TITANIUM ALUMINIDE ALLOY MATERIAL FOR HOT FORGING, AND METHOD FOR FORGING TITANIUM ALUMINIDE ALLOY MATERIAL

摘要

A TiAl alloy material for hot forging has a chemical composition including, by atom, aluminum of 38.0% or greater and 39.9% or less, niobium of 3.0% or greater and 5.0% or less, vanadium of 3.0% or greater and 4.0% or less, carbon of 0.05% or greater and 0.15% or less, and Ti and inevitable impurities as a residue. The TiAl alloy material for hot forging may further include boron as necessary. The TiAl alloy material for hot forging is prepared and kept at a temperature within a range of a phase equilibrium temperature of either a β-phase or a (β+α) phase in a phase diagram of a TiAl alloy so as to be forged in a non-oxidizing atmosphere. The TiAl alloy material is improved in processability during hot forging while keeping creep strength so as to enable high-speed forging.