Abstract:Aiming at the problem of forging crack caused by the intermediate crack of Q345B continuous casting slab with 280 mm×2 000 mm size in TISCO, the forming mechanism of intermediate crack was analyzed by means of macro inspection and model calculation. On this basis, the solution measures of Q345B crack defect were proposed, which provided technical support for reducing the crack defect rate of forging material. The results show that the main influencing factor for the middle crack of Q345B slab is the precision of roll gap, and the continuous casting process parameters are also important conditions for the formation and propagation of slab cracks. In view of the above reasons, the process of improving roll gap accuracy, reducing superheat and increasing secondary cooling intensity can improve the equiaxed grain quality and basically eliminate the intermediate crack defects. The development of F-EMS process can fundamentally improve the internal quality and thoroughly solve the problems of intermediate cracks.