稀土La对高强IF钢中磷元素及含磷相析出的影响  

P Element and Precipitation P-Containing Precipitate in High Strength IF Steel with Rare Earth Lanthanum

作　　者：任东 金自力[1,2] 任慧平 李媛媛 李一鸣 张继舜[2] Ren Dong;Jin Zili;Ren Huiping;Li Yuanyuan;Li Yiming;Zhang Jishun(School of Material and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China;Key Laboratory of Advanced Metal Materials of Inner Mongolia,Baotou 014010,China;Shandong SteelGroup Rizhao City Co.,Lad.,Iron and Steel Research Institue,Rizhao 276800,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]山东钢铁集团日照有限公司钢铁研究院,山东日照276800 [3]内蒙古自治区新金属材料重点实验室,内蒙古包头014010

出　　处：《稀有金属》2021年第4期437-445,共9页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(50761005);内蒙古自治区科技重大专项项目(0902061701)资助。

摘　　要：采用有无稀土镧的440 MPa高强IF钢为研究对象,分别在两种钢铸坯凝固、热轧卷取、冷轧、退火过程中取样,研究稀土镧对P元素及含P析出相析出行为的影响。对两种钢退火后组织、力学性能、析出物种类进行观察与测定。电感耦合等离子体质谱仪(ICP-MS)测定两种钢不同状态下电解出的第二相中P元素浓度,并计算得析出P占成分中P的比值。使用透射电镜加能谱(TEM+EDS)确定含P析出相种类、形貌、数量及分布。结果表明:稀土镧使得高强IF钢组织细化,抗拉强度提高;高强IF钢在铸坯凝固、热轧卷取及退火过程中稀土镧均抑制P元素析出,使成品中P的固溶量增加约12%;Nb+Ti+P高强IF钢在热轧卷取和退火过程中析出的含P相均为Fe(Nb+Ti)P复合相。对两种试样冷轧及最终成品状态中Fe(Nb+Ti)P析出相面密度和平均尺寸进行统计,结果表明,两种状态下试样1的面密度差值大于试样2,并且两种状态下试样1中Fe(Nb+Ti)P析出相的平均尺寸差值小于试样2,说明稀土镧可以减少Fe(Nb+Ti)P相析出,同时可以促使Fe(Nb+Ti)P析出相长大。稀土镧对Fe(Nb+Ti)P相的析出方式无影响,即退火前期Fe(Nb+Ti)P尺寸小且多为点状和棒状,分布较分散,随退火时间延长新的Fe(Nb+Ti)P相在之前形成的较大Fe(Nb+Ti)P相上继续形核并析出,出现串状和树枝状等复杂形貌且分布逐渐团聚;稀土镧对Fe(Nb+Ti)P形成机制无影响,高强IF钢中首先形成FeTi与FeNb混合富集相,随着热轧和退火过程进行,钢中固溶的P元素不断析出并扩散进入优先形成的FeTi与FeNb混合相中形成Fe(Nb+Ti)P相。In recent years,more and more attention had been paid to the application value of rare earths in many industrial steel fields such as automobiles,military industry,and aerospace.This experiment mainly studied the role of rare earth elements in the production of high-strength IF steel.This experiment used 440 MPa high strength IF steel with or without lanthanum as the research object,the sample without lanthanum was Sample 1,and the sample with lanthanum was Sample 2.The samples were taken during solidification,hot rolling coiling,cold rolling and annealing of two kinds of steel,study on the effect of lanthanum on the precipitation behavior of P elements and P-containing precipitates.There were two annealing methods:continuous annealing and batch annealing.This experiment used batch annealing treatment,and the batch annealing process was carried out at 680℃,680℃for 2 h,kept at 680℃for 2 h and cooled down with furnace,and the samples were taken out by water cooling to room temperature.The microstructure,mechanical properties,types and morphology of precipitates of two kinds of steel after batch annealing were observed and measured.The microstructure was observed by metallographic microscope(OM),the mechanical properties were measured by tensile machine,and the precipitates were observed by transmission electron microscope(TEM).Determination of P element concentration in the second phase electrolyzed by two steels under different conditions by inductively coupled plasma mass spectrometry(ICP-MS),and the ratio of phosphorus in the sample to phosphorus in the component was calculated.Determination of the type,morphology,quantity and distribution of P-containing precipitates using TEM and energy dispersive spectrometer(EDS).The results showed that:rare earth lanthanum could refine the microstructure of high strength of steel and improve the yield strength and tensile strength of the final product.In the process of solidification,hot rolling coiling and annealing of high strength IF steel,rare earth lanthanum inhi

关 键 词：高强IF钢 稀土La 磷的析出与固溶 Fe(Nb+Ti)P 

分 类 号：TG142.1[一般工业技术—材料科学与工程]