两相区退火对铁素体/贝氏体双相钢组织性能的影响

Effect of intercritical annealing on microstructure and properties of ferrite/bainite dual-phase steel

通过热模拟试验机、显微硬度计、电子万能拉伸试验机、光学显微镜和扫描电镜研究了不同两相区退火工艺对铁素体/贝氏体双相钢组织和力学性能的影响。结果表明,当采用传统的两相区退火工艺时,组织由铁素体、贝氏体和少量马氏体组成,且呈明显的带状。而淬火+两相区退火工艺可以细化组织,得到板条状的铁素体/贝氏体双相组织,并抑制马氏体组织的生成。此外,不同工艺两相区退火得到了体积分数相近的铁素体。与传统的两相区退火工艺相比,淬火+两相区退火工艺可以显著降低试验钢的屈强比并提高伸长率。

Effect of intercritical annealing process on microstructure and mechanical properties of ferrite/bainite dual-phase steel was studied by means of thermal simulation test machine,microhardness tester,electronic universal tensile testing machine,optical microscope and scanning electron microscope.The results show that under traditional intercritical annealing process,the microstructure is composed of ferrite,bainite and a small amount of martensite,and showing banded structures.The quenching+intercritical annealing process can refine the microstructure,obtain lath ferrite/bainite dual-phase structures,and inhibit the formation of martensite.Moreover,different processes obtain similar volume fractions of ferrite.Compared with the traditional intercritical annealing process,the quenching+intercritical annealing process can significantly reduce yield ratio and improve elongation of the tested steel.