A method for manufacturing a blisk includes an intermediate product molding step of molding a blisk intermediate product including a circular disk-corresponding part, a plurality of rotor blade-corresponding parts, and bridges each connecting a front edge of one of each pair of the rotor blade-corresponding parts adjacent to each other and a rear edge of the other one of the rotor blade-corresponding parts. The method for manufacturing the blisk further includes a disk finishing step of cutting the disk-corresponding part so as to finish the disk-corresponding part into the disk in a product form, and a rotor blade finishing step of cutting each bridge so as to finish the respective rotor blade-corresponding parts into the respective rotor blades in a product form.

An annular reference surface is formed around a through-hole of an eye portion. A distal-end-side curved portion is formed at a first corner portion, on an outer side of the annular reference surface. The thickness of the distal-end-side curved portion is reduced in a range of a length from the first flat surface toward the distal end surface. A hole-side curved portion whose thickness is reduced toward an inner surface of the through-hole is formed at a second corner portion, on an inner side of the annular reference surface. The length of the hole-side curved portion is less than the length of the distal-end-side curved portion. The hole-side curved portion is curved with a greater curvature than that of the distal-end-side curved portion.

A method to improve the collapse resistance of metallic tubular products is disclosed. The method comprises identifying the types of stress that can be applied in order to change the residual stress profile of metallic tubular products, such as those that have completed a straightening process, and results in a residual stress profile that improves collapse resistance. The metallic tubular product is subjected to radial compression processing to control the residual stress profile and to enhance collapse resistance. The radial compression process may be used after the tubular product has been subjected to a straightening process.

A forging die apparatus includes: an upper mold holder installed to be movable in a vertical direction, an upper mold detachably installed in the upper mold holder, a lower mold holder installed to be movable in the vertical direction, a lower mold detachably installed in the lower mold holder, and a stopper unit detachably installed in one of the upper mold holder and the lower mold holder to selectively restrain the vertical movement of the one of the upper mold holder and the lower mold holder in which the stopper unit is installed.

A forged crankshaft production method includes a first preforming step, a second preforming step, and a final preforming step. The first pair of dies includes web processing parts to come into contact with portions to be formed into arms and portions to be formed into weights integrated with the arms. Each of the web processing parts includes an arm processing part and a weight processing part. The arm processing part and the weight processing part form a recessed portion, and the width of the open side of the weight processing part becomes greater with increasing distance from the bottom of the recessed portion. Accordingly, in the blank, volume can be distributed between a portion to be formed into an arm and a portion to be formed into a weight integrated with the arm, and the material yield rate can be improved.

The present disclosure relates to a steel forging process, in particular a hot steel forging process in horizontal press of a metal tube, preferably a cylindrical steel tube.

A hollow forging process for main shaft of large wind turbine generator, wherein, comprising the following steps as: the first step of cutting off the dead head and the bottom of an ingot; the second step of upsetting and punching a hole; the third step of drawing-out; and the fourth step of local upsetting, drawing-out and shaping-up. In the fourth step, the forged piece is shaped up by local upsetting and drawing-out through a turnplate. The hollow forging process for main shaft created by the invention can save the costs for enterprise to purchase large equipment and makes it possible to forge the main shaft of large wind turbine generator with a free forging oil press with a smaller size.

In an embodiment a method for reading a marking includes providing the marking on a substrate, the marking being formed with at least one marking material, providing at least one opaque covering layer covering the marking, briefly irradiating the at least one covering layer with electromagnetic radiation to which the at least one covering layer is impermeable; and contactless reading the marking by thermal imaging.

A forging apparatus carries out a method of manufacturing a gear having external teeth on an outer circumferential wall surface thereof and internal teeth on an inner circumferential wall surface thereof. First, an internal tooth forming die is inserted through a through hole defined in a workpiece. Next, a pressing die is caused to abut against the workpiece, and an external tooth machining die finishes the external teeth while preventing a support die from being lowered under action of damping mechanisms. Thereafter, a pressing die presses the workpiece to apply a load in excess of a preset load for the damping mechanisms. The support die is then lowered to lower the workpiece along the internal tooth forming die. At this time, the internal teeth are formed on the inner circumferential wall surface of the workpiece.

A method and apparatus for simultaneously producing a first piston part and a second piston part via a forging device may include an upper die, at least one intermediate die, and a lower die. A first billet may be placed between the upper die and the intermediate die, and a second billet may be placed between the intermediate die and the lower die. The upper die and the lower die may be configured to be moved toward each other, whereby the first piston part is forged from the first billet and the second piston part is forged at the same time from the second billet. The upper die and the lower die may then be configured to be moved apart, and the piston parts may be removed.