In this research, DC56D+ZM steel plate and DC56D+Z steel plate with coating thickness of 0.7 mm are taken as the research objects. The feasibility and mechanism of Zn-Al-Mg coated steel plate to solve stamping cracking are verified by using friction testing machine for sheet metal forming and stretching ribs, sheet comprehensive forming testing machine, scanning electron microscope, and MTS nanoindentation testing machine. The results show that the surface friction coefficient of the Zn-Al-Mg coating is 25% lower than that of the pure zinc coating. The forming limit performance of Zn-Al-Mg coated steel plates is better than that of pure zinc coated steel plates. Due to the finer grain size and higher hardness of the Zn-Al-Mg coating, the coating has a lower and more stable surface friction coefficient, which can significantly improve the forming performance of the steel plate and effectively improve the stamping cracking problem of automobile parts.
| 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 |