Study On Comprehensive Deformation Of Straightening Zone Of Continuous Casting Slab

Cracks in continuous casting slabs have always been an important factor affecting the efficient production of continuous casters.In the whole hot charging and hot delivery process of continuous casting slabs,the existence of cracks in continuous casting slabs will reduce the quality of products and deteriorate the mechanical properties of products,resulting in huge waste of energy and iron and steel resources.The main factor affecting the crack of continuous casting slab is the unreasonable stress.Especially in the straightening area,the straightening,bulging and roll dislocation of continuous casting slab cause the change of the stress environment of continuous casting slab,and then affect the comprehensive deformation of continuous casting slab.It is easy to cause the crack of continuous casting slab.It is of great theoretical and practical significance to improve the quality of continuous casting slab by reasonably setting rollers,optimizing the design parameters of continuous caster,developing new straightening curves,minimizing the stress and strain rate of slab in straightening zone and controlling them within the safe range.Based on the mechanical properties of continuous casting slab at high temperature,the theory of slab straightening and the comprehensive deformation of slab in straightening zone are studied in this paper.Based on the viscoplastic constitutive equation of high temperature continuous casting slab by power function straightening method,a new mathematical model of straightening deformation of high temperature continuous casting slab is established.On this basis,the constitutive equation of high temperature elasticity is added.The straightening curve of new type continuous casting slab is derived,and a new straightening method,power function straightening,is proposed.Direct method.The rollers of the new power function straightening method are arranged according to the straightening curve of its mathematical model,which fully satisfies the deformation law of high temperature viscoelastic-plastic continuous casting slab,makes the deformation curve of continuous casting slab the same as that of straightening,reduces the stress and strain rate of continuous casting slab in the whole straightening zone,and reduces the comprehensive variation of continuous casting slab.Shape,control continuous casting slab cracking.Based on the viscoplastic constitutive equation of high temperature continuous casting slab by power function straightening method,a new mathematical model of straightening deformation of high temperature continuous casting slab is established.On this basis,a new mathematical model of dynamic bulging deformation of continuous casting slab shell is established by adding the constitutive equation of high temperature elasticity.Combined with hydrostatic pressure of molten steel,mould friction,shell deformation,wide and narrow support and other factors,the validity of the model and the correctness of the theoretical solution are verified by means of finite element model,and the dynamic bulging deformation law of continuous casting slab shell in straightening zone is given.The finite element simulation analysis model of bulging deformation of continuous casting slab shell is established.The deformation of continuous casting slab in the process of new power function straightening is simulated.The stress and strain of different positions in straightening zone of continuous casting slab are analyzed.Finally,the relationship between stress and deformation of slab section is obtained,and the number of new power function straightening is calculated.The learning model is validated.