Analysis and Control Measures on Transversal Crack of Nb Containing Slab

For CC slab,there are many kinds of surface defects which are transversal cracks mainly,Nb containing slab is easy to appear such cracks.Normally,in the bending segment and straightening period of vertical-bending continuous caster,surface and corner transversal cracks will appear in the inner face,corner transversal cracks will appear in the outer surface.The causes of the transversal cracks were analyzed,through measuring temperature and high-temperature mechanical property experiments of S355J2-1 steel with the secondary cooling water distribution.The optimizing measures were put forward and the better results were achieved.