Steelmaking flow sheet for steel U76CrRE (/%: 0. 71 〜0. 80C

0. 50 〜0. 80Si

0. 80 ~ 1. 10Mn

0. 04 - 0. 10V

0.25 〜0.35Cr

0. 02RE) and steel U75V (/%: 0. 70 ~ 0. 80C

0. 50 〜0.70Si

0. 75 〜1.05Mn

0. 04 〜 0. 08V) is hot metal pretreatment-150 t top and bottom combined blown converter-LF-VD-280 mm x 380 mm bloom casting

and RE is added in steel by feeding cladding RE wire after LF refining. The simulation test results on hot plasticity of steel casting bloom show that the hot plasticity of V microalloying heavy rail steel is increased by adding RE mainly in 皿 brittle zone

at 950 ~ 1 225 °C the average reduction of area Z value of steel U76CrRE and steel U75V is respectively 83. 34% and 65. 17%

and at 1 250 °C the Z value of steel U76CrRE and steel U75 V is respectively 58% and 12%. In order to prevent forming crack of casting bloom

the strengthening temperature of casting bloom should be ≥900 °C.