In order to resolve surface crack resulting from the casting thermal stress during the continuous casting ZF steel slabs

a geometric-physical model was established

in which the combination of the Adstefan software with temperature field measured actually was considered. Filling and solidification of the ingots were simulated by the model at different over-heating degrees

different drawing velocities and different tapers of the mould to observe the stress distribution in the slabs. The results reveal that with increasing in drawing velocities

thermal stress in the billet shell is decreased. However

excessive high drawing velocity can lead to thin the thickness of the shell

easily resulting in the leakage of liquid steel

even more the occurrence of reunion

so the surface crack would occur in the slabs during rolling process. With increasing in drawing velocities

leakage of liquid steel and reunion should be controlled as possible. With increasing in over-heating degree

thermal stress in the shell is increased

so during production

over-heating degree should be decreased as possible to decrease thermal stress. Meanwhile

with increasing in taper of mould

thermal stress in the shell is increased

so during production

proper taper of mould should be considered to decrease the thermal stress. At the same conditions

the thermals tress in the corner of the shell is evidently higher than that in the other positions. Camber angle can be adopted in design of the mould to effectively decline the thermal stress in the shell. In addition

effects of drawing velocity on thermal stress are higher than over-heating degree.