Taking ZrC particles with the diameter of 0.2-1.0 μm as the enhancement, the tested steel containing ZrC particles were fabricated by presses casting method. The influence of addition of ZrC particles on microstructure and mechanical properties of the tested steel were investigated by the thermal simulation experiment, mechanical properties test and TEM so on. The results show that ZrC particles are distributed evenly in the substrate 20Mn2 steels and refine substrate crystal grain. In the rolling process, ZrC particles can accelerate the process of deformation induced ferrite transformation, thus increasing the nucleation rate of ferrite, resulting in ultrafine grain. The fine microstructure with a grain size of 3.9 μm is obtained for the plate with the thickness of 9 mm fabricated using the tested steel containing 0.5% (volume fraction) ZrC particles with the diameter of 0.4 μm. The yield strength of the steel increases by 58% compared with that of commercial steel 20Mn2. All of these are mainly attributed to the effects of good fine crystal strengthening and second strengthens of micron ZrC particles.%以粒径为0.2～1.0μm的ZrC颗粒为增强相,采用压入铸造法制备含ZrC粒子的试验钢,通过热模拟实验、性能测试、透射电镜等方法,研究ZrC粒子对钢的组织细化和力学性能的影响.研究结果表明:ZrC粒子在基体20Mn2钢中分布均匀,能细化基体晶粒;在轧制过程中,ZrC粒子能加速形变诱导铁素体相变的进程,导致组织超细化;当ZrC粒子的平均粒径为0.4μm、加入量(体积分数)为0.5％时,实验室轧后水冷可获得晶粒粒径为3.9μm的9mm中板,材料的屈服强度提高58％,综合性能显著提高,这主要归因于微米ZrC增强相良好的细晶强化及第二相强化作用.
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