MANUFACTURE OF SEAMLESS TUBE CONSISTING OF ALPHA-TYPE OR ALPHA+BETA TYPE TITANIUM ALLOY CONTAINING SUBSTANCE FOR INHIBITING COARSENING OF STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a seamless tube which consists of an α-type or α+β type titanium alloy containing an inhibstor of the coarsening of structure, whose strength and ductility are higher in the same order in both directions of the length direction and peripheral direction and which has small anisotropy. ;SOLUTION: After a solid billet or bloom of the α-type or α+β type titanium alloy containing the substance for inhibiting the coarsening of structure is heated to the temp. range of not lower than the β-transformation temp., combined rolling of rolling for imparting a material flow in the peripheral direction of tube-making and rolling for imparting the material flow in the length direction of tube-making is executed and, in that combined rolling, the ratio RH/RL of the total sum RH of the reduction of area by the rolling for imparting the material flow in the peripheral direction to the total sum RL of the reduction of area by the rolling for imparting the material flow in the length direction is defined as the range of 0.5-2.0. In this way, the inhibition of the coarsening of structure and reduction of anisotropy are achieved.;COPYRIGHT: (C)1998,JPO