Abstract: The 1215 free cutting steel is successfully developed by 120 t converter-120 t LF-180 mm x 180 mm billet casting high-speed wire rolling flowsheet. The key control point is converter tapping steel C ;0.05% , converter end temperature 1630 ~1660 °C , refining free oxygen control target 50 x 10 ^-6 ~ 55 X 10 ^-6, and binary slag basicity 2.5 ~ 3.0. The composition design is 0.05% 〜0.07% C, 1.20% 〜1.35% Mn, and 0. 340% 〜0. 360% S. On this process conditions ,the morphology and content of sulfide in steel are controlled reasonably. The Mn/S is beneficial to the rolling and improving cutting performance of free cutting steel. The superheat of molten steel is controlled within 25 〜40℃ and the casting speed is 1.2 m/min. It shows that accurately predicting the end-point oxygen content to determine the amount of deoxidizer added, and reasonable control of the oxygen content of different processes are the key to achieve stable quality control of wire products.

摘要： 成功开发了1215易切削钢120 t转炉-120 t LF-180mm×180mm连铸-高线轧制生产工艺。关键控制点为:转炉出钢C <0.05%、转炉终点温度1630～1660℃、精炼自由氧控制目标50×10^-6～55×10^-6,炉渣二元碱度2.5～3.0。设计成分（/%）为:0.05～0.07C,1.20～1.35Mn、0.340～0.360S,该工艺条件下钢中硫化物形貌和含量控制合理,Mn/S有利于易切削钢的轧制和改善切削性能。钢水的过热度按25～40℃控制,拉速1.2 m/min。实践表明,准确预判终点氧含量以确定脱氧剂加入量,合理控制不同工序的氧含量是达到线材产品质量稳定的关键。