退火工艺对低碳贝氏体钢组织与力学性能的影响

Effect of annealing process on microstructure and mechanical properties of low carbon bainitic steel

以双辊铸轧工艺生产的低碳贝氏体钢为研究对象,研究了退火工艺对其组织与力学性能的影响。结果表明,试验钢的组织为粒状贝氏体,退火后该组织会逐渐发生分解。在500℃进行长时间保温退火时,随着保温时间的增加,屈服强度和抗拉强度逐渐上升,伸长率变化不大。退火后试验钢强度的增加是由Nb析出强化引起的。当保温时间为3 min、退火温度650℃时,试样的屈服强度和抗拉强度达到最大值。

Effect of annealing process on microstructure and mechanical properties of a low carbon bainitic steel produced by twin-roll casting and rolling process was studied.The results show that microstructure of the tested steel is granular bainite,which is gradually decomposed after annealing.As the increase of soaking time,the yield strength and tensile strength increase gradually when annealed at 500℃ for long time,and the elongation does not change much.After annealing,the increase of strength is caused by NbC precipitation strengthening.The yield strength and tensile strength of the steel reach the maximum when annealed at 650℃ for 3 min.