铌钒微合金化HRB500E钢筋轧制工艺研究

Research on rolling process of Nb-V microalloying HRB500E steel bar

使用Gleeble 3800热模拟仪研究铌钒微合金化HRB500E钢筋的连续冷却相变行为,并在不同加热温度下进行生产试制。热模拟试验结果显示,钢筋加热至1 200℃,在1 050℃变形,冷却速率为0.8℃/s的工艺下,铁素体体积分数为43.7%,铁素体晶粒尺寸为10.8μm,珠光体体积分数为56.3%,珠光体团尺寸为22.4μm。实际生产中,加热至1 200℃,在1 000℃上冷床空冷,HRB500E钢筋显微组织由铁素体和珠光体组成,屈服强度大于500 MPa,抗拉强度大于650 MPa,强屈比大于1.25,断后伸长率大于16.0%,最大力总延伸率大于9.0%,符合国家标准要求。

Gleeble 3800 thermal simulator was used to study continuous cooling phase transformation behavior of Nb-V microalloyed HRB500E steel bars,and production prototype was carried out at different heating temperatures.The results of thermal simulation test show that ferrite volume fraction is 43.7%,ferrite grain size is 10.8μm,pearlite volume fraction is 56.3%,and pearlite cluster size is 22.4μm under process of heating to 1200℃,deformation at 1050℃,and cooling rate 0.8℃/s.In actual production,heated to 1200℃,cooled on 1000℃and air-cooled,microstructure of HRB500E steel bar is composed of ferrite and pearlite,yield strength is more than 500 MPa,tensile strength is more than 650 MPa,strong yield ratio is more than 1.25,elongation after fracture is more than 16.0%,and maximum total force elongation is more than 9.0%,which meets requirements of national standard.