Abstract:To reduce the production cost of billet on rebar production line, the rebar entering No.17 rolling mill is controlled at different temperatures by the pre-water-cooling device which is installed after No.16 rolling mill, and then the rebars of different temperatures are rolled through No.17 and No.18 rolling mills. The effects of steel billet rolling in different phase regions on its microstructure and properties were explored. The results show that when the steel grade HRB400-1NbS (w(Nb) is 0.025%) rebar is rolled in the austenite unrecrystallized zone (the temperature entering the No.17 rolling mill is (880±20) ℃), its yield strength is 437 MPa, and its tensile strength is 595 MPa. When the steel grade HRB400-0NbS (w(Nb) is 0.015%) rebar is rolled in the two-phase zone (the temperature entering the No.17 rolling mill is (780±20) ℃), its yield strength is 435 MPa, and its tensile strength is 605 MPa. The mechanical properties of the two are not much different, this is because when the HRB400-0NbS rebar is rolled in the two-phase zone, its grain size/grade is 10.5, which is smaller than the 9.5 of HRB400-1NbS rebar when it is rolled in austenite unrecrystallized zone. It compensates the second phase strengthening effect produced of Nb by fine-grain strengthening, which saves a cost of 40-50 yuan per ton for the billets of rebar production line.
蔡伟, 金梁, 毛俊春, 骆胜东, 陈龙, 王超. 不同相区轧制对螺纹钢组织和性能影响[J]. 中国冶金, 2021, 31(10): 75-80.
CAI Wei, JIN Liang, MAO Jun-chun, LUO Sheng-dong, CHEN Long, WANG Chao. Effect of different phase zones rolling on microstructures and properties of thread steels[J]. China Metallurgy, 2021, 31(10): 75-80.