Abstract: The production process of Φ 14 mm products of steel HRB400 (/% : 0. 21 ~0. 25C, 0. 35 ~0. 60Si, 1.30 - 1.55Mn, 0.045P, 0.045S) is 100 t BOF-argon blowing-150 mm x 150 mm billet casting-rolling. In order to resolve the cold-bending cracking phenomenon by increasing yield strength of steel HRB400 besides higher C and Mn content in steel, the commercial pilot production by adding titanium nitride for Ti microalloying and optimizing control rolling-cooling process is carried out. Results show that with decreasing Mn and Si content (/% ) in steel respectively by 0. 35 and 0. 1, and adding 0. 007% Ti in steel (test No2) , or controlling steel reinforced bar going to cold bed temperature at 670 ~ 690 °C (test No2 ) , the yield strength of finished reinforced bar is up to 460 MPa the test aim value ； as using Ti microalloying and optimizing cooling process (/% : 0. 22C, 0. 34Si, 1. OOMn, 0. 007Ti and going to cold bed temperature at 670 ~ 710 °C , test No3) the average yield strength R_el of test steel is up to 485 MPa, while as using original process (/% : 0. 22C, 0. 43Si, 1. 37Mn and going to cold bed temperature at 690 ~ 730 X.) the average yield strength R_el is only 435 MPa.

摘要： HRB400钢（/%:0.21～0.25C,0.35～0.60Si,1.30～1. 55Mn,≤0.045P,≤0.045S）Φ14 mm钢材的生产工艺为100 t BOF-吹氩-150 mm×150 mm坯连铸-轧制。为解决因提高HRB400钢屈服强度并减少因C、Mn元素过高导致的钢材冷弯开裂现象,采用添加氮化钛合金进行Ti微合金化和优化控轧控冷的工艺试验。结果表明,当钢中Mn和Si含量（/%）分别降低0. 35和0. 10,添加0.007%Ti（试验2）或控制钢筋上冷床温度670～690℃,成品钢筋强度均能达到460 MPa的试验目标值;而在采用Ti微合金化和优化的冷却工艺（上冷床钢筋温度670～710℃,/%:0.22C, 0.34Si, 1.00Mn, 0.007Ti,试验3）试验钢的平均屈服强度R_el达到485 MPa,原工艺（上冷床温度690～730℃, /%:0. 22C,0. 43Si,1. 37Mn）的平均屈服强度R_el,仅为435 MPa。