回火对含稀土空冷贝氏体油套管用钢组织与性能的影响  

Effect of tempering on microstructure and properties of air cooled bainite steel containing rare earth for oil casing

作　　者：韩强 高智敏[1] 贾欣 李涛 孙昭琦[1] 代从伟 Han Qiang;Gao Zhimin;Jia Xin;Li Tao;Sun Zhaoqi;Dai Congwei(School of Materials Science and Engineering,Inner Mongolia University of Science and Technology,Baotou Inner Mongolia O14010,China;Inner Mongolia Key Laboratory of New Metal Material,Baotou Inner Mongolia 014010,China;Key Laboratory of Green Extraction&Efficient Utilization of Light Rare-Earth Resources(Inner Mongolia University of Science and Technology),Ministry of Education,Baotou Inner Mongolia 014010,China;Equipment Engineering Department of Baotou Iron and Steel Group Corporation,Baotou Inner Mongolia 014010,China)

机构地区：[1]内蒙古科技大学材料科学与工程学院,内蒙古包头014010 [2]内蒙古自治区新金属材料重点实验室,内蒙古包头014010 [3]轻稀土资源绿色提取与高效利用教育部重点实验室(内蒙古科技大学),内蒙古包头014010 [4]包钢集团公司包钢股份设备工程部,内蒙古包头014010

出　　处：《金属热处理》2025年第1期180-186,共7页Heat Treatment of Metals

基　　金：内蒙古自治区科技计划(2020GG0207);内蒙古自然科学基金(2021LHMS05028)。

摘　　要：对比研究了添加稀土Ce和不同回火工艺对空冷贝氏体油井管钢的显微组织、第二相析出行为及硬度的影响,采用热膨胀仪对稀土和非稀土贝氏体钢的相变点进行了测定,使用金相显微镜和透射电镜对回火后的微观组织和第二相进行观察分析,使用热力学计算软件对第二相析出行为进行模拟计算,采用洛氏硬度计对试验钢回火后的硬度进行测试。结果表明,经200、450和650℃回火不同时间后,非稀土贝氏体钢的组织分别为回火马氏体、回火屈氏体和回火索氏体,稀土贝氏体钢的组织分别为回火马氏体、回火屈氏体、回火屈氏体+回火索氏体。650℃回火60 min时,贝氏体钢中的第二相为(Fe,Cr)_(3)C和Cr_(23)C_(6)型碳化物。随回火温度的升高和回火时间的延长,稀土和非稀土贝氏体钢的硬度总体呈下降趋势,在450℃回火120 min时发现二次硬化现象,且稀土贝氏体钢的硬度高于非稀土贝氏体钢。稀土Ce的加入对贝氏体钢具有提高相变点温度,推迟珠光体转变,提高硬度的作用。Effects of addition of rare earth Ce and tempering process on microstructure,precipitation behavior of the second phase and hardness of air-cooled bainite steel for oil casing were compared and studied.The phase transition points of the rare earth and non-rare earth bainite steels were determined by thermal dilatometer,the microstructure and the second phase after tempering were observed and analyzed by using metallographic microscope and TEM,the precipitation behavior of the second phase was simulated by thermodynamic calculation software,and the hardness of the tested steels was tested by using Rockwell hardness tester.The results show that after tempering at 200,450 and 650 ℃,respectively,for different time,the microstructure of the non-rare earth bainite steel is tempered martensite,tempered troostite and tempered sorbite,respectively,however,the microstructure of the rare earth bainite steel is tempered martensite,tempered troostite and tempered troostite+tempered sorbite,respectively.When tempered at 650 ℃ for 60 min,the second phases in the bainite steels are(Fe,Cr)_(3C) and Cr_(23)C_(6) carbides.With the increase of tempering temperature and time,the hardness of the rare earth and non-rare earth bainite steel decreases overall,while the secondary hardening phenomenon is found when tempered at 450 ℃ for 120 min,and the hardness of the rare earth bainite steel is higher than that of the non-rare earth bainite steel.In conclusion,the addition of rare earth Ce can increase the temperature of the phase transition point,delay the pearlite transformation and improve the hardness of bainite steel.

关 键 词：空冷贝氏体钢 回火工艺 油套管 组织性能 稀土 

分 类 号：TG156.5[金属学及工艺—热处理]