In addition to a - great gr7 titanium alloy and a + beta rods gr7 titanium alloy in recrystallization, and beta phase composition, and a number and form also changes. Determine the annealing process is also very complex. For titanium bar grade 5 metallurgy factory delivery status, the main demand with stability of plastic structure. Usually choose as the annealing temperature is alpha + beta/low beta phase transition point between 120 and 200 ℃, and cooling method is air cooling. But, for the product of final annealing, must be determined by experiments the influence of annealing process on structure and mechanical properties.
The time needed for eliminating stress annealing depends on the thickness of the workpiece, the smaller residual stress, the use of the extent of the annealing temperature and hope to get rid of stress. Considering the thickness of the workpiece, please refer to the stainless steel. The selected temperature and the desired degree of stress relief is usually determined by experiment. Heating temperature and holding time on tc4 titanium rod gr7 titanium tube and rod gr7 alloy effect of residual stress. Obviously the heating temperature is high, the required time is short.
Used for stress relief annealing cooling method usually use air cooling. The furnace cooling can also be used for big size and the shape of the parts. Rod gr7 titanium alloy stress relief annealing system. Within the scope of the recommended titanium filler rod temperature and time, should be determined by experiment according to the principle mentioned above. It should be pointed out that gr7 titanium rod welding stress relief annealing is usually considered together with the subsequent heat treatment. Stress relief annealing of cold forming parts should be to avoid contamination of fixture on the workpiece.
In full annealing process, titanium rods gr7 titanium plate and bar gr7 alloy completely annealing is the purpose of stability, good plastic or some comprehensive performance. Recrystallization is mainly occurred in the process, so also known as recrystallization annealing. In addition, alpha and beta phase composition, morphology and quantity change, too. Most of the a and a + beta rods gr7 titanium alloy are used in full annealing conditions. All type a great gr7 titanium alloy two-phase area is small, recrystallization occurs mainly in full annealing process. Usually choose as the annealing temperature is alpha + beta/low beta phase transition point between 120 and 200 ℃. High temperature will lead to unnecessary oxidation and the grain growth, low temperature and incomplete recrystallization. Cooling rate have little impact on the organization and properties of this alloy, usually use air cooling.
For the beta type rod gr7 titanium alloy, complete Titanium 6Al4V wire annealing is solid solution treatment. Annealing temperature of the metallurgy factory before shipment usually choose above a + beta/beta phase transition point between 80 and 100 ° c. In full annealing process, should according to the material processing history, actual chemical composition and the equipment used, through the experiment to determine the specific process. In order to avoid unnecessary oxidation, when choosing meet the performance requirements of process, should use the lowest temperature and the shortest time.
In recent years the nickel titanium wire beta annealing process. Great gr7 titanium alloy and a + beta rods gr7 titanium alloy in the beta phase area by air cooling after heating, and precipitation on the beta grain bulky needle (or sheets) of a. This type of structure corresponding to higher fracture toughness and creep resistance and notch sensitivity, but will reduce the plasticity index, such as the percentage reduction of area. Where appropriate, you can use it properly. In addition, for some alloy, when you need to titanium seamless tube improve in the use of temperature performance stability of working long hours, often use higher than using a second annealing temperature or using isothermal process, such as tc9 and tc6 titanium rod gr7 alloy
