The invention relates to a corrosion resistant titanium-niobium alloy method for preparing pipes, which is particularly composed of the following steps:
(1) Ingot preparation: Titanium sponge and pure niobium are used to mix and press the electrode block according to the ratio of claim 1, and the electrode block is combined to prepare the primary electrode, and then the ingot is prepared by vacuum consumable arc melting twice;
(2) Forging preparation of rod billet: The surface of the ingot was coated before the ingot was heated. The forging temperature was 900 ~ 1100℃, the holding temperature was 2 ~ 5 hours, the forging ratio was 2 ~ 5, the final forging temperature was ≥750℃, the bar forging temperature was 800 ~ 1000℃, the holding temperature was 1 ~ 3 hours, the forging ratio was 2 ~ 5, the final forging temperature was ≥700℃.
(3) Preparation of tube billet: The tube billet is prepared by extrusion method or skew-rolling perforation method. Before extrusion, the bar billet is skin drilled and the surface coating is processed. The extrusion temperature is 700 ~ 850℃, and the heat preservation is 1 ~ 3 hours.
(4) Surface treatment: pickling and washing should be carried out on the hot-processed tube billet, or alkali washing, pickling and washing to remove the surface coating or surface oxide, and then surface peeling, the inner surface is treated by boring, and the boring amount is 0.2 ~ 1.5mm;
(5) Cold rolling: Before cold rolling, vacuum heat treatment is used or rolled directly after surface treatment, two-roll cold rolling and at least two times of diameter and wall reduction rolling, the last time is multi-roll fine rolling out of finished products, the inside and outside surfaces of the billet or semi-finished pipe are lubricated with liquid lubricant, the rolling speed is 10 ~ 80 times/min, and the deformation of each time is 20% ~ 70%. The total processing rate is 30% ~ 70%;
(6) Degreasing treatment: For the pipes undergoing vacuum heat treatment after cold rolling, degreasing treatment needs to be carried out, first ultrasonic cleaning degreasing or degreasing agent cleaning, and then pickling, washing and drying treatment;
(7) Intermediate and finished heat treatment: Intermediate softening and finished heat treatment are all vacuum annealing heat treatment, annealing temperature is 600 ~ 800℃, heat preservation 1 ~ 2 hours, vacuum degree is not less than 1×10-1Pa, after the intermediate annealing of the product return step (5) continue rolling, after the finished product annealing directly into the finished product, or after pickling and washing to become the finished product;
