Analysis of Intragranular Acicular Ferrite in Low Carbon Steels with Zr and Mg Co-additions

• 作 者: LiXiaobing;YuZhe;MinYi;LiuChengjun;JiangMaofa;
• 机 构: Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education),Northeaster
• 出 处: 第十届中国钢铁年会暨第六届宝钢学术年会
• 发表日期: 2015年期

　　The formation of intragranular acicular ferrite(IAF)was investigated by adding Zr and Mg simultaneously into Al–killed low carbon steel.Four steels containing various Mg and Zr were refined with vacuum induction furnace,and the characteristics of the inclusion and microstructure were studied scanning electron microscopy equipped with an energy–dispersive X–ray spectrometer.The formation of IAF is demonstrated to be enhanced by the additions of Mg and Zr in the steels,and the highest volume fraction of IAF is obtained in 0.0024%Mg-0.030%Zr steel.The nuclei inclusions are identified as Al2O3–MgO–MnS and Al2O3–MgO–ZrO2–(MnS)multiphase particles with size in the range of 1.5–3.0μm.Due to the number density of inclusions for 1.5–3.0μm is relatively low,thus the volume fraction of IAF is low as 18%even in 0.0024%Mg-0.030%Zr steel.Nevertheless,it is observed that the nucleation potential of inclusions is found to increase in the sequence of Al2O3–MgO and Al2O3–MgO–ZrO2.