Chamfered mould has gradually become a new technology equipment to eliminate transverse corner crack.However,longitudinal corner crack ratio of chamfered slab was very high.Solidification microstructure was detected i...Chamfered mould has gradually become a new technology equipment to eliminate transverse corner crack.However,longitudinal corner crack ratio of chamfered slab was very high.Solidification microstructure was detected in the area where the longitudinal corner crack occurred.Effect of narrow face shape and taper distribution of mould copper plate on longitudinal corner crack was studied by industrial tests.Water velocity distribution in the narrow copper plate was studied by numerical simulation.On the premise of preventing cooling water from nuclear boiling,improvement measures of mould cooling process and water seam structure were put forward through heat transfer calculation.The results showed that local taper of the meniscus region of mould should be increased to prevent generation of longitudinal corner crack.Chamfering slope length of narrow copper plate should be controlled within 55 mm,and chamfering angle should be controlled at about 30°.Average water velocity should be more than 7.0 m/s.The flat and chamfering regions of narrow copper plate working face should be designed as double taper and funnel structure,respectively.The water seam in the chamfering region should preferentially choose the combined cooling structure with two holes and one slot.In order to prevent the extension of longitudinal corner crack,chamfered narrow face foot roller should be used.展开更多
A transient,two-dimensional,coupled finite element model was employed to simulate the solidification and shrinkage of continuous casting steels by means of ANSYSTM.In the model,a gap-dependent heat transfer condition ...A transient,two-dimensional,coupled finite element model was employed to simulate the solidification and shrinkage of continuous casting steels by means of ANSYSTM.In the model,a gap-dependent heat transfer condition was introduced to modify the heat flux function,and the variations of material thermal properties,mechanical properties as well as the yield function with temperature were considered.The solidification and shrinkage processes of four round billets and two square billets were simulated by indirect coupled method.Simulation results show that carbon content,pouring temperature,casting speed and shape of billets have distinct influence on the solidification shrinkage of billets.Ideal continuous parabolic tapers were designed and optimized according to the calculated shrinkage curves of billets.展开更多
文摘Chamfered mould has gradually become a new technology equipment to eliminate transverse corner crack.However,longitudinal corner crack ratio of chamfered slab was very high.Solidification microstructure was detected in the area where the longitudinal corner crack occurred.Effect of narrow face shape and taper distribution of mould copper plate on longitudinal corner crack was studied by industrial tests.Water velocity distribution in the narrow copper plate was studied by numerical simulation.On the premise of preventing cooling water from nuclear boiling,improvement measures of mould cooling process and water seam structure were put forward through heat transfer calculation.The results showed that local taper of the meniscus region of mould should be increased to prevent generation of longitudinal corner crack.Chamfering slope length of narrow copper plate should be controlled within 55 mm,and chamfering angle should be controlled at about 30°.Average water velocity should be more than 7.0 m/s.The flat and chamfering regions of narrow copper plate working face should be designed as double taper and funnel structure,respectively.The water seam in the chamfering region should preferentially choose the combined cooling structure with two holes and one slot.In order to prevent the extension of longitudinal corner crack,chamfered narrow face foot roller should be used.
基金supported by National Natural Science Foundation of China(No.50601003 andNo.50971032)New Century Excellent Talents in University(NCET-07-0137)Scienti fic Research Fund of Liaoning Provincial Education Department
文摘A transient,two-dimensional,coupled finite element model was employed to simulate the solidification and shrinkage of continuous casting steels by means of ANSYSTM.In the model,a gap-dependent heat transfer condition was introduced to modify the heat flux function,and the variations of material thermal properties,mechanical properties as well as the yield function with temperature were considered.The solidification and shrinkage processes of four round billets and two square billets were simulated by indirect coupled method.Simulation results show that carbon content,pouring temperature,casting speed and shape of billets have distinct influence on the solidification shrinkage of billets.Ideal continuous parabolic tapers were designed and optimized according to the calculated shrinkage curves of billets.
