低温度梯度结晶器铜管的设计及工业试验

Design and industrial application trial for low temperature gradient mould copper tube

设计和制造了可用于降低钢液凝固前沿温度梯度的带隔热镀层的新型结晶器,并在方坯连铸机上进行了工业试验,分析了其对方坯凝固组织的影响。结果表明,低温度梯度结晶器可满足连铸生产要求;与传统结晶器相比,低温度梯度结晶器出口铸坯表面温度提高了108℃,相近拉速下该结晶器的平均热流密度相对更低,表明其减缓了钢液在凝固初期的传热,从而降低了凝固前沿的温度梯度;通过与低过热度、电磁搅拌技术相结合,低温度梯度结晶器生产的铸坯等轴晶率提高了8%~13%,中心偏析和缩孔严重程度明显降低。

A new mould with heat insulation coating capable of decreasing the temperature gradient of the solidification front is designed,manufactured and tested in a billet continuous caster in industrial scale.Results show that the mould with low temperature gradient can meet the production demand of continuous casting.In comparison with the traditional one the low temperature gradient mould possesses following advantages： the surface temperature of the exit billet rises by 108 ℃ and under the condition of similar drawing speed the average heat flux density is relatively low.All facts show that the new mould can effectively slow down the heat transfer of the liquid steel at the initial stage of solidification and thus lower the temperature gradient at the solidification front.In combination with low overheat and electromagnetic stirring technologies adopted the equiaxed grain ratio of the billets produced by the low temperature gradient mould rises by 8 %~13 % and the central segregation and cavitation are prominently reduced.