摘要
The investigation on the behavior of RE in microalloyed steel containing Nb and Ti indicates RE still have the effect of purifying molten steel and metamorphose inclusions even when the composition of S is pretty low(S<0 003%). The optimum performance of the experimental steels can be obtained when w RE / w O+S is controlled around 3 9. The content of solid solution RE can reach 1×10 -5 ～1×10 -4 order of magnitude in ultra low sulfur steel. The additions of RE can reduce the segregation of S and P at the grain boundary, delay the dynamic recrystallization, refine the grain and second phase particles, and promote the precipitation of (Nb, Ti)(C, N). RE also exhibit the microalloying effect in steel.
The investigation on the behavior of RE in microalloyed steel containing Nb and Ti indicates RE still have the effect of purifying molten steel and metamorphose inclusions even when the composition of S is pretty low(S<0 003%). The optimum performance of the experimental steels can be obtained when w RE / w O+S is controlled around 3 9. The content of solid solution RE can reach 1×10 -5 ～1×10 -4 order of magnitude in ultra low sulfur steel. The additions of RE can reduce the segregation of S and P at the grain boundary, delay the dynamic recrystallization, refine the grain and second phase particles, and promote the precipitation of (Nb, Ti)(C, N). RE also exhibit the microalloying effect in steel.
