Investigation on Microstructure and Martensitic Transformation Mechanism for the Warm-Stamped Third-Generation Automotive Medium-Mn Steel
Investigation on Microstructure and Martensitic Transformation Mechanism for the Warm-Stamped Third-Generation Automotive Medium-Mn Steel
复制标题
DOI：
10.1115/1.4037017
复制
发表时间：
2017-10
影响因子：
1.2
通讯作者：
Xiaodong Li;Ying Chang;Cunyu Wang;Han Shuo;D. Ren;P. Hu;Han. Dong
中科院分区：
文献类型：
--
作者：
Xiaodong Li;Ying Chang;Cunyu Wang;Han Shuo;D. Ren;P. Hu;Han. Dong
随着汽车工业的发展，高强度钢的应用成为提高汽车轻量化和安全性的有效途径。本文对第三代汽车用中锰钢（TAMM钢）进行了研究。热冲压TAMM钢具有完整的细晶马氏体组织，没有脱碳层，这有助于获得高且平衡的机械性能。此外，通过膨胀试验研究了TAMM钢的马氏体相变机制。结果表明，在不同载荷下，加载方式对温度的影响是不同的。在拉伸载荷和低压缩载荷下，对温度几乎没有影响。然而，在高压缩载荷下，它略有下降。应变和应变速率对温度的影响不大，可以忽略不计。结果表明，TAMM钢的马氏体相变几乎不受冲压温度、加载方式、载荷、应变和应变速率等工艺参数的影响。根据连续冷却转变（CCT）曲线，可以精确地设计和控制实际冲压工艺，以实现所需的性能，提高汽车零件的成形性。
With the development of the automotive industry, the application of the high-strength steel (HSS) becomes an effective way to improve the lightweight and safety. In this paper, the third-generation automotive medium-Mn steel (TAMM steel) is studied. The warm-stamped TAMM steel holds the complete and fine-grained martensitic microstructure without decarbonization layer, which contributes to high and well-balanced mechanical properties. Furthermore, the martensitic transformation mechanism of the TAMM steel is investigated by the dilatation tests. The results indicate that the effects of the loading method on the Mstemperature under different loads are different. The Mstemperature is hardly influenced under the tensile loads and low compressive load. However, it is slightly decreased under the high compressive load. Moreover, the effects of the strain and strain rate on the Mstemperature are insignificant and can be neglected. As a result, this research proves that the martensitic transformation of the TAMM steel is rarely influenced by the process parameters, such as stamping temperature, loading method, load, strain, and strain rate. The actual stamping process can be designed and controlled accurately referring to the continuous cooling transformation (CCT) curves to realize the required properties and improve the formability of the automotive part.