Methods of refining the grain size of a titanium alloy workpiece include beta annealing the workpiece, cooling the beta annealed workpiece to a temperature below the beta transus temperature of the titanium alloy, and high strain rate multi-axis forging the workpiece. High strain rate multi-axis forging is employed until a total strain of at least 1 is achieved in the titanium alloy workpiece, or until a total strain of at least 1 and up to 3.5 is achieved in the titanium alloy workpiece. The titanium alloy of the workpiece may comprise at least one of grain pinning alloying additions and beta stabilizing content effective to decrease alpha phase precipitation and growth kinetics.

A forging die device is configured in such a manner that die heating heater plates 11, 21 are disposed respectively between a die 1 which is held at the outer periphery by die holders 12, 22, and die holding means 14a, 24a composed of heat insulating plates 13, 23 and die plates 14, 24, and the die holders, the die holding means and the die plates are integrated together. After the preheated die 1 is placed on the heated die holding means, the die 1 is heated by heating means, and forming surfaces 10a, 20a of the die are heated to a required temperature immediately before forging.

A forging die device is configured in such a manner that die heating heater plates 11, 21 are disposed respectively between a die 1 which is held at the outer periphery by die holders 12, 22, and die holding means 14a, 24a composed of heat insulating plates 13, 23 and die plates 14, 24, and the die holders, the die holding means and the die plates are integrated together. After the preheated die 1 is placed on the heated die holding means, the die 1 is heated by heating means, and forming surfaces 10a, 20a of the die are heated to a required temperature immediately before forging.

The invention relates to a die heating system that is developed for preheating and continuous heating of forging dies (12) internally. The dies (12) are provided with channels (13) in which electrical heating cartridges (15) are placed with built-in thermocouples (16) monitored by a PID thermostat. The channels are located optimally in a zone (C) close to the die cavity for efficient heating but outside the zones of high forging load (D) or of rework requirement (B) or of high forging load after rework (A).

The invention relates to a die heating system that is developed for preheating and continuous heating of forging dies (12) internally. The dies (12) are provided with channels (13) in which electrical heating cartridges (15) are placed with built-in thermocouples (16) monitored by a PID thermostat. The channels are located optimally in a zone (C) close to the die cavity for efficient heating but outside the zones of high forging load (D) or of rework requirement (B) or of high forging load after rework (A).

A method and a plant for manufacturing fasteners, in particular screws, along an automated production line; the method comprising the following steps: feeding the raw material made of titanium; heating the raw material to a predefined temperature; cutting one or more pieces of a predefined length, in succession, from the heated raw material; deforming plastically each piece by means of one or more finishing stations, so as to obtain a fastener; heating, during the deforming step, the material that passes through each workstation to a predefined temperature; wherein the material manipulated along the production line during the feeding, heating, and deforming steps is automatically transported along the production line.

A method and a plant for manufacturing fasteners, in particular screws, along an automated production line; the method comprising the following steps: feeding the raw material made of titanium; heating the raw material to a predefined temperature; cutting one or more pieces of a predefined length, in succession, from the heated raw material; deforming plastically each piece by means of one or more finishing stations, so as to obtain a fastener; heating, during the deforming step, the material that passes through each workstation to a predefined temperature; wherein the material manipulated along the production line during the feeding, heating, and deforming steps is automatically transported along the production line.

A constant velocity drive shaft manufacturing method capable of manufacturing a constant velocity drive shaft among drive shafts with high efficiency and with stable and high accuracy. A method for manufacturing a constant velocity drive shaft by full enclosed die cold forging including a metal mold pair including an upper metal mold and a lower metal mold includes an annealing step of partially annealing a molding material at positions where a first large-diameter part and a second large-diameter part included in the constant velocity drive shaft are respectively molded, a cooling step of cooling the molding material partially annealed in the first step, and a molding step of molding in one step a first large-diameter part, a second large-diameter part, and a third large-diameter part in the molding material cooled in the second step by pressing with the metal mold pair and pressing from both directions of the molding material.

A constant velocity drive shaft manufacturing method capable of manufacturing a constant velocity drive shaft among drive shafts with high efficiency and with stable and high accuracy. A method for manufacturing a constant velocity drive shaft by full enclosed die cold forging including a metal mold pair including an upper metal mold and a lower metal mold includes an annealing step of partially annealing a molding material at positions where a first large-diameter part and a second large-diameter part included in the constant velocity drive shaft are respectively molded, a cooling step of cooling the molding material partially annealed in the first step, and a molding step of molding in one step a first large-diameter part, a second large-diameter part, and a third large-diameter part in the molding material cooled in the second step by pressing with the metal mold pair and pressing from both directions of the molding material.

A forging and pressing production systems enables at least one material to be formed by hot melt and forging and pressing by itself without human operation, thereby completing the mass production of the material. Operating factors such as the pressure, temperature and mold required for formation are taken into account, and the identification requirements for the material are reduced, thereby realizing large-scale production.