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In order to improve product quality and strengthen quality monitoring of high speed rail, the chemical composition of U71Mn rail is optimized, Mn content in steel is reduced and rolling process is controlled as well as the trial productions are carried out for such whole series of sections as 60 N, 60 kg/m, 50 kg/m, QU120, QU100 and QU80 of U71Mn. The results showed that the tensile strength was reduced by 7.2 MPa and mean value reached 950 MPa, tread hardness (HB) was reduced by 2.8 and mean value reached 269.2 as well as elongation is basically unchanged by comparing the performances of U71Mn rail with those before optimization. Moreover, the ideal perlite structure is obtained, performances of rail could all meet the standard requirements and is with enough margin so that the effects are better.
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| 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 |
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