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在弧形连铸机上用变更浇铸条件的方法研究了二次冷却、电磁搅拌制度和拉辊压力对250毫米厚的碳钢板坯中轴向偏析的影响。为了测定铸坯液芯凹面形貌,曾在浇铸时加入铅。确认,W型凹面将导致铸坯中钢水的密度和碳含量的变化。当二次冷却强度增大并在低于结晶器中钢水弯月面2.5米处使用电磁感应器时,轴向偏析将显著地减少。通过测量凹面底部区域铸坯厚度的变化,研究拉辊压力对预防板坯凸肚的影响。由于采用了连铸机,目前已有可能实现浇铸操作机械化和改善劳动条件。连铸工艺的不断完善为大量地扩大连铸钢的品种提供了可能。目前,日本铜管株式会社拥有四台弧型板坯连铸机(共7流),月生产能力为30-32万吨,浇铸21-23％不同牌号的钢水,其中有深拉延用的铝镇静冷轧板和高强度管钢。但是直到目前为止还存在连铸坯中心偏析问题。虽然中心偏析对连铸坯轧成的厚板机械性能不呈现“致命的”的影响,但是由此而产生的显微偏析,会引起钢质不均性,因而必须予以完全排除。本文阐述二次冷却制度和机械因素对连铸坯轴向偏析的影响。
The effects of secondary cooling, electromagnetic stirring system and draw roll pressure on the axial segregation in a 250 mm thick carbon steel slab were investigated by changing casting conditions on an arc caster. In order to determine the concavity of the wick, the lead was added during casting. It was confirmed that the W-shaped concavities would result in changes in the density and carbon content of molten steel in the slab. Axial segregation will be significantly reduced when the secondary cooling strength increases and electromagnetic sensors are used at 2.5 meters below the meniscus of the molten steel in the mold. By measuring the change of the thickness of slab in the bottom of concave surface, the influence of drawing roller pressure on the prevention of slab bulging is studied. Thanks to the continuous caster, it is now possible to mechanize the casting operation and to improve working conditions. Continuously improve the continuous casting process for the large-scale expansion of continuous casting of steel provides the possibility. At present, Nippon Brass Pipe Co., Ltd. has four arc-shaped slab caster (a total of seven streams), the monthly production capacity of 30-32 tons, casting 21-23% of different grades of molten steel, including deep drawing Cold-rolled aluminum plate and high-strength steel pipe. But so far there is still the problem of segregation of the center of the slab. Although center segregation does not have a “lethal” effect on the mechanical properties of slab rolled slabs, microscopic segregation resulting therefrom can cause steel unevenness and must therefore be completely eliminated. This paper describes the secondary cooling system and mechanical factors on the impact of the axial slab segregation.