高级检索

    退火时间对C-Mn-Nb-Ti系深冲双相钢组织与性能的影响

    Effect of Annealing Time on Microstructure and Properties of C-Mn-Nb-Ti Deep-Drawing Dual Phase Steel

    • 摘要: 在860 ℃退火温度下对冷轧态C-Mn-Nb-Ti系深冲双相钢进行退火处理,研究了退火时间(180,240,300,360 s)对试验钢显微组织、织构特征、拉伸性能和成形性能的影响。结果表明:不同退火时间下试验钢的组织均为铁素体、马氏体和碳化物;随着退火时间的延长,马氏体含量增加,晶粒尺寸先减小后增大,当退火时间超过240 s后,铁素体晶粒粗化并呈现多边形化。试验钢主要由α织构和γ织构组成,随着退火时间的延长,111γ织构取向密度先升再降,试验钢的屈服强度和抗拉强度均增大,断后伸长率先基本不变后显著降低,塑性应变比和加工硬化指数先增大后减小,当退火时间为240 s时塑性应变比和加工硬化指数均达到最大值。860 ℃退火240 s后试验钢的综合力学性能和成形性能最佳,此时抗拉强度为526.1 MPa,屈服强度为351.7 MPa,断后伸长率为30.77%,塑性应变比为0.21,加工硬化指数为1.42。

       

      Abstract: The cold-rolled C-Mn-Nb-Ti deep-drawing dual phase steel was annealed at 860 °C. The effects of annealing time (180, 240, 300, 360 s) on the microstructure, texture characteristics, tensile properties and formability of the test steel were studied. The results show that the microstructure of the test steel was composed of ferrite, martensite and carbide under different annealing time periods. With the extension of annealing time, the content of martensite increased, and the grain size decreased first and then increased. When the annealing time exceeded 240 s, the ferrite grains were coarsened and showed polygonal shape. The test steel was mainly composed of α texture and γ texture. With the extension of annealing time, the orientation density of 111 γ texture increased first and then decreased, the yield strength and tensile strength of the test steel increased, the percentage elongation after fracture was basically unchanged first and then decreased significantly, and the plastic strain ratio and work hardening index increased first and then decreased. When the annealing time was 240 s, the plastic strain ratio and work hardening index reached the maximum values. After annealing at 860 °C for 240 s, the comprehensive mechanical properties and formability of the test steel were the best; the tensile strength was 526.1 MPa, the yield strength was 351.7 MPa, the percentage elongation after fracture was 30.77%, the plastic strain ratio was 0.21, and the work hardening index was 1.42.

       

    /

    返回文章
    返回