钢中珠光体球团尺寸的EBSD表征技术
|
摘要
借助光学显微镜和扫描电镜等研究了珠光体球团的表征方法,从阻止裂纹扩展的有效性出发,选择内部取向接近、外部取向差较大的球团簇作为评价珠光体球团尺寸的指标。结果表明,珠光体中铁素体的取向分布与球团吻合,即铁素体的大角度晶界就是球团(簇)界,所以可以通过表征铁素体的晶粒尺寸来评价珠光体球团尺寸。该方法的关键点在于晶界如何定义和样品如何制备。从对EBSD法的可行性分析可知,以15°作为晶内最大取向差来划分珠光体球团。对于珠光体钢,电解抛光法更适用于珠光体中渗碳体片层较宽的样品,而对于珠光体中渗碳体片层过窄的情况更适合选用离子抛光法。
The method of characterization of pearlite nodule was studied and discussed by means of EBSD,optical metallography and scanning electron microscopy( SEM). From the view of preventing the crack propagation,the nodules with similar internal orientation and large external orientation difference were selected as an indicator of pearlite nodule size evaluation. The results show that the orientation distribution of ferrite in pearlite coincides with that of the nodule,that is,the large angle grain boundary of ferrite coincides with the nodule boundary,so the pearlite nodule size can be evaluated by characterizing the grain size of ferrite. The key point of this method is how to define the grain boundary and how to prepare the sample. From the feasibility analysis of the EBSD method,it is known that the pearlite nodules are divided by 15° as the maximum orientation difference. For pearlitic steel,the electropolishing method is more suitable for a sample with a wider cementite layer in the pearlite,and the ion polishing method is more suitable for the case where the cementite layer in the pearlite is too narrow.
The method of characterization of pearlite nodule was studied and discussed by means of EBSD,optical metallography and scanning electron microscopy( SEM). From the view of preventing the crack propagation,the nodules with similar internal orientation and large external orientation difference were selected as an indicator of pearlite nodule size evaluation. The results show that the orientation distribution of ferrite in pearlite coincides with that of the nodule,that is,the large angle grain boundary of ferrite coincides with the nodule boundary,so the pearlite nodule size can be evaluated by characterizing the grain size of ferrite. The key point of this method is how to define the grain boundary and how to prepare the sample. From the feasibility analysis of the EBSD method,it is known that the pearlite nodules are divided by 15° as the maximum orientation difference. For pearlitic steel,the electropolishing method is more suitable for a sample with a wider cementite layer in the pearlite,and the ion polishing method is more suitable for the case where the cementite layer in the pearlite is too narrow.
引文
[1]栾佰峰,张达,郭宁,等.桥梁缆索用过共析钢热轧盘条微观组织定量表征[J].材料热处理学报,2011,32(7):78-82.Luan Baifeng,Zhang Da,Guo Ning,et al.Quantitative characterization on the microstructure of hotrolled hypereutectoid steel wire rod for bridge cable[J].Journal of Materials Heat Treatment,2011,32(7):78-82.
[2]Elwazri A M,Wanjara P,Yue S.Measurement of pearlite interlamellar spacing in hypereutectoid steels[J].Materials Characterization,2005,54(4):473-478.
[3]Hu X,Houtte V P,Liebeherr M,et al.Modeling work hardening of pearlitic steels by phenomenological and Taylor-type micromechanical models[J].Acta Materialia,2006,54(4):1029-1040.
[4]Elwazri A M,Wanjara P,Yue S.The effect of microstructural characteristics of pearlite on the mechanical properties of hypereutectoid steel[J].Materials Science and Engineering A,2005,404(1):91-98.
[5]Lewandowski J J,Thompson A W.Micromechanisms of cleavage fracture in fully pearlitic microstructures[J].Acta Metallurgica,1987,35(7):1453-1462.
[6]Fernández A,Carsi M,Penalba F,et al.Toughness dependence on the microstructural parameters for an ultrahigh carbon steel(1.3wt%C)[J].Materials Science and Engineering A,2002,335(1):175-185.
[7]马跃,彭云,苏航.高速车轮钢韧化机理及工艺优化研究[D].北京:钢铁研究总院,2012.Ma Yue,Peng Yun,Su Hang.Study on toughening mechanism andproduction process optimization of wheel steel for high speed train[D].Beijing:Iron and Steel Research Institute,2012.
