Commonly used methods of annealing heat treatment

Commonly used methods of annealing heat treatment, solution and aging treatment. Annealing is to eliminate stress, improve plasticity and organizational stability, in order to obtain a better overall performance. Typically α alloys and (α + β) alloy annealing temperature selected in the (α + β) ─ → β phase transition point below 120 ~ 200 ℃; solution and aging treatment is rapid cooling from high temperature zone to obtain martensite α 'phase and the metastable β phase, and then incubated in the temperature region of these metastable phase decomposition to obtain compound α phase or the dispersed second phase particles, achieve the purpose of strengthening the alloy. Typically (α + β) quenching the alloy in (α + β) ─ → β phase transition point of 40 ~ 100 ℃ were metastable β quenched alloy in the (α + β) ─ → β phase transition point above 40 ~ 80 ℃ get on. Aging treatment temperature is generally 450 ~ 550 ℃.
Summary, titanium heat exchanger alloy heat treatment process can be summarized as follows:
(1) stress relief annealing: The aim is to eliminate or reduce the residual stresses generated during machining. Prevent chemical erosion and reduce distortion in some corrosive environments.
(2) complete annealing: The purpose is to obtain good toughness, improve the processing performance, is conducive to further processing and to improve the stability of the size and organization.
(3) solution treatment and aging: The purpose is to increase its strength, α β titanium alloy and stability can not be strengthened heat treatment is carried out only in the production of annealing. α + β titanium and titanium alloys metastable β phase can contain small amounts of α by solution treatment and aging of the alloy further strengthened.
In addition, in order to meet the special requirements of the workpiece, the industry also uses double annealing, isothermal annealing, β heat treatment, deformation and heat treatment of metal heat treatment