| Autor: |
Tran, Lily, Cong Qiu, Mutton, Peter, Cookson, John, Wenyi Yan |
| Předmět: |
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| Zdroj: |
EA National Conference Publications; 2023, p517-525, 9p |
| Abstrakt: |
Thermal or thermo-mechanical loading is one of the major causes of steel wheel surface damage in heavy haul railway operations. This damage mode originates from the combination of high contact stresses from normal wheel-rail contact as well as substantial thermal loading by using tread brakes. Continuous usage of tread brakes, such as during prolonged periods of braking, can further exacerbate thermal loads. This can lead to severe plastic deformation and microstructural deterioration, which can substantially reduce the operational life of the wheels. Under such circumstance, the hot strength of the wheel material and the microstructural stability of the wheel metallurgy at typical temperature ranges during normal revenue service influence the resistance of wheel material to thermo-mechanical damage. A study was completed to better understand wheel material behaviour during service, where wheel steel materials are exposed to high loads and elevated temperatures. Hot compression testing was used to simulate this process, and it was found that with increasing temperatures, the yield stress was relatively stable until 450°C, above which it decreased linearly. A microstructural comparison using optical microscopy found little change between testing conditions. Further comparisons using scanning electron microscopy identified an increasing extent of microstructure decomposition with increasing temperature. The study helps to define the temperature range where the wheel materials become sensitive and prone to thermal softening, which can be used to guide the optimisation of braking strategies and reduce the propensity of wheel thermal-mechanical damage. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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