感应回火对含钒900 MPa级高强钢组织与性能的影响

    Effects of Induction Tempering on Microstructure and Properties of 900 MPa Grade High Strength Steel Containing Vanadium

    • 摘要: 对含钒Q960E 高强钢进行热轧和900 ℃淬火,并对其分别在450、550 和600 ℃下进行感应回火处理。通过扫描电子显微镜(SEM)与投射电子显微镜(TEM) 研究了Q960E 高强钢不同感应回火温度下的组织特征。结果表明:淬火后Q960E 钢板组织由马氏体+贝氏体复相组织组成,并通过提高终轧和卷曲温度保证了感应回火前的板形质量。高温回火后组织为回火索氏体。通过V 的添加,在感应回火过程中均匀弥散析出尺寸小于100 nm 的析出相,保证了感应高温回火后的板材强度,并随回火温度的升高,部分回火马氏体消失,形成回火索氏体组织。在900 ℃/15 min 淬火,(550~600 ℃)/15 min 高频感应回火可以获得Q960E 的最佳力学性能,通卷横向强度波动小于10 MPa,通卷纵向强度波动范围小于30 MPa,通卷横、纵向伸长率稳定在12%以上。

       

      Abstract: The high strength steel containing vanadium Q960E was hot-rolled and quenched at 900℃, and it was subjected to induction tempering at 450, 550 and 600 ℃, respectively.By means of scanning electron microscope (SEM) and projection electron microscope (TEM), the microstructure characteristics of Q960E steel at different temperature of induction tempering were studied. The results show that the microstructure of Q960E steel plate after quenching is martensite+bainite complex structure, and the shape quality before induction tempering is ensured by increasing the final rolling and crimping temperature. After high temperature tempering, the microstructure is tempered sorbite. By the addition of V, the precipitate phase of < 100 nm is uniformly dispersed during the induction tempering process. The plate strength after induction high temperature tempering is guaranteed. And with the increase of tempering temperature, the partial tempering martensite disappears and the tempering sorbite structure is formed. The best mechanical properties of Q960E can be obtained by high frequency induction tempering at 900 ℃/15 min, (550-600 ℃) /15 min, the transverse strength fluctuation of the pass coil is< 10 MPa, and the longitudinal strength fluctuation range of the pass coil is < 30 MPa. Transverse and longitudinal elongation are stable at more than 12%.

       

    /

    返回文章
    返回