摘要
特厚板坯在浇铸过程中由于窄边鼓肚变形引起液相穴富集溶质钢水流动,传热不均导致严重的中心偏析和中心线状裂纹,同时增加边角部裂纹发生率。因此特厚板坯窄边鼓肚已成为了限制其质量发展的重要因素。本文结合南钢特厚板坯连铸机实际生产工艺,在生产前通过进行扇形段辊缝调整、增强了结晶器与窄边足辊的冷却强度,增加了铸坯坯壳厚度;并通过增加结晶器窄边足辊对数,进行铸坯出结晶器后窄边锥度补偿,延长对铸坯窄边的支撑,减小了钢水静压力对窄边的作用力。通过加强对生产过程中间包钢水过热度与拉速的控制,在结晶器中形成较厚坯壳,有效解决了特厚板坯460/370 mm×(1800~2600)mm断面窄边鼓肚现象,窄边鼓肚单侧鼓肚量控制在5 mm以内,改善了特厚板坯的表面及内部质量。相关研究结果将为未来特厚板的品种研发提供理论基础。
During the casting process,due to the deformation of the narrow side bulge,the liquid phase cavity is enriched with solute molten steel flow,and the uneven heat transfer causes serious central segregation and central linear cracks,and the incidence of corner cracks increases.Therefore,the narrow edge bulge belly of extra thick slab has become an important link to limit the development of quality.Combined with the actual production process of Nanjing Iron and Steel extra thick slab continuous casting machine,the roll gap adjustment of the sector section is carried out before production,the cooling strength of the mold and the narrow side foot roller is enhanced,the thickness of the casting blank shell is increased,the logarithm of the narrow side foot roller of the mold is increased,the narrow side taper compensation is carried out after the casting billet is out of the crystallizer,and the support for the narrow side of the casting billet is extended to reduce the force of the molten steel hydrostatic pressure on the narrow side.By strengthening the control of the superheat and tensile speed of tundish steel in the production process,a thicker blank shell is formed in the crystallizer,which effectively solves the phenomenon of narrow side bulge belly of 460/370 mm×(1800~2600)mm section of extra thick slab,and the amount of unilateral bulge belly of narrow side bulge belly is controlled within 5mm,which improves the surface and internal quality of extra-thick slab,and the relevant research results will provide a theoretical basis for the research and development of extra-thick slab varieties in the future.
作者
钱志友
汪德富
Qian Zhiyou;Wang Defu(First Steelmaking Plant,Nanjing Iron and Steel United Co.,Ltd.,Nanjing 210000,Jiangsu)
出处
《河北冶金》
2023年第10期67-71,共5页
Hebei Metallurgy
关键词
窄边鼓肚
冷却强度
足辊锥度
过热度
拉速
辊缝
narrow side bulge
cooling strength
foot roller taper
superheat
tensile speed
roll gap
