α+β TYPE TITANIUM ALLOY HOT EXTRUSION SHAPE MATERIAL AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a Ti-Al-V-based α+β type titanium alloy hot extrusion shape material of an acicular structure having 0.2% bearing force of 880 MPa or more and elongation of 16% or more.;SOLUTION: There is provided an α+β type titanium alloy hot extrusion shape material containing, by mass%, Al:5.5 to 6.8%, V:3.5 to 4.5%, Fe:0.05 to 0.30%, C:0.08% or less, N:0.05% or less, O:0.20% or less, H:0.015% or less, and other element of 0.10% or less and total 0.40% or less and the balance Ti with inevitable impurities, in which a structure of a cross section vertical to a longer direction of the extrusion shape material is an acicular structure, the acicular structure has a segregation part having Al concentration of 1.06×C⁰_Al or more to content C⁰_Al in whole extrusion shape material, V concentration of 0.6×C⁰_V or less to content C⁰_V in whole extrusion shape material, aspect ratio of 10 or less, and 2 axial geometric mean diameter of a longer diameter and a shorter diameter of a circumscription rectangle of 5 to 30 μm dispersed.;SELECTED DRAWING: Figure 4;COPYRIGHT: (C)2018,JPO&INPIT