【作者】 汪宁； 孟祥宁； 朱苗勇；

【Author】 Wang Ning;Meng Xiangning;Zhu Miaoyong;School of Metallurgy,Northeastern University;

【机构】 东北大学冶金学院；

【摘要】 连铸结晶器弯月面处初凝坯壳强度较小,易受力发生形变,产生初始缺陷。本文通过对弯月面处初凝坯壳建立力学模型,对初凝坯壳所受摩擦力进行分析计算,提出了新的初始裂纹形成机理。研究表明,周期性变化的渣道压力使初凝坯壳发生形变,进而改变其所受摩擦力。在振动正滑脱时期,弯月面处初凝坯壳所受摩擦力为液态摩擦力,振动负滑脱时期,当初凝坯壳形变量过大,液态摩擦力转为固态摩擦力,铸坯表面初始裂纹生成于振动负滑脱中期。提高振频、振幅,降低拉速,会使初凝坯壳所受最大摩擦力增加,增大初始裂纹生成的可能。更多还原

【Abstract】 Initial solidifying shell in meniscus is likely to deform because of the low strength.In this study,a mechanical model of meniscus shell was developed for analyzing the friction behavior,and a new mechanism of crack formation was expounded.The results show that the solidifying shell changed its shape periodically by the channel pressure and the friction also changed simultaneously.The friction during positive strip time was liquid friction.Liquid friction could be transformed into solid friction if the deformation of solidifying shell was large enough during the negative strip time.The initial crack was formed during the half of negative strip time.The maximum friction was enhancing with the higher frequency and amplitude of mold,and the lower casting speed played the same role.They all increased the possibility of initial crack更多还原