α+&bgr; TYPE TITANIUM ALLOY PLATE FOR WELDING PIPE EXCELLENT IN PIPE-FORMING ABILITY, METHOD FOR PRODUCING THE SAME, AND α+&bgr; TYPE TITANIUM ALLOY WELDING PIPE PRODUCT EXCELLENT IN STRENGTH AND INTENSITY IN LONGITUDINAL DIRECTION OF THE PIPE

摘要

PROBLEM TO BE SOLVED: To provide: an α+β type titanium alloy plate for a welding pipe, with enhanced pipe-forming ability; a method for producing the same; and an α+β type titanium alloy welding pipe product with enhanced strength and intensity in a longitudinal direction of the pipe.

SOLUTION: The α+β type titanium alloy plate is used in a welding pipe in which a rolling direction is a peripheral direction, has a predetermined composition, and is characterized in that: a collected structure in a plate face direction has first crystal particles oriented in an area in which an angle θ formed by a c axis and a normal line direction in a (0002) pole figure of an α phase having a hexagonal crystal structure is 0 to 30° and second crystal particles oriented in an area in which the above angle θis 80 to 100° and an angle Φ formed by a projecting line to the plate face of the c axis and a plate width direction in the (0002) pole figure of the α phase is -10 to 10°; and a ratio ((the second crystal particles)/(the first crystal particles)) of the strongest values of X-ray relative strengths from the bottom face of the α phase in the first crystal particles and the second crystal particles is 5.0 or more.

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