Hot Ductility of Ti-V Bearing Microalloyed Steel in Continuous Casting

Hot ductility of Ti-V bearing steel was studied by theoretical calculation and thermal simulation experiment. Meanwhile, microsegregation and precipitates were analyzed. The results showed that elements S, Ti and O were enriched at the grain boundaries, while the hot ductility was deteriorated by inclusions of (Fe, Mn, Si, Al) (S,O) in the interdendrictic region. At the temperature of 1 100 °C, large TiN particles had little effect on hot ductility. In the temperature range from 975 to 925 °C. reduction of area (R. A) declined rapidly from 81. 88% to 63. 16% with the size of particles decreasing from 40 to 20 nm and quantity increasing from 1.4 to 11. 9 μm−2, respectively. In the temperature range from 875 to 825 °C, R. A reduced unobviously from 35. 14% to 28. 6% with ferric films thickening gradually. The critical stress, 88.79 MPa, was equal to tensile strength at 825 °C. Intergranular fracture was easy to occur with higher critical stress below 825 °C.