Nb微合金化Q345qD钢的连续冷却转变行为  

Continuous Cooling Transformation Behavior of Nb Microalloyed Q345qD Steel

作　　者：黄家能 詹光曹 王义惠 许智平 周汝锦 朱丽娜 戴品强 Huang Jianeng;Zhan Guangcao;Wand Yihui;Xu Zhiping;Zhou Rujin;Zhu Lina;Dai Pinqiang(Fujian Sansteel Minguang Co.,Ltd.,Sanming 365000,Fujian;College of Materials Science and Engineering,Fujian University of Technology,Fuzhou 350118,Fujian;Fujian Key Laboratory of Advanced Materials Preparation and Forming Technology,Fuzhou 350118,Fujian;College of Materials Science and Engineering,Fuzhou University,Fuzhou 350118,Fujian)

机构地区：[1]福建三钢闽光股份有限公司,福建三明365000 [2]福建理工大学材料科学与工程学院,福建福州350118 [3]福建省新材料制备及成形技术重点实验室,福建福州350118 [4]福州大学材料科学与工程学院,福建福州350118

出　　处：《福建冶金》2024年第5期36-39,共4页Fujian Metallurgy

基　　金：福建省自然科学基金资助项目(项目编号:2021J05224)。

摘　　要：采用MMS-300热模拟试验机进行双道次热压缩试验,模拟了Nb微合金化Q345qD钢奥氏体的动态连续冷却转变过程。利用膨胀法结合金相检验和硬度测试,绘制了Nb微合金化Q345qD钢的动态连续冷却转变曲线。结果表明,当冷却速率在0.5℃/s~1℃/s时,Nb微合金化Q345qD钢的室温组织主要由多边形铁素体和珠光体组成;随着冷却速率增大至2℃/s时,室温组织中出现大量贝氏体;当冷却速率在5℃/s~20℃/s时,室温组织主要由铁素体和针状贝氏体组成。随着冷却速率从0.5℃/s增大至20℃/s,软相铁素体晶粒逐渐细化且含量逐渐减少,硬相贝氏体含量逐渐增多,Nb微合金化Q345qD钢的显微硬度从159.2 HV逐渐增大至271.8 HV。Dual pass hot compression deformation experiments were conducted on MMS-300 thermal simulation testing machine to simulate the dynamic continuous cooling transformation process of Nb microalloyed Q345qD steel.The dynamic continuous cooling transformation curve of Nb microalloyed Q345qD steel was plotted using the thermal expansion method combined with metallographic examination and hardness measurement.The results showed that when the cooling rate is 0.5℃/s~1℃/s,the room temperature microstructure of Nb microalloyed Q345qD steel is mainly composed of polygonal ferrite and pearlite.As the cooling rate increases to 2℃/s,a large amount of bainite appears in the room temperature microstructure.When the cooling rate is 5℃/s~20℃/s,the room temperature structure is mainly composed of ferrite and acicular bainite.With the increase of cooling rate from 0.5℃/s to 20℃/s,the ferrite grains refine gradually and its content decreases,while the content of bainite increases gradually,and the microhardness of Nb microalloyed Q345qD steel increases from 159.2 HV to 271.8 HV.

关 键 词：Q345qD钢 连续冷却转变 室温组织 显微硬度 

分 类 号：TG142.1[一般工业技术—材料科学与工程]