According to solidifying and mechanical characteristics of low carbon steel Q235B 230 mm x 1500 mm slab at elevated temperature

a couple thermal and mechanical finite element analysis model for temperature field and stress field of slab during casting process has been established

and the coupling calculation is carried out by using definite element software MSC. Marc. Results show that at present situation the metallurgical length is about 33 m and the length of two- phase region is 16 m； the slab shell transits from compression status to tension status and the complete tension status is at front of inside of shell ； there is spread phenomenon of slab； and the calculated value and measured value all indicate that in simulation condition the real dimension of Q235B steel slab is larger than normal dimension by about 10 mm.