Study On Mold Fluxes For Cr13 Martensitic Stainless Steel Billet

In order to solve surface depression and cracks on Cr13 stainless steel billet in Panchanggang I&S Co., domestic and overseas application of mold fluxes for stainless steel has been investigated., effect of mold fluxes and continuous casting process on surface quality of billet has also been studied. Considering the properties and performances of stainless steel at high temperature, the characteristics of Cr13 stainless steel billet casting, the parameters of continuous caster and manufacturing process in Panchanggng I&S Co., a research of mold fluxes used in Cr13 stainless steel billet casting has been carried out.①The DIL402C thermal dilatometer, STA449C thermal analyzer, the type Gleeble-1500D thermal simulation testing machine were employed to test the linear expansion coefficient, major phase change temperature, mechanic properties at high temperature of 2Cr13. The effect of these properties at high temperature on surface quality of billet and the mechanism of surface depression and crack formation on billet were analyzed. The study showed that heat transfer performance of mold fluxes for Cr13 stainless steel was vitally important.②Considering the requirement of mold fluxes for Cr13 stainless steel billet casting, the slag system of CaO-SiO2-Na2O-F--MgO-BaO-MnO-Al2O3 was designed. The bacisity of fluxes is 0.65～1.05. Na2O%, F-%, MgO%, BaO%, MnO% in mold fluxes were respectively controlled in 4～12%, 0～4%, 0～6%, 0～8%, 0～6%, and Al2O3% is arranged in 1%. The relationships between components and melting temperature, viscosity, breaking temperature had been studied.③The simulation setting used for testing coefficient of temperature conductivity was designed and used to study relationship between coefficient of temperature conductivity of mold fluxes film and temperature. By utilizing the X-ray diffractometer and microscopicexamination, the mineralographic composition and microscopic characteristics of mold fluxes film obtained from simulation setting were investigated in detail. The effect of components on microscopic characteristics and heat transfer performance of mold fluxes film has been analyzed.④The research results suggested that the chemical compositions of mold fluxes for Cr13 stainless steel billet casting in Panchanggang I&S Co. could mainly consist of CaO, SiO2, Na2O, CaF2, MgO, MnO. The basicity( R= [(∑CaO)/SiO2] ) can be...