外加微米ZrC颗粒对低碳微合金钢组织及性能的影响

Effects of Additional Micron Grade ZrC Particles on Microstructure and Performance of a Low-carbon Microalloy Steel

本文研究了ZrC颗粒加入量对低碳微合金钢组织和力学性能的影响。对试验钢进行了各种力学性能的测试,并用金相显微镜和TEM观察了试验钢的微观组织,用SEM观察了ZrC颗粒的分布状态及拉伸断口形貌。结果表明,加入ZrC颗粒后,试验钢的晶粒都得到了一定程度的细化,当加入ZrC颗粒体积含量为1.1%时,晶粒被细化到5.5μm,此时试验钢的抗拉强度、屈服强度、伸长率、冲击韧性和维氏硬度分别达到635MPa、517.5MPa、20.66%、215.0J/cm2和214 Hv5,获得了最佳综合力学性能;添加ZrC颗粒后,试验钢的组织仍为铁素体,拉伸断口仍为韧窝状;轧制态试验钢中ZrC颗粒分布较为均匀。

Effects of the content of micron grade ZrC particles on the microstructure and mechanical properties of a low-carbon microalloy steel were investigated.The mechanical properties of the test steels were determined by tensile test,impact test and hardness test.The microstructures of the test steels were observed by metallographic microscopy and transmission electron microscopy（TEM）.The distribution of ZrC particles and the tensile fractography were observed by scanning electron microscopy（SEM）.The results show that the grains of the test steels are all refined to some extent by adding ZrC particles.The grains are refined to 5.5μm and the optimum integrating mechanical properties can be obtained when the volume content of ZrC particles is 1.1%.The tensile strength,yield strength,extensibility,impact toughness and HV hardness of the steel were 635MPa,517.5MPa,20.66%,215.0J/cm^2 and 214 Hv5,respectively.The microstructures are all still ferrites,and the tensile fractures are all still dimples for the test steels with additional ZrC particles.The distribution of ZrC particles in the rolled test steels is relatively homogeneous.