RESEARCH ON PRODUCTION OF 300 km/h HEAVY RAIL USING CONTINUOUSLY CAST ROUND BLOOM

The manufacturing process of EF steelmaking→LF refining→VD degassing→round concast has been established, by which rail steel round blooms U71Mn and PD₃ have been successfully produced three times. The inspection of round bloom quality suggests that the surface defect-free achieves 100% of total rounds produced from continuous casting. Meanwhile, center looseness is ≤ 1.0, shrinkage cavity is ≤ 0.5, central segregation index of carbon is ≤ 1.07, and the ratio of equiaxed crystal zone is ≥ 40%. The internal quality and mechanical property of experimental rails produced from continuously cast rounds could meet the requirement of 300 km/h high-speed tracks.