The strength of 440 MPa grade phosphorous high-strength IF steel independently developed by Baotou Steel is improved by adding such alloying elements as Si, Mn and P based on ultra low carbon steel. The control requirements of its composition and production process are strict as well as production is very difficult. In the paper, the influences of chemical elements on stamping performance of 440 MPa grade high-strength IF steel are mainly studied. The microstructure of steel strip, inclusion morphology and precipitation behavior of the second phase particles are analyzed with metalloscope and scanning electron microscope. The mechanisms of action of hot rolling processes such as finishing and coiling temperatures, continuous annealing process of cold rolling on microstructure and mechanical properties are explained. The mechanical performances of tested steel strip are stable and could meet the relative technical requirements through formulating reasonable process route and strict control.
| 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 |