连铸坯实测反问题热弹黏塑性建模与分析

Thermal elastic-viscoplastic modelling and analysis of continuous casting slab based on measured inverse problem

为了研究连铸板坯的传热和力学特征,通过建立考虑蠕变的铸坯热弹黏塑性全尺寸有限元数值模型,以实测温度和传热反问题获得的热流为依据,计算和探讨了结晶器内铸坯的传热、应力和应变行为。结果表明,弯月面下100~200 mm铸坯表面承受拉应力,宽面距角部40~90 mm的偏角部区域温度较高,坯壳厚度也较薄,距角部约400 mm处温度相对较低,收缩量及应力应变较大。窄面近角部区域的应力和应变总体上低于宽面,距角部越近,窄面铸坯表面的应变越高。偏角部区域坯壳厚度、应力、应变的非均匀性及存在的过大差异,是探讨近角部裂纹成因需要考虑的重要因素。

Based on heat flux obtained from measured temperature and inverse problem of heat transfer,a full-scale thermal elastic-viscoplastic finite element numerical model considering creep was established to calculate and discuss the thermomechanical behaviors of continuous casting slab in the mold.The results showed that,surface of slab was under tensile stress at position about 100-200 mm below the meniscus.The temperature was higher and thickness of shell was thinner in the area of 40-90 mm away from corner for wide face,it was opposite to which at 400 mm away from the corner.The contraction as while as stress and strain were large in this area.The stress and strain near the corner of narrow face was lower than that of wide face,and surface strain increased with the decrease of distance from corner.The non-uniformity and differences of shell thickness,stress and strain in corner area are the important factors to be considered when discussing the causes of crack near corner.