奥氏体化时间与冷却速率对超高碳钢组织影响的EBSD研究
李俊杰，张成路，Andrew Godfrey*，刘 伟
(清华大学材料学院，先进材料教育部重点实验室，北京100084)
摘要：本文借助EBSD技术研究了一种超高碳钢在不同奥氏体化时间和冷却速率条件下原奥氏体晶粒和珠光体团簇尺寸的变化规律。实验结果表明：原奥氏体晶粒随奥氏体化时间延长而显著增大；与传统的热蚀法相比，EBSD重构法可以获得更加准确的原奥氏体晶粒尺寸。珠光体团簇尺寸随奥氏体化保温时间延长略微增大，随冷却速率减小而明显增大；与Channel 5自动截线法相比，手动截线法可获得更准确的团簇尺寸结果。
关键词：EBSD; 奥氏体化时间; 冷却速率; 原奥氏体晶粒; 珠光体团簇
中图分类号：TG142.1+1；TG115.21+5.3；TG115.23 文献标识码：A doi:10.3969/j.1000-6281.2013.06.001
EBSD investigation for influences of austenitization time and cooling rate on microstructure in a ultrahigh carbon steel
LI Jun-jie, ZHANG Cheng-lu, GODFREY Andrew*, LIU Wei
(Key Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084，China)
Abstract: Ultrahigh carbon steel becomes a growing scientific topic due to its potential for the application in a stronger cold drawn pearlitic steel wire. The prior austenite grain and nodule size are very important microstructure parameters for mechanical properties of pearlite steel. EBSD technique was employed to investigate the influences of austenitization time and cooling rate on the microstructure in a ultrahigh carbon steel. Experimental results show that the longer austenitization time at 1050 ℃increases the prior austenite grain size obviously and coarsening the pearlite nodule size slightly. The higher cooling rate decreases the pearlite nodule size dramatically. EBSD reconstruction method was compared with thermal etching method and found to be a better way for prior austenite grain size determination. For the pearlite nodule size measurement with EBSD, the manual intercept method can provide a reliable result than the Channel 5 automatic intercept method.
Keywords: EBSD; austenitization time; cooling rate; prior austenite grain; pearlite nodule
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[1] Li Y J, Choi P, Goto S, et al. Evolution of strength and microstructure during annealing of heavily cold-drawn 6.3 GPa hypereutectoid pearlitic steel wire[J]. Acta Materialia，2012, 60(9): 4005-4016.
[2] Taleff E M, Lewandowski J J, Pourladian B. Microstructure-property relationships in pearlitic eutectoid and hypereutectoid carbon steels[J]. Journal of the Minerals Metals & Materials Society，2002, 54(7): 25-30.
[3] Taleff E M, Syn C K, Lesuer D R, et al. Pearlite in ultrahigh carbon steels: Heat treatments and mechanical properties[J]. Metallurgical and Materials Transactions A，1996, 27(1): 111-118.
[4] Doi S N, Kestenbach H J. Determination of the pearlite nodule size in eutectoid steels[J]. Metallography，1989, 23(2): 135-146.
[5] Elwazri A M, Yue S. Effect of pearlite structure on the mechanical properties of microalloyed hypereutectoid steels[J]. Microalloying for New Steel Processes and Applications，2005, 500-501: 737-744.
[6] 李俊杰，Godfrey Andrew，刘伟. 奥氏体化与冷却速率对过共析钢组织的影响[J]. 金属学报，2013, 49(05): 583-592.
[7] Pous-Romero H, Lonardelli I, Cogswell D, et al. Austenite grain growth in a nuclear pressure vessel steel[J]. Metallurgical and Materials Transactions A，2013, 567: 72-79.
[8] 鲁法云，杨平，李萧，等. α-Ti晶粒尺寸的EBSD技术测定方法及分析[J]. 电子显微学报，2011，30(4-5): 388-393.
[9] 郭宁，黄天林，周正，等. EBSD技术结合背散射电子成像在材料研究中的应用[J]. 电子显微学报，2010，29（1）: 75-79.
[10] Morito S, Tanaka H, Konishi R, et al. The morphology and crystallography of lath martensite in Fe-C alloys[J]. Acta Materialia，2003, 51(6): 1789-1799.
[11] 李继康，李昭东. 超低碳马氏体的EBSD结构表征[J]. 电子显微学报，2011，30(4-5): 394-398.
[12] Abbasi M, Nelson T W, Sorensen C D, et al. An approach to prior austenite reconstruction[J]. Materials Characterization，2012, 66: 1-8.
[13] Walentek A, Seefeldt M, Verlinden B, et al. Electron backscatter diffraction on pearlite structures in steel[J]. Journal of Microscopy，2006, 224(3): 256-263.
[14] Elwazri A M, Wanjara P, Yue S. Effect of prior-austenite grain size and transformation temperature on nodule size of microalloyed hypereutectoid steels[J]. Metallurgical and Materials Transactions A，2005, 36A(9): 2297-2305.
