To provide a method of manufacturing a shaft for a steering device, the shaft including a spline shaft part to be coupled with an input shaft, a stopper part to be coupled with an output shaft, and an intermediate shaft part that couples the spline shaft part with the stopper part. The method includes: a step of forming a hole part recessed in an axial direction from one end of a pillar-shaped material by forging; and a step of pressing the material in which the hole part has been formed into a die to perform drawing in a radial direction on a portion of the material at which the spline shaft part and the intermediate shaft part are formed, and prolonging a length along the axial direction of the hole part at the same time by forging.

To provide a method of manufacturing a shaft for a steering device, the shaft including a spline shaft part to be coupled with an input shaft, a stopper part to be coupled with an output shaft, and an intermediate shaft part that couples the spline shaft part with the stopper part. The method includes: a step of forming a hole part recessed in an axial direction from one end of a pillar-shaped material by forging; and a step of pressing the material in which the hole part has been formed into a die to perform drawing in a radial direction on a portion of the material at which the spline shaft part and the intermediate shaft part are formed, and prolonging a length along the axial direction of the hole part at the same time by forging.

The present disclosure provides a core removal punch capable of contributing to simplification of a strip mechanism. A first exemplary aspect is a core removal punch configured to form a hole in a forged product, in which a diameter of a tip part of the core removal punch is smaller than a diameter of a part of the core removal punch other than the tip part thereof, and a step part is formed between the tip part of the core removal punch and the other part thereof.

To provide a method of manufacturing a shaft for a steering device, the shaft including a spline shaft part to be coupled with an input shaft, a stopper part to be coupled with an output shaft, and an intermediate shaft part that couples the spline shaft part with the stopper part. The method includes: a step of forming a hole part recessed in an axial direction from one end of a pillar-shaped material by forging; and a step of pressing the material in which the hole part has been formed into a die to perform drawing in a radial direction on a portion of the material at which the stopper part is formed and prolonging a length along the axial direction of the hole part at the same time by forging.

A method for producing a hollow part (17; 21; 46) made of a metal material, includes preparing a blank (1; 18; 33) of the metal material of the hollow part (17; 21; 46), and at least one sacrificial mandrel (2; 19; 34, 35) made of a material which has a yield stress in the range from −30% to +20% of the yield stress of the material of the blank (1; 18; 33), preferably in the range from −15% to +10%, ideally in the range from −5% to +3%; applying a punch (10) on at least one of the ends of the blank (1; 18; 33) in order to produce the expansion of at least a portion of said blank (1; 18; 33) and to create at least one internal space (12; 20; 36, 37) inside said blank (1; 18; 33); inserting a sacrificial mandrel (2; 19; 34; 35) in said an internal space (12; 20; 37) of the blank (1; 18; 33);crimping the sacrificial mandrel (2; 19; 34, 35) in said blank (1; 18; 33);producing, by co-forging, a simultaneous deformation of said blank (1; 18; 33) and of said sacrificial mandrel (2; 19; 34, 35), with a homothetic ratio K; and performing a machining in order to remove the sacrificial mandrel (2; 19; 34, 35).

A method for piercing a titanium alloy solid billet, the method including: 1) providing a Mannesmann rotary piercer including two rollers, a feed channel, a plurality of centering devices, and a mandril including a plug; fixing the mandril using the plurality of centering devices, where the Mannesmann rotary piercer has a feeding angle of 6-18°, a cross angle of 15°, and a roll speed of 30-90 rpm; 2) heating a titanium alloy solid billet to 930-990° C.; 3) transferring the titanium alloy solid billet to the feed channel of the Mannesmann rotary piercer; and 4) aligning the titanium alloy solid billet with the plug of the mandril, and driving the titanium alloy solid billet to pass through the plug of the mandril, thereby piercing the titanium alloy solid billet and yielding a titanium alloy tube.

A method for piercing a titanium alloy solid billet, the method including: 1) providing a Mannesmann rotary piercer including two rollers, a feed channel, a plurality of centering devices, and a mandril including a plug; fixing the mandril using the plurality of centering devices, where the Mannesmann rotary piercer has a feeding angle of 6-18°, a cross angle of 15°, and a roll speed of 30-90 rpm; 2) heating a titanium alloy solid billet to 930-990° C.; 3) transferring the titanium alloy solid billet to the feed channel of the Mannesmann rotary piercer; and 4) aligning the titanium alloy solid billet with the plug of the mandril, and driving the titanium alloy solid billet to pass through the plug of the mandril, thereby piercing the titanium alloy solid billet and yielding a titanium alloy tube.

A method of making an interaxle differential unit. The method may include piercing a workpiece and then ring roll forging the workpiece to form an annular case that is a seamless ring. The annular case may be heat treated before installing an interaxle differential unit gear nest inside the annular case.

A superalloy seamless pipe and a preparation method thereof are provided. The superalloy seamless pipe comprises the following components in percentages by weight: C:0.01-0.06%, Si:0.40-1.00%, Mn:0.30-1.00%, P≤0.025%, S≤0.020%, Cr:15.00-17.00%, Ni:44.00-46.00%, Al:2.90-3.90%, Ce:0.01-0.03%, Ti:0.10-0.30%, N:0.03-0.08%, and the balance of Fe and inevitable impurities.

A method of performing pressing on a workpiece using a press machine. The pressing method includes: performing pressing on the workpiece between a lower die and an upper die by causing the upper die to approach the lower die by using the hydraulic cylinder in a state in which the workpiece is disposed between the lower die and the upper die, and performing the pressing on the workpiece between the lower die and the upper die, in a state in which a shape of each of the frame, the lower die and the upper die has a rotationally symmetric shape about the reference axis and in which the workpiece center axis coincides with the reference axis.