• Categories:Industry information
• Time of issue:2019-07-24

(Summary description)Commonly used heat treatment methods are annealing, solution and aging treatment. Annealing is to eliminate internal stress, improve plasticity and organizational stability, and obtain better overall performance. Generally, the annealing temperature of α alloy and (α+β) alloy is selected at 120～200℃ below the (α+β)-→β phase change point; solution and aging treatment is fast cooling from high temperature region to obtain martensite α′ phase and metastable β phase, and then keep these metastable phases in the medium temperature zone to differentiate, and obtain finely dispersed second phase particles such as α phase or compounds, so as to achieve the purpose of strengthening the alloy. Generally, the quenching of (α+β) alloy is carried out at 40～100℃ below the (α+β)─→β phase change point, and the quenching of metastable β alloy is performed at 40～80℃ above the (α+β)─→β phase change point. conduct. The aging treatment temperature is generally 450 to 550 °C.

To sum up, the heat treatment process of titanium alloy can be summarized as:
(1) Stress relief annealing: The intention is to eliminate or reduce the residual stress that occurs during processing. Prevent chemical attack and cut deformation in some corrosive environments.
(2) Thorough annealing: The purpose is to obtain good toughness, improve processing performance, facilitate reprocessing and improve the stability of size and structure.
(3) Solution treatment and aging: The purpose is to improve its strength. Alpha titanium alloys and stable beta titanium alloys cannot undergo strengthening heat treatment, and only annealing is performed in production. α+β titanium alloys and metastable β titanium alloys containing a few α phases can be further strengthened by solution treatment and aging.
In addition, in order to meet the special requirements of the workpiece, the industry also uses two-layer annealing, isothermal annealing, beta heat treatment, deformation heat treatment and other metal heat treatment processes.