Full
Outline
The bake hardening steel is with good deep drawing properties and dent resistance, so it is usually used for stamping exterior covering parts of automobile. The cold rolled ultra-low carbon bake hardening steel HC220B is successfully developed by adding a small quantity of Ti into ultra-low carbon steel based on customer requirements as well as with the production mode of continuous annealing based on existing production equipment of such production lines as steel making, hot rolling and cold rolling in Rare Earth Steel Plate Co. of Baotou Steel. The mechanical properties of steel strip could meet the standard requirements so that the yield strength is 220~270 MPa, tensile strength is 320~400 MPa, percentage elongation after fracture≥32.0%, n -value≥0.16, r -value≥1.5, BH2 value≥30 MPa, metallographic structure is equiaxed ferrite and grain size is grade 8.5 for finished product. When the content of solid solution free carbon in steel is within the range of 3~21 ppm, cold rolled bake hardening steel HC220B is with suitable bake hardening values. The mechanical properties of steel strip could still meet the standard requirements after it is stored at room temperature for over 3 months, so it is with good aging. When the content of free carbon reaches 58 ppm, steel strip ages rapidly and its yield strength is increased by approximately 40 MPa after it is stored at room temperature for 1 month, which is unfavorable to stable use of customers.
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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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