Microstructure Analysis of High-Manganese TWIP Steels Produced via Strip Casting
Microstructure Analysis of High-Manganese TWIP Steels Produced via Strip Casting
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DOI：
10.4028/www.scientific.net/kem.554-557.553
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发表时间：
2013-06
期刊：
影响因子：
--
通讯作者：
M. Daamen;S. Richter;G. Hirt
中科院分区：
文献类型：
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作者：
M. Daamen;S. Richter;G. Hirt
锰含量超过20%的钢提供了新的和有利的材料性能组合，如高强度和高延展性。这些非凡的机械性能是基于Tensor效应，这取决于堆垛层错能（SFE）。但是，在高锰钢的常规生产中仍然存在问题，这阻碍了它们的广泛应用。在铸造和随后的热轧中都出现困难，结果是生产非常昂贵。高锰钢的一种替代生产工艺是薄带连铸，其基本可行性已在早期工作中得到证实。带坯连铸允许在一个组合过程中铸造和轧制热带材。以这种方式，可以生产厚度小于3mm的热轧带。带材铸造材料的特征是具有细枝晶结构的铸态结构，其显示出具有短波长的显著的微偏析。明显的微观偏析可以对局部化学成分产生影响，从而对发生的主要形成机制产生影响。因此，在这项工作中，薄带铸造材料的显微偏析的电子探针（EPMA）测量的手段进行了研究。除局部元素分布外，还分析了非金属夹杂物的存在和成分。特别是来自铸造工艺的氧化物和来自原材料的硫化物。此外，不同的退火工艺消除枝晶铸态组织进行了检查。在这些实验中，温度在900至1150°C的范围内变化，退火时间从几分钟到几小时。
Steels with manganese contents of more than 20% offer a new and favourable combination of material properties like high strength and high ductility. These extraordinary mechanical properties are based on the TWIP effect, which depends on the Stacking Fault Energy (SFE). But there are still problems in the conventional production of high-manganese steels, which prevents their widespread use. Both in casting and subsequent hot rolling difficulties occur, with the consequence that the production is very expensive. One alternative production process of high-manganese steels is strip casting, which basic feasibility was shown in earlier work. Strip casting allows the casting and rolling of hot strip in one combined process. In this way hot strip with a thickness of less than 3 mm could be produced. Characteristic for the strip cast material is the as-cast structure with a fine dendritic structure, which shows pronounced microsegregations with a short wavelength. The pronounced microsegregations can have an impact on the local chemical composition and thus on the dominating forming mechanisms that occur. In this work therefore the microsegregations of strip cast material are investigated by means of electron probe microanalysis (EPMA) measurement. Besides the local element distribution, also the presence and composition of non-metallic inclusions are analysed. Especially oxides from the casting process and sulfides from the raw material are expected. Furthermore, different annealing processes for the elimination of the dendritic as-cast structure are examined. In these experiments the temperatures were varied in the range from 900 to 1150°C at annealing times from several minutes to a few hours.