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通过温度场、流场和应力场的三场耦合,对某铝业公司AA7050铝合金铸锭在半连铸过程中3种不同起始铸造速度下的应力、应变分布进行了数值模拟研究。结果显示,铸锭心部呈现很大的三轴拉应力,表面则呈现明显的压应力。根据在糊状区环向和径向的应力、应变分量较大,而轴向应力、应变分量较小,可以预计热裂纹倾向平行于轴向分布,不太可能发生垂直于轴向的热裂纹。铸造时在起始铸造阶段有必要采用小的铸造速度,以降低糊状区的热应力、应变,减小开裂倾向。
Through three couplings of temperature field, flow field and stress field, the stress and strain distributions of AA7050 aluminum alloy ingot in an aluminum company during three different initial casting speeds in the process of semi-continuous casting were numerically simulated. The results show that the heart of the ingot presents a large triaxial tensile stress, while the surface shows obvious compressive stress. According to the toroidal and radial stress in the mushy zone, the strain component is larger and the axial stress and strain components are smaller, the tendency of the hot crack to be parallel to the axial distribution is predicted, and it is unlikely that the perpendicular to the axial hot crack . Casting in the initial stage of casting necessary to use a small casting speed to reduce the mushy zone thermal stress, strain, reduce the tendency to cracking.