In this article, it is introduced a series of high temperature tempering tests for 75 kg/m on-line as-heat-treated bainite rails in the laboratory as well as compared and analyzed the conventional mechanical properties, fracture toughness at-20 ℃, spreading rate of fatigue crack, residual stress and microstructure of rails with different tempering processes. The test results show that the strength, hardness and residual stress of on-line as-heat-treated rails decrease linearly; such toughness indexes as fracture toughness at-20 ℃ and impact energy firstly decrease and then increase with the tempering temperature increases as well as the performance indexes of fracture toughness and spreading rate of fatigue crack are better than those at low temperature tempering state. The on-line as-heat-treated with high temperature tempering is with higher fracture toughness and lower spreading rate of fatigue crack so that the characteristics of high toughness and resistance to generation and spread of crack for bainite rails could be further exerted.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |