采用向IF钢中添加微量Ce元素的方法,研究不同Ce含量对IF钢组织和性能的影响。借助于金相显微镜、扫描电镜、能谱仪和万能拉伸试验机等检测手段,对添加Ce的IF钢的显微组织、夹杂物和力学性能进行了表征和分析。结果表明,IF钢中加入微量Ce可明显改善钢的显微组织,晶粒得到细化,且随着Ce含量的增加,分布更加均匀;同时钢中夹杂物得到变性,由原来多边形的Al2O3和TiN复合夹杂转变为椭球状或球状的含Al、Ti的稀土复合夹杂。钢中Ce含量达到0.0042%时,其抗拉强度、屈服强度、延伸率及洛氏硬度比未加Ce的IF钢分别提高了44%、37%、13%和59%。 The effect of different Ce content on the microstructure and properties of IF steel was studied by adding Ce to IF steel. The microstructure, inclusions and mechanical properties of Ce-added IF steel were characterized and analyzed with the help of the means of metallographic microscope, scanning electron microscopy, energy dispersive spectrometer and universal tensile testing machine. The results show that adding a small amount of Ce into IF steel can obviously improve the microstructure of the steel, the grains are refined, and the distribution becomes more uniform with the increase of the Ce content. Meanwhile, the inclusions in the steel are denatured, TiN composite inclusions into ellipsoidal or spherical Al, Ti rare earth composite inclusions. The tensile strength, yield strength, elongation and Rockwell hardness of the steels with Ce content up to 0.0042% were 44%, 37%, 13% and 59% higher than those of the steels without Ce respectively.