[8]Furuhara T,Moritani T,Sakamoto K,et al.Substructure and crystallography of degenerate pearlite in an Fe-C binary alloy[J].Materials Science Forum,2007,539-543:4832-4837.
[9]Park Y J,Bernstein I M.The process of crack initiation and effective grain size for cleavage fracture in pearlitic eutectoid steels[J].Metallurgical Transactions A,1979,10(11):1653-1664.
[10]Doi S N,Kestenbach H J.Determination of the pearlite nodule size in eutectoid steels[J].Metallography,1989,23(2):135-146.
[11]Pickering F B,Garbaz B.The effect of transformation temperature and prior austenite grain size on the pearlite colony size in vanadium treated pearlitic steels[J].Scripta Metallurgic,1987,21(3):249-253.
[12]马跃,彭云,潘涛,等.中高碳钢珠光体球团尺寸的快速精确统计方法[J].材料热处理学报,2012,33(6):64-69.Ma Yue,Peng Yun,Pan Tao,et al.Fast and precise determination of pearlite colony size in medium-high carbon steels[J].Transactions of Materials and Heat Treatment,2012,33(6):64-69.
[13]Walentek A,Seefeldt M,Verlinden B,et al.Investigation of pearlite structure by means of electron backscatter diffraction and image analysis of SEM micrographs with an application of the Hough transform[J].Materials Science and Engineering A,2008,483(1):716-718.
[14]Tetsuya T,Dirk P,Dierk R.Investigation of orientation gradients in pearlite in hypoeutectoid steel by use of orientation imaging microscopy steel[J].Research International,2007,78(1):38-44.
[2]Elwazri A M,Wanjara P,Yue S.Measurement of pearlite interlamellar spacing in hypereutectoid steels[J].Materials Characterization,2005,54(4):473-478.
[3]Hu X,Houtte V P,Liebeherr M,et al.Modeling work hardening of pearlitic steels by phenomenological and Taylor-type micromechanical models[J].Acta Materialia,2006,54(4):1029-1040.
[4]Elwazri A M,Wanjara P,Yue S.The effect of microstructural characteristics of pearlite on the mechanical properties of hypereutectoid steel[J].Materials Science and Engineering A,2005,404(1):91-98.
[5]Lewandowski J J,Thompson A W.Micromechanisms of cleavage fracture in fully pearlitic microstructures[J].Acta Metallurgica,1987,35(7):1453-1462.
[6]Fernández A,Carsi M,Penalba F,et al.Toughness dependence on the microstructural parameters for an ultrahigh carbon steel(1.3wt%C)[J].Materials Science and Engineering A,2002,335(1):175-185.
[7]马跃,彭云,苏航.高速车轮钢韧化机理及工艺优化研究[D].北京:钢铁研究总院,2012.Ma Yue,Peng Yun,Su Hang.Study on toughening mechanism andproduction process optimization of wheel steel for high speed train[D].Beijing:Iron and Steel Research Institute,2012.
[8]Furuhara T,Moritani T,Sakamoto K,et al.Substructure and crystallography of degenerate pearlite in an Fe-C binary alloy[J].Materials Science Forum,2007,539-543:4832-4837.
[9]Park Y J,Bernstein I M.The process of crack initiation and effective grain size for cleavage fracture in pearlitic eutectoid steels[J].Metallurgical Transactions A,1979,10(11):1653-1664.
[10]Doi S N,Kestenbach H J.Determination of the pearlite nodule size in eutectoid steels[J].Metallography,1989,23(2):135-146.
[11]Pickering F B,Garbaz B.The effect of transformation temperature and prior austenite grain size on the pearlite colony size in vanadium treated pearlitic steels[J].Scripta Metallurgic,1987,21(3):249-253.
[12]马跃,彭云,潘涛,等.中高碳钢珠光体球团尺寸的快速精确统计方法[J].材料热处理学报,2012,33(6):64-69.Ma Yue,Peng Yun,Pan Tao,et al.Fast and precise determination of pearlite colony size in medium-high carbon steels[J].Transactions of Materials and Heat Treatment,2012,33(6):64-69.
[13]Walentek A,Seefeldt M,Verlinden B,et al.Investigation of pearlite structure by means of electron backscatter diffraction and image analysis of SEM micrographs with an application of the Hough transform[J].Materials Science and Engineering A,2008,483(1):716-718.
[14]Tetsuya T,Dirk P,Dierk R.Investigation of orientation gradients in pearlite in hypoeutectoid steel by use of orientation imaging microscopy steel[J].Research International,2007,78(1):38-44.