Fe-Mn-Al-C系低密度钢中非金属夹杂物生成及演变行为研究

Fe-Mn-Al-C系低密度钢具有优异的机械性能，是一种具有高轻量化潜力的高强钢，在汽车、船舶以及军事领域有较好的应用前景。低密度钢通过提高Mn、Al含量来满足强度、韧性和轻量化指标，在冶炼过程会产生大量AlN、MnS等夹杂物，而AlN和MnS夹杂物会导致低密度钢塑性恶化。为此，本项目采用理论分析、凝固实验和高温实验等研究方法，研究低密度钢金属熔体中Fe-Mn-Al-C-N-O-S体系中夹杂物平衡关系，明确低密度钢中夹杂物生成条件、形核机制及AlN夹杂团聚机理；研究凝固条件和加热制度对低密度钢中夹杂物类型、尺寸、数量和空间分布的影响规律，揭示凝固和加热过程中夹杂物演变规律，获得适用的冷却条件和加热工艺；提出冶炼-凝固-热处理协同控制低密度钢中夹杂物策略，研究结果可为工业化生产低密度钢提供理论参考，具有重要理论和应用价值。

Fe-Mn-Al-C low density steel has excellent mechanical properties and great potential in lightweight materials, it has extensive application prospects in the fields of automobile, shipping and military. In order to satisfy requirement of strength, toughness and lightweight, the content of manganese and aluminum in steel should be increased. However, AlN and MnS inclusions will be generated in metallic melt during smelting process, and AlN, MnS inclusions are mainly causes of deterioration of plasticity. Based on this background, the present project adopts the combined method including theory analysis, solidification experiments and high temperature experiments, proposes to investigate the formation and evolution mechanism of inclusions in Fe-Mn-Al-C low density steel. This research work is mainly to study inclusion balance in Fe-Mn-Al-C-N-O-S system, and elucidate formation condition and nucleation mechanism of non-metallic inclusions including agglomeration mechanism of AlN inclusion, correlate solidification, heat treatment and the variations of type, size, number and distribution of inclusions, finally obtain applicable cooling condition and heating process. Based on research results, a coordinated control method of non-metallic inclusions during smelting, solidification and heat treatment process may be presented, which has great theoretical importance and applied value for the industrialization of Fe-Mn-Al-C low density steel.