CAUSES AND MEASURES OF EDGE CRACKS IN MEDIUM AND THICK PLATES
After the improvement of slab caster equipment,the proportion of edge cracks of steel plate increased abnormally,and the analysis on the microstructure of the cracks shows that the edge cracks of steel plates originate from the billet.The comparison and analysis of the surface morphology of continuous casting billet,the protective slag,the composition of the molten steel,mold cooling,equipment maintenance and mold vibration parameters were conducted.The results show that the four corner vibration marks of continuous casting billet are not uniform,irregular,sometimes disordered and irregularly distributed,so the unreasonable mold vibration parameters and poor continuous casting machine working conditions are the main causes of the edge cracks.By adjusting the starting position of mold vibration to the middle position,extending the ramping time of amplitude change,and improving the working conditions of continuous casting machine,the ratio of crack at the edge of the steel plate is reduced from 5％～50％to less than 1％.
Edge crackOscillation marksMold oscillationPrecision of equipmentIntermediate positionRamping time
NETL
NSTL
万方数据
