ժҪ To study the microstructural evolution of pearlite steel subjected to pure rolling and rolling-sliding contact loading, a hypoeutectoid pearlite steel with composition and microstructure similar to BS11 was designed and twin-disc tests of this pearlite steel were performed to simulate the wheel/rail system. After a series of twin-disc tests, optical microscope (OM) observation, scanning electron microscope (SEM) observation, X-ray diffraction (XRD), and micro-hardness tests were conducted to characterize the microstructure. Under the pure rolling contact condition, a large amount of reticular cracks emerged within 60 ��m below the contact surface of the samples after 120000 revolutions. The largest deformation was approximately 200 ��m below the contact surface. Under the rolling-sliding contact condition, the nodularization of pearlite within 100 ��m below the contact surface was obvious. The microstructure and stress-strain distribution of the area within 2 mm below the contact surface were investigated. The distribution of micro-hardness under the contact surface varied with contact conditions. Finite element method (FEM) was used to simulate the stress-strain distribution. The results of SEM, FEM, and micro-hardness tests indicated that under the pure rolling contact condition, the maximum plastic strain was approximately 200-400 ��m below the contact surface. Conversely, under the rolling-sliding contact condition, the maximum plastic strain emerged on the contact surface. Under the pure rolling contact condition, the distribution of micro-hardness was almost identical to that of the equivalent plastic strain. Under the rolling-sliding contact condition, the distribution of micro-hardness was affected by the equivalent plastic strain and tangential stress.
Abstract��To study the microstructural evolution of pearlite steel subjected to pure rolling and rolling-sliding contact loading, a hypoeutectoid pearlite steel with composition and microstructure similar to BS11 was designed and twin-disc tests of this pearlite steel were performed to simulate the wheel/rail system. After a series of twin-disc tests, optical microscope (OM) observation, scanning electron microscope (SEM) observation, X-ray diffraction (XRD), and micro-hardness tests were conducted to characterize the microstructure. Under the pure rolling contact condition, a large amount of reticular cracks emerged within 60 ��m below the contact surface of the samples after 120000 revolutions. The largest deformation was approximately 200 ��m below the contact surface. Under the rolling-sliding contact condition, the nodularization of pearlite within 100 ��m below the contact surface was obvious. The microstructure and stress-strain distribution of the area within 2 mm below the contact surface were investigated. The distribution of micro-hardness under the contact surface varied with contact conditions. Finite element method (FEM) was used to simulate the stress-strain distribution. The results of SEM, FEM, and micro-hardness tests indicated that under the pure rolling contact condition, the maximum plastic strain was approximately 200-400 ��m below the contact surface. Conversely, under the rolling-sliding contact condition, the maximum plastic strain emerged on the contact surface. Under the pure rolling contact condition, the distribution of micro-hardness was almost identical to that of the equivalent plastic strain. Under the rolling-sliding contact condition, the distribution of micro-hardness was affected by the equivalent plastic strain and tangential stress.
��������:This work was financially supported by National Basic Research Programs of China;This work was financially supported by National Basic Research Programs of China
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E-mail: lqh13@mails.tsinghua.edu.cn
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Qiu-han LI,Chi ZHANG,Hu CHEN,Hao CHEN,Zhi-gang YANG. Microstructural Evolution of a Hypoeutectoid Pearlite Steel under Rolling-sliding Contact Loading[J]. �й������ڿ���, 2016, 23(10): 1054-1060.
Qiu-han LI,Chi ZHANG,Hu CHEN,Hao CHEN,Zhi-gang YANG. Microstructural Evolution of a Hypoeutectoid Pearlite Steel under Rolling-sliding Contact Loading. Chinese Journal of Iron and Steel, 2016, 23(10): 1054-1060.
2016, Vol. 23 
