Abstract：In the present work, the morphologies and formation mechanism of inner cracks of continuous casting slab were systematically generalized and investigated. It was found that the formation of inner cracks could be ascribed to two primary reasons: 1) apparatus issues: roller spacing, deformation, bending and straightening method and casting speed etc. 2) controlling issues: casting speed, secondary cooling intensity and thickening of P and S etc. Besides, to reduce the possibility of inner cracks formation, measures should be taken to minimize the whole casting stress, especially to control the bulge of continuous casting slab. Based on the fact, it was suggested that maintaince of the accuracy of continuous casting machine, reduction of the bulging capacity as well as various mechanical stress forced on the shell before solidification to reduce the formation of inner cracks. In summary, the dynamic soft reduction technology which is based on the solidification and shrinkange principle or static roll gap shrinkage technology can be regarded as the most cost-effective measures to control the inner cracks of of continuous casting slab.
2019, Vol. 38 