中文摘要：

连铸结晶器振动冲击对连铸坯初始裂纹形成影响显著。研究考虑弯月面初凝坯壳为简支梁,基于材料力学理论和非正弦振动波形分析结晶器振动周期典型时刻初凝坯壳凝固前沿受渣道压力和钢水静压力所形成非均布载荷时的力学状态,进而定量分析初始裂纹的形成可能,并计算振动参数变化对初凝坯壳受弯曲应力的影响,以阐明控制初始裂纹工艺措施。研究表明,弯月面初凝坯壳垂直拉坯方向最大弯曲应力可达148.4 k Pa,而固相分率为0.9的固态坯壳临界断裂应力仅为14.7 k Pa,极易使得初凝坯壳凝固前沿产生初始裂纹;振频、振幅各降低75 min^-1、1.5 mm,非正弦振动因子增大0.15时,最大弯曲应力值分别减小约36.3、24.6、16.4 kPa;适当降低振频和振幅,增大振动因子可抑制坯壳初始裂纹的形成。

英文摘要：

The formation of initial cracks on continuous casting slabs is greatly effected by the vibration of the mold. The initial solidifying shell in the meniscus was considered as simple beam in this study, and the stress states under the non-uniform loads by ferrostatic pressure and flux channel pressure was expatiated in solidification front at representative oscillation time based on the material mechanics theory and non-sinusoidal oscillation waveform, the possibility of generating initial cracks were discussed quantitatively, and the measures for controlling initial cracks were proposed in combination with the rule of influence of oscillation parameters on bending stress. The results show that the maximum bending stress in initial solidifying shell can reach to 148.4 kPa in vertical direction, the initial cracks generated easily because of the critical fracture stress is 14.7 kPa when the solid fraction increased to 0.9. The maximum bending stress decreases about 36.3,24.6, 16.4 kPa when the vibration frequency and the amplitude have a reduction of 75 min^-1, 1.5 mm, and the oscillation factor increases by 0.15. The initial cracks formation can be restrained by decreasing oscillation frequency and amplitude and increasing non- sinusoidal oscillation factor properly.