The effects of microstructure of high-strength anti-seismic fire-resistant H beam for building structure on its strength, toughness and high temperature strength are studied with such analysis means as TEM (transmission electron microscope), metallographic microscope and EBSD (electron back-scattered diffraction). The results showed that the controlled rolling and controlled cooling were not needed under the premise of reasonable chemical composition design, two-phase structure of air cooling bainite and ferrite for test steel after hot rolling was obtained. It is found by observing the microstructure after holding at 600 ℃ for 3 hours that there is nano-level interphase precipitates in ferrite and their line spacing is about 24~34 nm. For the hot rolled high-strength anti-seismic fire-resistant H beam for building structure, its yield strength≥500 MPa, elongation≥22%, yield ratio≤0.85, impact energy at -20 ℃≥34 J and yield strength after holding at 600 ℃ for 3 hours≥310 MPa.
| 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 |