チタン合金の再結晶と熱処理の基礎

抄録

From the standpoint of the actual manufacturing of all kinds of Ti alloys: α, α＋β、β alloys, basic meanings of hot working, recrystallization, and heat treatment are elucidated. The objective of this paper is to better understand the technical cores so that the results can be applied to the actual manufacturing of Ti alloys. Some of the results achieved are as follows: In α+β alloys, if true β initiation and completion recrystallization temperatures unmeasurable are assumed to be present below β transformation temperatures, non-dependence of working ratios on β recrystallized β grain sizes, when β quenched, is well explained. Why different contents of Si and Mo are added for each of high-temperature alloys such as Ti-6Al-2Sn-4Zr-2Mo-0.1Si, IMI 829, 834, and also Ti-1100, are reasonably explained in a uniform way. Irrespective of the kinds of βalloys, β recrystallization initiation and also completion temperatures are found to be equal, which signifies the same hot rolling temperatures shall be adopted without reference to β transformation temperature for each of β alloys.