THE EFFECT OF PHOSPHORUS AND SULFUR ON THE CRACK SUSCEPTIBILITY OF CONTINUOUS CASTING STEEL

摘要

Based on the coupled macro-heat transfer and micro-segregation model for continuous casting wide-thick slab, the effect of phosphorus and sulfur on crack susceptibility was investigated from the peritectic reaction zone, the brittle temperature range, the thermal strain and the difference of deformation energy. The results show that the crack sensibility of continuous casting steel, especially the hypo-peritectic steel, intensifies with the improvement of phosphorus and sulfur in steel matrix. Compared with phosphorus, sulfur does a more powerful effect on the crack susceptibility of steel. The peritectic reaction zone, the brittle temperature range and the thermal strain are capable to characterize the influence of phosphorus and sulfur on the crack susceptibility of steel. However, the calculated difference of deformation energy decreases with increasing phosphorus and sulfur, which is inconsistent with the experiment results. Therefore the difference of deformation energy is inappropriate to be applied to characterize the impact of phosphorus and sulfur to crack susceptibility of steel.