Nb-V复合微合金化对管线钢再加热奥氏体影响规律研究  

Research on the effect of Nb-V composite microalloying on austenite recrystallization of pipeline steel

作　　者：马启林 贾书君[2] 阴树标[1] 李拔[2] 刘清友[2] Ma Qilin;Jia Shujun;Yin Shubiao;Li Ba;Liu Qingyou(School of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,Yunnan,China;Engineering Steel Institute,Central Iron and Steel Research Institute,Beijing 100065,China)

机构地区：[1]昆明理工大学冶金与能源工程学院,云南昆明650093 [2]钢铁研究总院工程用钢所,北京100065

出　　处：《钢铁钒钛》2023年第1期158-166,共9页Iron Steel Vanadium Titanium

基　　金：国家重点研发计划项目(2018YFC0310302);河北省重点研发计划项目(19211007D)。

摘　　要：借助光学显微镜(OM)、高分辨透射电镜(HRTEM)等分析手段,通过热处理试验,热力学模型计算及therme-cacl软件分析等,研究了再加热过程中管线钢奥氏体晶粒尺寸和微合金元素溶解和析出行为之间的耦合关系。结果表明,试验钢在再加热温度1180℃、保温1.5 h时,此时奥氏体晶粒尺寸存在以下规律:Nb钢(61.14μm±5.59μm)<Nb-V钢(63.84μm±5.52μm)<V钢(71.89μm±6.8μm),此时Nb钢奥氏体中Nb元素的固溶量为0.064%,而Nb-V试验钢的固溶量为0.05%,此时两种试验钢在奥氏体中固溶的Nb含量差仅有0.014个百分点。通过建立热力学模型计算发现,在1050~1250℃温度区间内奥氏体晶粒长大激活能关系为Q_(Nb钢)>Q_(Nb-V钢)>Q_(V钢),进一步证实在该阶段奥氏体晶粒的长大主要与Nb元素固溶量成正相关。在再加热温度1180℃、保温1.5 h下Nb-V试验钢和Nb钢原奥氏体晶粒尺寸、Nb固溶量都在相近的范围内,从再加热阶段进一步验证了含V管线钢的可行性。Through heat treatment test,microstructure observation,thermodynamic model calculation and thermo-cacl software,the austenite grain size as well asthe dissolution and precipitation behavior of microalloying elements in pipeline steel during reheating had been investigated..The results show tha when the test steel is reheated at 1 180℃ and held for 1.5 hours,the austenite grain size order is as follows:Nb steel (61.14μm±5.59μm)QNb-V steel>QV steel,which further confirms that the growth of austenite grains at this stage is mainly positively correlated with the solid solution amount of Nb element.Under investigated reheating condition,the prior austenite grain size and solid solution Nb content in Nb-V test steel is similar to that of Nb steel,which confirms the feasibility of Nb-V microalloying pipeline steel from the prospective of reheating stage.

关 键 词：管线钢 Nb-V复合微合金化 奥氏体晶粒尺寸 第二相析出 激活能 

分 类 号：TF704.2[冶金工程—钢铁冶金] TG156[金属学及工艺—热处理]