Abstract: The present invention relates to a heat-resistant Ti alloy having excellent high-temperature strength and a process for producing the same. More particularly, the present invention relates to a heat-resistant Ti alloy having a composite structure having an equiaxed ? phase and ? grains containing an acicular ? phase inside thereof, and a process for producing the same.

Abstract: The present invention relates to a heat-resistant Ti alloy having excellent high-temperature strength and a process for producing the same. More particularly, the present invention relates to a heat-resistant Ti alloy having a composite structure having an equiaxed ? phase and ? grains containing an acicular ? phase inside thereof, and a process for producing the same.

Abstract: The present invention provides a hot-forgeable Ni-based superalloy excellent in high temperature strength, including, in terms of % by mass: C: more than 0.001% and less than 0.100%, Cr: 11.0% or more and less than 19.0%, Co: 0.5% or more and less than 22.0%, Fe: 0.5% or more and less than 10.0%, Si: less than 0.1%, Mo: more than 2.0% and less than 5.0%, W: more than 1.0% and less than 5.0%, Mo+½W: 2.5% or more and less than 5.5%, S: 0.010% or less, Nb: 0.3% or more and less than 2.0%, Al: more than 3.00% and less than 6.50%, and Ti: 0.20% or more and less than 2.49%, with the balance being Ni and unavoidable impurities, in which (Ti/Al)×10 is 0.2 or more and less than 4.0 in terms of atomic ratio, and in which Al+Ti+Nb is 8.5% or more and less than 13.0% in terms of atomic %.

Abstract: The present invention provides a hot-forgeable Ni-based superalloy excellent in high temperature strength, including, in terms of % by mass: C: more than 0.001% and less than 0.100%, Cr: 11.0% or more and less than 19.0%, Co: 0.5% or more and less than 22.0%, Fe: 0.5% or more and less than 10.0%, Si: less than 0.1%, Mo: more than 2.0% and less than 5.0%, W: more than 1.0% and less than 5.0%, Mo+½W: 2.5% or more and less than 5.5%, S: 0.010% or less, Nb: 0.3% or more and less than 2.0%, Al: more than 3.00% and less than 6.50%, and Ti: 0.20% or more and less than 2.49%, with the balance being Ni and unavoidable impurities, in which (Ti/Al)×10 is 0.2 or more and less than 4.0 in terms of atomic ratio, and in which Al+Ti+Nb is 8.5% or more and less than 13.0% in terms of atomic %.

Abstract: The present invention relates to a method of forging turbine blade, which comprises forging a plurality of turbine blades as an integrally connected body in a longitudinal direction, and then separating the integrally connected body into said respective turbine blades. According to the method of the invention, a yield of material can be improved as compared with the conventional art and the number of processes for forging work can be reduced. In addition, the turbine blades cab be forged into a favorable shape without occurring cracks. Further, it is possible to effectively reduce the cost for the die required for the forging work.

Abstract: The present invention relates to a method of forging turbine blade, which comprises forging a plurality of turbine blades as an integrally connected body in a longitudinal direction, and then separating the integrally connected body into said respective turbine blades. According to the method of the invention, a yield of material can be improved as compared with the conventional art and the number of processes for forging work can be reduced. In addition, the turbine blades cab be forged into a favorable shape without occurring cracks. Further, it is possible to effectively reduce the cost for the die required for the forging work.

Abstract: Disclosed is a method of predicting damage of dies for plastic processing of metals, typically, forging dies, to contribute to die design including choice of material, hardness and configuration of the die. The method is characterized in that the plastic flow criteria value “Dc” defined by the formula below is calculated: Dc=?eq/(YS×SRtotal), wherein ?eq is Von Misese's equivalent stress, YS is dynamic compressive yield stress, and SRtotal is softening rate, and that the damage of die is predicted with the condition that, if the value of Dc reaches 1.

Abstract: Disclosed is a method of predicting lives of dies for plastic processing of metals, typically, forging dies, to enable improved die design by predicting an important factor, low cycle fatigue life FL (shot number possible until the die lives end). The method is characterized in that the low cycle damage value “Dc” defined by the formula: Dc=?eq/(YS×softening rate), wherein, ?eq is Von Misese's equivalent stress, YS is yield stress (including both of those at tension and compression), and that the following formula is introduced: FL=C1×exp(C2×DcC3), wherein, FL is shot number until the die fracture, and C1, C2 and C3 are constants depending on the material used, so as to presume the possible shot number of the die.