PRODUCTION OF ALPHA + BETA TITANIUM ALLOY SEAMLESS TUBE EXCELLENT IN FRACTURE TOUGHNESS

摘要

PROBLEM TO BE SOLVED: To provide a method for producing an α+β type titanium alloy seamless tube holding high strength and ductility and furthermore excellent in fracture toughness. ;SOLUTION: In the method for continuously producing a seamless tube composed of α+β type titanium alloy by a hot rolling stage of perforating, stretching, forming, drawing or the like, the final rolling stage is finished in the temp. range of the β transformation point -300°C to the β transformation point +100°C, cooling is executed at a cooling rate of that in air cooling, and furthermore, annealing is executed in the temp. range of the β transformation point to the β transformation point +100°C for 1min to 1hr. Otherwise, according to the requisitions for strength and toughness, secondary or third heat treatment is executed.;COPYRIGHT: (C)1997,JPO