STUDY ON SURFACE FINE CRACKS OF SHIPBUILDING STEEL PLATE CONTAINING Nb AND Ti

The formation mechanism of surface fine cracks of shipbuilding plate containing Nb and Ti was studied The results show that the surface fine cracks are not developed but propagated in rolling process The surface fine cracks are formed in the mould along the crystal grain boundary The contents of Nb, Al and Cu etc in the steel are the main factors that affect the formation of surface fine cracks