中文摘要：

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%。

英文摘要：

Effects of cerium on structure and performance of IF steel were studied.Microstructures,inclusions and mechanical properties of the steel were characterized and analyzed with metallographic microscopy,scanning electron microscopy,energy disperse spectroscopy and universal tensile testing machine.The results show that trace cerium can distinctly improve microstructures of the steel,refine the grains and change polygonal aluminum oxide and-titanium nitride complex inclusions into axiolitic or globular rare earth-aluminum titanium inclusions.When the content of Ce is 0.0042%,the tensile strength,yield strength,elongation and Rockwell hardness increase by 44%,37%,13% and 59%,respectively.