不同等温温度对珠光体型高铁车轮钢组织及耐磨性的影响

Effect of different isothermal temperatures on microstructure and wear resistance of pearlitic wheel steel for high-speed railway

利用激光共聚焦显微镜和扫描电镜对一种珠光体型高铁车轮钢的组织和磨损形貌等进行了观察,研究了不同等温温度对其组织及耐磨性的影响。试验结果表明:在珠光体转变温度内对试验钢进行热处理得到了珠光体组织,随着等温温度的升高,珠光体片层间距增加,珠光体团尺寸减小,试验钢的显微硬度减小,珠光体钢的磨损量则增加。使用Si C粒度大的砂纸研磨后,珠光体钢的磨损量也增加了。珠光体钢的磨损表面呈现深浅程度不一的犁沟,磨损表面还存在一系列的剥离坑和细小的微裂纹,犁沟深度随着等温温度升高而逐渐增加。充分证明了珠光体片层间距越小的试验钢,其耐磨性能也越优异。

Effect of different isothermal temperatures on the microstructure and wear resistance of a pearlitic wheel steel for high-speed railway was studied,and the microstructure and wear morphologies were observed by laser confocal microscope and scanning electron microscope.The results show that the pearlite microstructure is obtained by heat treatment within the pearlite transition temperature range.As the isothermal temperature increases,the interlamellar spacing of pearlite increases,the pearlite colony size decreases,and the microhardness of the tested steel decreases,while the wear loss of the pearlitic steel increases.And after grinding by sandpaper with large Si C particles,the wear loss of the pearlitic steel also increases.The worn surface of the pearlitic steel shows ploughing of varying depth with a series of spalling pits and tiny micro-cracks on it,and the ploughing depth increases with the increase of isothermal temperature.It is proved that the smaller the lamellar spacing of pearlite is,the better the wear resistance of the tested steel is.