Research On Continuous Straightening Of Continuous Casting Billet

Straightening billet continuous casting technology is one of the key technologies of efficient continuous casting, the core of efficient continuous casting technology is high speed and high quality of the slab. In the high casting speed conditions, when Straightening of the strand with a liquid center, in order to ensure the two phase region of strain and strain rate control within the allowable values, able to adapt to high casting speed of continuous straightening technology has become the current mainstream technology. To this end, we conduct the following research work.Based on the analysis of heat transfer and solidification deformation in continuous casting, the heat transfer model and the stress-strain model are established in the solidification process of continuous casting slab. And corresponding boundary conditions, thermal performance parameters of the slab and basic mechanical parameters are established, temperature and stress-strain of the casting slab are simulated by finite element software, we can get heat transfer and deformation from the mold to the end of the solidification.In the study of existing continuous straightening curves, the deficiencies of existing straightening curves are pointed out the strain rate of the slab is approximately constant, which did not fully consider the temperature and stress on the slab deformation rate. In the straightening process of continuous casting , high temperature, creep and stress relaxation of billet are significantly, so we can take full advantage of the high temperature deformation characteristics of steel in the design of continuous straightening program. By the knowledge of high temperature creep properties of materials , straightening strain rate of strand is not only related to temperature, but also to the stress of the slab, therefore, Taking full account of effects of stress on strain rate, We can put most of the deformation at high temperature region, thereby straightening technology could be optimized in the continuous straightening zone, and get a new type of continuous straightening curves.Adequately considering of slab creep properties in the high temperature and stress, get a new type of continuous straightening curve by derivating a formula of the curve. The slab strain rate, stress and strain changes of the curve in the straightening zone are more gentle, which can avoid the formation of cracks in casting slab effectively. The exact solution curve is given, which can design and reconstruct a continuous casting machine.