The development of beam steel 800L with the composition design of low carbon, microalloying of niobium, vanadium and titanium as well as controlled rolling and cooling process is carried out in the lab. Moreover, the chemical composition, heating and holding temperatures, rolling and cooling technologies are studied as well as the mechanical properties are tested and microstructure is analyzed. The results showed that the trial-produced 800L steel was with two-stage rolling after held at 1 250 ℃ and finishing temperature was set at 860 ℃, laminar cooling was carried out after rolling and finish cooling temperature was 600 ℃ so that the beam steel 800L with good mechanical properties was obtained as well as its yield strength, tensile strength and percentage elongation after fracture were 753 MPa, 845 MPa and 18.5% respectively as well as the 180° bending test was qualified.
| 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 |