特厚板坯单辊重压下铸坯温度与应力的分析

为获得特厚板坯重压下过程中不同压下量对铸坯温度、应力及应变的影响,从而评估铸坯出现角部以及内部裂纹的倾向,使用板坯连铸二冷软件建立了连铸过程特厚板凝固传热模型,并借助Abaqus有限元软件建立了特厚板单辊重压下应力应变模型,对连铸重压下过程中特厚板温度分布以及应力应变行为进行了数值模拟研究。结果表明,重压下会导致铸坯表面降温,中心温度降幅约为角部的1.4倍。铸坯的应力分布在厚度方向上沿中心呈现出对称性,应力由内、外弧向中心递减;角部区域温度最低,应力最大;压下量从5增加到30mm,铸坯角部最大应力从84增加到170MPa,角部裂纹倾向增加。压下量在5~30mm内,铸坯凝固前沿的最大等效塑性应变均小于临界应变,所以铸坯不会出现内裂纹。

Analysis of slab temperature and stress under single roll heavy pressing for extra thick slab

In order to obtain the influence of different reduction on slab temperature, stress and strain during heavy reduction, and to evaluate the tendency of corner and internal crack, the solidification heat transfer model of ultra heavy plate was established by using secondary cooling software of slab continuous casting, and the stress-strain model of single roll heavy reduction was established by Abaqus finite element software. The temperature distribution and stress-strain behavior of medium and extra thick plate were studied by numerical simulation. The results show that the surface temperature of the slab will be reduced by heavy pressing, and the decrease of the central temperature is about 1.4 times of that at the corner. The results show that the stress distribution of the slab along the thickness direction presents symmetry along the center, the stress decreases from the inner and outer arc to the center, and the temperature in the corner is the lowest and the stress is the largest. When the reduction increases from 5 to 30 mm, the maximum stress in the corner increases from 84 to 170 MPa, and the tendency of corner cracks increases. In the range of 5~30 mm reduction, the maximum equivalent plastic strain at the solidification front of the slab is less than the critical strain, so there is no internal crack in the slab.