The Application Prospect of Titanium Alloy Helical Compression Spring in Rail Transportation Industry
The helical compression spring is a key component in the suspension system of rail transit vehicles. When the vehicle is running on the track, that will be accompanied by a complex vibration phenomenon; when the rail on the wheel to have a counter-impact force, the coil spring is deformed to absorb the kinetic energy of the rail impact, at the same time is converted to the potential energy of the spring, thereby easing the rail impact on the body impact.
The vehicle using a helical compression spring, can improve the comfort and stability of the vehicle running, to ensure passenger comfortable and safety, to guarantee the integrity of non-destructive goods, while the helical compression spring to have a high fatigue life and high reliability of the two characteristics. The main factors affecting the fatigue life and reliability of the spring, include the spring structure, surface quality, stress, the tip of the end of the seam shot blasting situation.
Compared with steel springs, titanium alloy spring has a light weight, high strength, good damping, wide operating temperature range(-50 ~ 300℃), low stress, corrosion resistance and other six advantages. Among them, the light weight and corrosion-resistant two advantages, you can reduce the weight of the vehicle suspension device to improve the speed of the train, to better extend the life of the vehicle parts and rails, reducing the number of vehicle maintenance. The following table shows the performance of helical compression spring steel material and titanium alloy material comparison.
| Material | Tensile Strength(MPa) | Yiled Strength(MPa) | Enlongation(%) | Reduction of Area(%) | Impact Work at Room Temperature(J) |
| 51CrV4 | ≥ 1300 | ≥ 1200 | ≥ 6 | ≥ 30 | ≥ 8 |
| TB6 | ≥ 1250 | ≥ 1200 | ≥ 8 | ≥ 25 | ≥ 10 |
| TB9 | ≥ 1400 | ≥ 1200 | ≥ 8 | ≥ 30 | ≥ 10 |
Comparison of performance of spring steel 51CrV4 and titanium alloy TB6 and TB9.
Below is a series of spring (inner spring and outer spring) for CRH3 high-speed train with titanium TB6 trial. Manager on the calculation and testing, the titanium spring a series of indicators which are in range with the requirements of the High Speed Train. Some of the helical compression springs used in the subway and Light Rail have been designed with titanium Springs, but have not yet been tested.
