热处理及微合金化对珠光体轨钢疲劳寿命的影响  

Effect of heat treatment and microalloying on fatigue life of pearlitic rail steel

作　　者：刘畅 王东梅[1,2,3] 蒋宏利 刘东 岑耀东 包喜荣 陈林[1,2,3] Liu Chang;Wang Dongmei;Jiang Hongli;Liu Dong;Cen Yaodong;Bao Xirong;Chen Lin(School of Materials Science and Engineering,Inner Mongolia University of Science and Technology,Baotou Inner Mongolia 014010,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,Ministry of Education,Inner Mongolia University of Science and Technology,Baotou Inner Mongolia 014010,China;Bayuquan Steel Branch of Angang Co.,Ltd.,Yingkou Liaoning 115007,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]内蒙古科技大学轻稀土资源绿色提取与高效利用教育部重点实验室,内蒙古包头014010 [4]鞍钢股份有限公司鲅鱼圈钢铁分公司,辽宁营口115007

出　　处：《金属热处理》2025年第3期44-50,共7页Heat Treatment of Metals

基　　金：内蒙古自治区自然科学基金(2020BS05035);内蒙古科技大学创新基金(2019QDL-B04);内蒙古自治区直属高校基本科研业务费项目(2023QNJS036);内蒙古自治区科技重大专项(ZDZX2018024)。

摘　　要：为深入研究添加稀土元素和微合金元素以及热处理工艺对珠光体轨钢疲劳寿命的影响,对轧态和热处理态的BG400轨钢和对比设计的微合金化稀土试验钢进行了高周疲劳试验,并对疲劳断口进行了细致的观察分析。结果表明,900℃×15 min奥氏体化+540℃×60 s等温淬火的热处理工艺显著提高了轨钢的疲劳寿命,并且微合金化稀土试验钢的疲劳性能优于BG400钢,使得S-N曲线整体向右移动。这是因为合理的热处理工艺减小了珠光体的片层间距,稀土及微合金元素的加入有效地细化晶粒,两者共同作用使得裂纹在穿越不同取向的晶粒以及片层时需要消耗更多的能量,从而达到增强抵抗疲劳裂纹扩展的能力,减小疲劳辉纹间距并减缓疲劳裂纹扩展速率的效果,显著提高了钢的疲劳寿命。In order to further study the effects of adding rare earth and microalloying elements and heat treatment process on the fatigue life of the pearlitic rail steels,the high-cycle fatigue test was conducted on BG400 rail steel in rolled and heat-treated states and the contrast design of microalloyed rare earth tested steel,the fatigue fracture was also carefully observed and analyzed.The results show that the heat treatment process of austenitizing at 900℃for 15 min,followed by isothermal quenching at 540℃for 60 s,significantly improves the fatigue life of the rail steels,and the fatigue property of the microalloyed rare earth tested steel is better than that of BG400 steel,making the overall S-N curve move to the right.The reason is that rational heat treatment process reduces the lamellar spacing of pearlite.The addition of rare earth elements and microalloying elements effectively refines the grain size.The combining effect of these two factors means that cracks need to consume more energy when traversing grains of different orientations and lamellae.This enhances the ability to resist fatigue crack propagation,reduces the spacing of fatigue striations,and slows down the fatigue crack growth rate,thereby significantly improving the fatigue life of the steel.

关 键 词：热处理 稀土及微合金元素 疲劳寿命 断口分析 

分 类 号：TG111[金属学及工艺—物理冶金]