Research On Deformation Behavior Of Thin Slab Mold With High Speed

In the thin slab funnel mold,the shape of the cavity of the mold changes continuously from top to bottom,and the primary slab shell is subjected to additional extrusion and casting during the descending process.The wide-faced copper wall brings forced deformation to the high-temperature slab shell,resulting in more complicated solidification and stress state.Under the condition of high casting speed,the mold lubrication,heat transfer and deformation behaviors significantly restrict the continuous casting and the quality of the slab.Based on the nodal temperature inheritance and contact algorithm,a threedimensional slab heat transfer and stress coupling model in the FTSC thin slab funnel mold was created to analyze the solidification and deformation behavior of the primary slab shell during the downward movement.Under the condition of fixed cavity shape of the mold,the effects of process factors such as casting speed,narrow face taper and slab width on the heat transfer of the slab and the deformation behavior of the slab shell were systematically studied.The contact state between the slab shell and the funnel mold is revealed.The research indicates:The initial slab shell is in close contact with the copper wall of the mold.At 600 mm from the meniscus,the corner region gradually generates and grows air gaps.Under typical casting conditions,the air gap at the corner of the mold outlet reaches 0.195 mm,and the face area is always in good contact.Increasing the casting speed and increasing the taper can reduce the air gap at the corner,and the increase in the slab width makes the air gap at the corner thicker.The first principal stress in the corner region of the slab is the highest,which increases first and then decreases along the slab casting direction,and forms a peak at600 mm below the meniscus.Under the typical casting process,the first principal stress at the corners is up to 36.9 MPa.The first principal stress in the slab shell face area shows a gradually increasing trend.With the increase of casting speed and the taper of the narrow face,the first principal stress of the slab shell increases gradually.Increasing the width of the slab reduces the first principal stress of the slab shell.In the funnel area on the upper part of the mold,the downward slab shell is pressed by the copper wall of the mold,and the slab shell in the funnel area tends to shift toward the corner in the horizontal direction.As the slab shell goes down,the curvature of the funnel area decreases,the effect of the solidification shrinkage of the slab shell on its moving direction is prominent,and the moving direction of the slab shell changes.Under typical casting conditions,about 500 mm from the meniscus,the slab shell starts to move towards the funnel area.At the outlet of the mold,the slab shell is offset by 1.79 mm towards the funnel area.As the casting speed increases,the excursion of the slab shell to the funnel area is delayed and the displacement decreases.Increasing the taper of the narrow face will increase the offset of the slab shell towards the funnel area.The change of slab width has little effect on the displacement of slab shell.Figure 48;Table 7;Reference 56...