In order to analyze the evolution of the inclusions in the cold heading steel SWRCH35K during the steelmaking process, a systematic sampling of the steelmaking processes in a steel plant was carried out. Both SEM-EDS ...In order to analyze the evolution of the inclusions in the cold heading steel SWRCH35K during the steelmaking process, a systematic sampling of the steelmaking processes in a steel plant was carried out. Both SEM-EDS and the image processing software Image-Pro-Plus6.0 were employed to analyze the chemical composition, morphology, quantity and size of non-metal inclusions in the steel samples. The results show that from BOF tapping to continuous casting tundish, the composition of inclusions in SWRCH35K steel changes from Al<sub>2</sub>O<sub>3</sub> →MgO·Al<sub>2</sub>O<sub>3</sub> →CaO-MgO-Al<sub>2</sub>O<sub>3</sub>-CaS, and the typical morphology of the inclusions in the steel gradually changes from irregular blocks and clusters to spherical. The number of inclusions in the BOF argon blowing station is the largest, 213#/mm<sup>2</sup>, while the number of inclusions at the end of LF refining is the least, about 12#/mm<sup>2</sup>, and there are basically no inclusions above 5 μm. In addition, LF calcium treatment will adversely affect the size and quantity control of inclusions in steel. In order to effectively reduce the large-size calcium-containing spherical oxide inclusions in cold heading steel, it is necessary to find a technical method that can replace LF calcium treatment to solve the problem of molten steel continuous casting.展开更多
为推动钢渣在道路工程中的应用,缓解钢渣堆放造成的土地占用与环境污染问题,对钢渣陈化过程中的理化特征及钢渣沥青混合料性能进行了研究。采用粒度粒形、X射线荧光光谱试验探究钢渣陈化前后的形貌特征和矿物组成。随后,利用未处理钢渣...为推动钢渣在道路工程中的应用,缓解钢渣堆放造成的土地占用与环境污染问题,对钢渣陈化过程中的理化特征及钢渣沥青混合料性能进行了研究。采用粒度粒形、X射线荧光光谱试验探究钢渣陈化前后的形貌特征和矿物组成。随后,利用未处理钢渣、陈化钢渣和玄武岩制备了沥青混合料,对比评价了3种沥青混合料的体积膨胀性、水稳定性、高温稳定性和低温抗裂性能。此外,通过灰色关联法分析了集料特性与混合料性能的关联性。结果表明,钢渣的高粗糙度、高棱角性使其成为玄武岩等天然集料的理想替代品。然而,未陈化钢渣体积稳定性差,遇水易膨胀,导致无法满足路面使用要求。值得注意的是,CaO和Fe 2 O 3含量是影响钢渣体积稳定性的重要因素,而陈化处理可以在一定程度上降低这些负面影响,从而改善钢渣沥青混合料的路用性能。综合各项分析,陈化钢渣沥青混合料具有较好综合路用性能,钢渣的二次利用对于实现道路基础设施的可持续发展具有重要意义。展开更多
文摘In order to analyze the evolution of the inclusions in the cold heading steel SWRCH35K during the steelmaking process, a systematic sampling of the steelmaking processes in a steel plant was carried out. Both SEM-EDS and the image processing software Image-Pro-Plus6.0 were employed to analyze the chemical composition, morphology, quantity and size of non-metal inclusions in the steel samples. The results show that from BOF tapping to continuous casting tundish, the composition of inclusions in SWRCH35K steel changes from Al<sub>2</sub>O<sub>3</sub> →MgO·Al<sub>2</sub>O<sub>3</sub> →CaO-MgO-Al<sub>2</sub>O<sub>3</sub>-CaS, and the typical morphology of the inclusions in the steel gradually changes from irregular blocks and clusters to spherical. The number of inclusions in the BOF argon blowing station is the largest, 213#/mm<sup>2</sup>, while the number of inclusions at the end of LF refining is the least, about 12#/mm<sup>2</sup>, and there are basically no inclusions above 5 μm. In addition, LF calcium treatment will adversely affect the size and quantity control of inclusions in steel. In order to effectively reduce the large-size calcium-containing spherical oxide inclusions in cold heading steel, it is necessary to find a technical method that can replace LF calcium treatment to solve the problem of molten steel continuous casting.
文摘为推动钢渣在道路工程中的应用,缓解钢渣堆放造成的土地占用与环境污染问题,对钢渣陈化过程中的理化特征及钢渣沥青混合料性能进行了研究。采用粒度粒形、X射线荧光光谱试验探究钢渣陈化前后的形貌特征和矿物组成。随后,利用未处理钢渣、陈化钢渣和玄武岩制备了沥青混合料,对比评价了3种沥青混合料的体积膨胀性、水稳定性、高温稳定性和低温抗裂性能。此外,通过灰色关联法分析了集料特性与混合料性能的关联性。结果表明,钢渣的高粗糙度、高棱角性使其成为玄武岩等天然集料的理想替代品。然而,未陈化钢渣体积稳定性差,遇水易膨胀,导致无法满足路面使用要求。值得注意的是,CaO和Fe 2 O 3含量是影响钢渣体积稳定性的重要因素,而陈化处理可以在一定程度上降低这些负面影响,从而改善钢渣沥青混合料的路用性能。综合各项分析,陈化钢渣沥青混合料具有较好综合路用性能,钢渣的二次利用对于实现道路基础设施的可持续发展具有重要意义。
