Effect of the strand corner structure on the corner stress during the bending and straightening processes in slab continuous casting

Abstract

The complexity of thermal and mechanical stresses during bending and straightening processes may cause cracks around strand corners. To analyze the thermal and mechanical behaviors around a strand corner in the secondary cooling zone, a three-dimensional thermo-elastoplastic finite element model that couples the slab and rollers with different corner structures (right-angle, big-chamfered, multi-chamfered and fillet) is established. The temperature variation is indirectly coupled through a combined three- and two-dimensional hybrid heat transfer slab model. The results indicate that all three types of chamfered structures can maintain the corner temperature of strands, avoiding the formation of a low-temperature ductility zone at the straightening segment. The stress concentration is very significant around the strand corner. During the bending and straightening processes, the stress of the strand continues to accumulate. Although all three types of chamfered structures can reduce the stress concentration, the big-chamfered structure cannot effectively decrease the peak stress at the strand corner. The effects of the multi-chamfered and fillet structure are more remarkable.