Titanium alloy rolling technology is an important metalworking process that involves forming titanium alloy materials into desired shapes and sizes through rolling.
Key Process Points
The titanium rolling process is a critical step in titanium alloy production, directly affecting the material's microstructure and macroscopic properties. The following are some key points about titanium alloy rolling:
1. Rolling Temperature Control:
Titanium alloys have a narrow rolling temperature window and poor thermal conductivity, making slab temperature control crucial. Excessively high starting rolling temperatures or excessive rolling deformation can cause a sharp rise in temperature in the center of the workpiece, resulting in poor plasticity and uneven rolling.
2. Multi-Pass Rolling:
The rolling of titanium alloy sheets typically requires multiple hot rolling passes, which are suitable for controlling the material's microstructure and properties. Annealing may be required between passes to restore the material's plasticity.
The material thickness is gradually reduced through multiple rolling passes.
3. Reduction Distribution:
During the rolling process, the distribution of reduction has a significant impact on the material's anisotropy. For example, when the reduction ratios for the horizontal and vertical rolling passes are distributed at a 1:1 ratio, material anisotropy is essentially eliminated.
4. Rolling Speed:
Rolling speed affects the temperature distribution of the slab, which in turn affects rolling quality and production efficiency. During the initial rolling phase, a low speed is generally used to prevent accidents caused by biting. As the thickness of the workpiece decreases, the rolling speed can be increased, but generally within a certain range.
5. Rolling Equipment:
Using advanced rolling equipment, such as fast transverse reversing mills, tandem mills, precision mills, and modular mills, can improve rolling efficiency and product quality.
6. Automated Control System
Developing a fully automated control system for the entire process enables automated production with temperature and rolling control, improving the automation and intelligence of the production process.
7. New Rolling Process
Using a three-roll Y-type mill instead of a traditional two-roll mill enables single-line torsion-free, low-tension rolling and increases rolling speed.
8. Determining the Rolling Window:
The rolling temperature window for hot-rolled titanium alloys is determined through experimental and simulation analysis, providing a basis for developing hot-rolling process specifications.
9. Billet Preparation:
Pure titanium and low-alloyed alloy grades can be supplied in the form of die forging, billet, or slab. High-alloyed alloy grades require open forging.
10. Rolling Procedure Development:
The development of rolling procedures includes billet design, reduction schedule, speed schedule, and temperature schedule, taking into account material properties, equipment capabilities, and production efficiency.
Technical Features
1. Hot Rolling:
Hot rolling is a rolling process performed above the recrystallization temperature of the metal material. It significantly reduces the material's deformation resistance and improves rolling efficiency.
It is suitable for the production of large-sized titanium alloy plates and bars.
2. Cold Rolling:
Cold rolling is a rolling process performed at room temperature. It can improve the material's surface quality and dimensional accuracy, but it requires higher plasticity.
It is typically used to produce high-precision thin plates and strips.
3. Reversible Rolling:
Reversible rolling involves passing the workpiece through the rollers multiple times during the rolling process, reversing its direction after each pass to improve the material's anisotropy.
4. Near-Isotropic Rolling
This innovative rolling concept achieves near-isothermal rolling of titanium alloys by controlling the deformation amount, deformation speed, and rolling cycle, improving rolling efficiency and material properties.
5. Extraordinary Passes and Flexible Rolling
This allows for the use of different rolling pass profiles and rolling schedules to accommodate varying material properties and production requirements.
6. "One-hot Productivity" New Efficient Rolling Model
Through innovative rolling concepts and processes, efficient production of aviation-grade titanium alloys is achieved, reducing the weight of small-gauge wire coils.
7. Large-gauge BDM850 Rapid Traverse Reversing Mill
This equipment is specifically designed for rolling large-section titanium alloys, enabling minimal interpass intervals and high-efficiency rolling.
8. Walking Mill, Spiral Mill, Y-Type Mill, Planetary Mill
Each rolling equipment has its own unique characteristics and is suitable for producing bars of varying specifications.
The development of titanium alloy rolling technology continues to drive advancements in material processing. By improving rolling processes and equipment, the comprehensive performance of titanium alloys can be enhanced to meet the demands of the high-end market.
