板坯连铸结晶器倒角结构和锥度研究

针对板坯连铸铸坯常出现角部横裂纹缺陷，建立了板坯连铸结晶器与铸坯二维瞬态热力耦合有限元模型，研究了板坯结晶器窄面铜板在不同倒角结构和不同锥度情况下铸坯的凝固收缩行为，计算了铸坯在结晶器内的温度和应力分布情况。模型较全面地考虑了保护渣和气隙对传热的影响。数值模拟结果表明：结晶器窄面铜板倒角过大或过小，都不利于铸坯温度的均匀分布；对断面厚度为230mm的铸坯，窄面铜板采用20mm～25mm ×45°;倒角及抛物线锥度时，铸坯表面温度分布最均匀，最大平面主应力分布较合理，角部出现横裂纹的可能性会大大降低。

Chamfer and Taper Researches of Mould in Slab Continuous Casting

Based on the corner transversal cracks in slab continuous casting , the finite element models of two-dimensional transient thermo-mechanical coupled between mould and slab were set up .The solidification shrink-age behavior of slab in the mould with different chamfers and tapers of the narrow face copper was discussed , and the temperature and stress distribution of slabs were calculated .The effect of mould fluxes and air gap on heat transfer was taken into account comprehensively in the models .The numerical results show when the chamfer of mould narrow face copper is too large or too small , it is disadvantage for the uniform distribution of the slab temperature .For the slab of 230mm thickness, the chamfer 20mm-25mm ×45°;and the parabolic taper of the narrow copper plate make the slab surface temperature distribution most uniform and the maximum plane principal stress distribution more rea -sonable , so that the corner transverse cracks will be greatly reduced .