关键词: 45Mn2R硫系易切削钢, ≥ 40%铁水-50 t EAF-LF-VD-CC流程, 硫化物控制, 洁净度

Abstract: The 45Mn2R steel Φ40-50 mm rolled product is developed by ≥ 40% hot metal- 50 t EAF-LF-VD-180 mm x 220 mm cast billet-rolling flow sheet. The cleanliness and casting ability are improved by controlling EAF end [C] ≥ 0.10% ,[P] ≤ 0.015% , tapping temperature 1 620-1 660 °C , preliminay deoxidation using " recaburizing agent + (15%Ca-12%Al-45%Si) compound deoxidation reagent + (50%CaO-34%A1₂O₃-4%MgO) synthetic slag" during tapping, S content in metal ≤ 0.010% before Ca treatment, feeding S wire after Ca treatment for 20 min, soft blowing for 20 min after VD etc process measure. Results show that produced 45Mn2R steel (/% : 0.43-0.46C, 0.22-0.27Si, 0.009-0.017P, 0.065-0.086S, 0.32-0.36Cr, 0.003-0.010Ti, 0.013-0.034AIs) has better comprehensive properties to meet user requirement.

Key words: 45Mn2R Sulfur Free-Cutting Steel, ≥ 40% Hot Metal-50 t EAF-LF-VD-CC Flowsheet, Sulphide Control, Cleanliness