| Mold fluxes is a very important and critical material during continuous casting of steel, takes a key role to improve quality of strands. Mold fluxes always became as the bottleneck of technological development of continuous casting (CC) of steel, with the development of CC technology, speeding up of casting velocity, and improvement of strand quality. It is very important to solve the coming technological difficulties in development of mold fluxes for metallurgists, in order to maintain good processes and assure qualities during continuous casting.Under the financial supports of National Planning Committee, National Natural Science Foundation Committee, Chongqing Science and Technology Committee and related companies, the important basic theories and application of mold fluxes concerned with the development of CC have been studied in this paper. The following research works have been finished by author: the effect of components on physical chemistry properties of mold fluxes, coordinated controlling of crystallizing behaviors for mold fluxes, temperature diffusion characteristics of mold fluxes, highly basicity and highly glass properties of mold fluxes, lubrication and frication between mold and strands. On the base of research mentioned above, important basic new theories for mold fluxes have been newly established. According the new developed steel grades and CC caster, a series of mold fluxes have been developed and been successfully applied in most of steel plants in China. The specific researches and the main conclusions are listed as follows:(1) The effect of components, especially the low content components, on melting and flowing properties of mold fluxes have been deeply studied in this paper; the wetting of mold fluxes with TiN inclusion has been also studied; the kinetic behavior of mold fluxes adsorbing Al2O3, TiO2, TiN and RE oxides inclusion were studied in order to understand the inclusion's role in mold fluxes during CC of steel.It is obvious that melting temperature would be increased with the increasing of TiN content in mold fluxes. Because of the weak oxygen potential of mold fluxes, it is nearly impossible to assimilate TiN by mold fluxes. The increasing of MgO, TiO2, Cr2O3 will results in the increasing of melting temperature of mold fluxes, there is a possibility for the formation of high melting CaO·TiO2; meanwhile the formation of forsterite and spinel are also the reasons of melting temperature increasing. In fluxes, Cr2O3 is easy to appear as high melting materials. Of cause, in composition range in the study, Na2O,Li2O,MnO,SrO would force fluxes to form as low melting temperature slag. The lattice energy of SrO is smaller than that of CaO, therefore it has lower melting temperature, when existed in fluxes, low melting temperature composite compounds would be formed, which will result in decreasing of melting temperature of mold fluxes in the situation. MnO has the function of decreasing melting temperature, and would supply O2- ion in fluxes to disintegrate large complex silicate anion as small one, which would also result in the decreasing of mold fluxes viscosity. The effect of TiO2 is unordinary, when the content is smaller than 10%, TiO2 would take as network destroyer, the viscosity would decrease with the increasing of TiO2 in mold fluxes, if the content is exceeded more than 10%, it would take as network former, would take part in forming of composite anion silicate, which would result in enhancing of mold fluxes viscosity. Either for melting temperature or for viscosity of mold fluxes, the effect of TiN would be positive.The mold fluxes would wet TiN well in a wide range of composition, but it is difficult to assimilate TiN inclusion. TiN inclusions would be enriched at the interface of steel and slag. Only at the existence of FeO and MnO, TiN would be transfered as TiO2 and be assimilated homogeneously into mold fluxes.At the range of BaO<13-16%, Na2O<15%, MnO≤6%, B2O≤10%,mold fluxes has high Al2O3 adsorption capacity with the flux such as Na2O, CaF2...
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