The common heat treatment methods of titanium tubes are annealing, solid solution and aging treatment. Annealing is to eliminate internal stress, improve plasticity and organizational stability, and obtain better comprehensive properties. Usually, the annealing temperature of α alloy and (α+β) alloy is selected at 120-200℃ below the (α+β)-→β phase transformation point; solution and aging treatment is fast cooling from high temperature region to obtain martensite α′ phase and metastable. Then, these metastable phases are decomposed by heat preservation in the medium temperature zone, and finely dispersed second phase particles such as α phase or compounds are obtained to achieve the purpose of strengthening the alloy.

The heat treatment process of titanium tube can be summarized as:

(1) Solution treatment and aging: the purpose is to improve its strength. The α titanium tube and the stable β titanium tube cannot be subjected to strengthening heat treatment, and only annealing is carried out in production. α+β titanium tubes and metastable beta titanium tubes containing a small amount of α phase can be further strengthened by solution treatment and aging.

(2) Complete annealing: the purpose is to obtain good toughness, improve processability, facilitate reprocessing and improve the stability of size and structure.

(3) Stress relief annealing: the purpose is to eliminate or reduce the residual stress generated during processing and prevent chemical attack and reduce deformation in some corrosive environments.

In addition, in order to meet the special requirements of the workpiece, industrial titanium tubes also use metal heat treatment technics such as double annealing, isothermal annealing, beta heat treatment, and deformation heat treatment.