Abstract: HRB400 high strength reinforcing steel (% ： 0. 19 ~0. 25C, 0. 40 ~0. 60Si, 1. 20 ~ 1.50Mn, ≤0.040P, ≤0. 040S) is melted by 120 t BOF-ladle argon blowing-120 mm x 120 mm billet casting process. In order to improve the comprehensive mechanical properties of Φ 12 ~22 mm ribbed bar of hot-rolled HRB4CX) steel the three kinds of microalloying process tests i. e. adding 5 kg/1 MnSiN + 0. 4 〜0. 9 kg/t FeV, 10 kg/t MnSiN + 0. 25 ~ 0. 40 kg/t FeNb and only adding 0. 40 ~0. 75 kg/t VN have been carried out during steelmaking. The pitting temperature of billet is 1 150 ~ 1 250 °C, the finishing rolling temperature for reinforcing steel bar is ≥950 °C, reduction of each pass in rough rolling ≥30% and reduction of each pass in finishing rolling ≥15%, fanning cooling after rolling. Results show that the available adding amount of FeV or VN is 0. 5 kg/t and that of FeNb is 0. 3 kg/t; with microalloying by V or Nb, the grain in steel is finer obviously and each property of reinforcing steel meets the requirement of standard.

摘要： HRB400高强度钢筋(%:0.19～0.25C、0.40～0.60Si、1.20～1.50Mn、≤0.040P、≤0.040S)由120 t转炉-钢包吹氩-120 mm×120 mm连铸工艺冶炼。为提高HRB400Φ12～22 mm热轧带肋钢筋的综合力学性能,冶炼时进行加5 kg/t_钢MnSiN+0.4～0.9 kg/t_钢FeV,10 kg/t_钢MnSiN+0.25～0.40 kg/t_钢FeNb和只加0.40～0.75kg/t钢VN三种微合金化工艺试验。钢坯均热温度1150～1250℃,终轧温度≥950℃,粗轧每道次压下量≥30%,精轧每道次压下量≥15%,轧后风冷、结果表明,合适的FeV或VN加入量为0.5 kg/t_钢,合适的FeNb加入量为0.3 kg/t_钢,经V或Nb微合金化后,钢中晶粒明显细化,各项性能满足标准要求。