrusion, at a temperature in one of a cold, half-warm and warm temperature range, thereby producing a near-net-shaped formed armored work piece.

Abstract: A process for producing a rotationally symmetric hollow part, especially a shaft, including: providing a bar-shaped solid material involving the steps of heating the solid material substantially to forging temperature; cross wedge rolling of the solid material so as to cause weakening in the core zone of the solid material; and inserting at least one rotating mandrel, driven at a predetermined velocity, substantially along the central axis of the cross-wedge-rolled solid material, thus creating a through-hole and to a rotationally symmetric hollow part, especially a shaft.

Abstract: A method for producing a rotationally symmetrical hollow metal part, particularly a shaft. According to the method, bar-shaped ductile solid material is provided, the solid material is heated from about 300° C. below the forging temperature to the forging temperature, the solid material is transversally spline-rolled until weakenings are created in the core zone (3) of the solid material and the sold material is torn open. Two mandrels (5,6) are forcibly introduced into the center of the bar-shaped solid material during the rolling process, and then one mandrel is retracted while the other mandrel continues advancing so as to produce a tubular part. A transversally spline-rolled rotationally symmetrical hollow part, especially a shaft, which is produced according to noted method can be embodied as a transmission shaft, camshaft, drive shaft, output shaft, starter shaft, hollow shaft, or can be a preform for molded parts and the like.

Abstract: A device and method are provided for forging sleeve-shaped parts such as pistons. The device includes a form with: an upper form mandrel (C); an outer form ring (A); a lower form mandrel (B); an ejector device with an upper ejector (G) for ejection through the upper form mandrel (C); a lower ejector (H) for ejection through the lower form mandrel (B). Optional support devices for the form include a lower reinforcement ring (D) for the lower region of the outer form ring (A), a form mandrel housing (F) for the upper region of the outer form ring (A), and a clamping base (E) to support the lower form mandrel (B), by means of which the lower ejector (H) may be operated. The device and method advantageously facilitates the manufacture of pistons having a long skirt length and a minimal wall thickness.

Abstract: A method of friction welding a head part to a skirt part of a piston having a hollow cooling duct in which the internal connection surface of the first part to be welded is reciprocally arranged with an internal connection surface of the second part to be friction welded, so that they form a unsymmetrical contact area, so that the resulting weld of the first and the second parts produces a weld bead that is located predominantly outside of the hollow cooling duct. The unsymmetrical contact area can be formed by chamfered, angled edge surfaces that produce, for example, a wedge-shaped space, or partially matched, inter-fitting surfaces that remain out of contact and produce a gap at sides facing the hollow space.

Abstract: A method of friction welding a head part to a skirt part of a piston having a hollow cooling duct in which the internal connection surface of the first part to be welded is reciprocally arranged with an internal connection surface of the second part to be friction welded, so that they form a unsymmetrical contact area, so that the resulting weld of the first and the second parts produces a weld bead that is located predominantly outside of the hollow cooling duct. The unsymmetrical contact area can be formed by chamfered, angled edge surfaces that produce, for example, a wedge-shaped space, or partially matched, inter-fitting surfaces that remain out of contact and produce a gap at sides facing the hollow space.

Abstract: A method for producing a rotationally symmetrical hollow metal part, particularly a shaft. According to the method, bar-shaped ductile solid matrial is provided, the solid material is heated from about 300° C. below the forging temperature to the forging temperature, the solid material is transversally spline-rolled until weakenings are created in the core zone (3) of the solid material and the sold material is torn open. Two mandrels (5,6) are forcibly introduced into the center of the bar-shaped solid material during the rolling process, and then one mandrel is retracted while the other mandrel continues advancing so as to produce a tubular part. A transversally spline-rolled rotationally symmetrical hollow part, especially a shaft, which is produced accoridng to noted method can be embodied as a transmission shaft, camshaft, drive shaft, output shaft, starter shaft, hollow shaft, or can bea preform for molded parts and the like.

Abstract: A device and method are provided for forging sleeve-shaped parts such as pistons. The device includes a form with: an upper form mandrel (C); an outer form ring (A); a lower form mandrel (B); an ejector device with an upper ejector (G) for ejection through the upper form mandrel (C); a lower ejector (H) for ejection through the lower form mandrel (B). Optional support devices for the form include a lower reinforcement ring (D) for the lower region of the outer form ring (A), a form mandrel housing (F) for the upper region of the outer form ring (A), and a clamping base (E) to support the lower form mandrel (B), by means of which the lower ejector (H) may be operated. The device and method advantageously facilitates the manufacture of pistons having a long skirt length and a minimal wall thickness.

Abstract: A method of friction welding a first part to a second part of a component having a hollow space in which the internal connection surface of the first part to be welded is reciprocally arranged with an internal connection surface of the second part to be friction welded, so that they form a unsymmetrical contact area, so that the resulting weld of the first and the second parts produces a weld bead that is located predominantly outside of the hollow space. The unsymmetrical contact area can be formed by a chamfer, angled edge surfaces that produce, for example, a wedge-shaped space, or partially matched, inter-fitting surfaces that remain out of contact at sides facing the hollow space.

Abstract: A hollow shaft with torque-transmitting structural elements such as toothed gears, cams, disc cams, etc., is optionally provided with secondary shaping elements, such as bearing points, stop faces, hexagonal or ring contours, etc. The new shaft is formed from a starting pipe with a substantially uniform wall thickness, which is widened for the positive (form locking) and non-positive (force-fit) connection to the structural elements and for shaping the secondary shaping elements by internal pressure. The maximum widening of the pipe is under the structural elements or on the secondary shaping elements. The new hollow shaft is characterized in that the wall thickness of pipe (12) under the structural elements (14,18) and optionally secondary shaping elements (16,20) is partly enlarged in the axial direction by material flow compared with the wall thickness of the starting pipe.

Abstract: A hollow shaft is provided with torque transmitting structural elements, such as gear wheels, cams, disk cams, etc. At least one structural element has a noncircular opening for mounting on a discharge pipe (12) with a substantially identical wall thickness and with at least one support body (20) between the pipe (12) and each structural element (14) with noncircular opening. The discharge pipe (12) is so widened by internal pressure for frictional connection to the structural elements (14) that cover a portion thereof that the circumference of the pipe (12) engages on the inner wall of the structural elements (14) and another portion of the pipe circumference engages on the outer wall of the support body (20). Each support body (20) is constructed as a separate component from the structural elements.

Abstract: A process for the production of flanges or collars on hollow parts by lateral extrusion in which the hollow part is supported internally during lateral extrusion, and the support is provided by an elastic and/or plastic medium inserted in the hollow space.