低温贝氏体转变对渗碳纳米贝氏体轴承钢表层组织与性能的影响  

Effects of low temperature bainite transition on surface structure and properties of carburized nano-bainite bearing steel

作　　者：李伟[1] 秦羽满 王艳辉 康杰 杨志南 张福成[1,4] 尤蕾蕾 李艳国 LI Wei;QIN Yuman;WANG Yanhui;KANG Jie;YANG Zhinan;ZHANG Fucheng;YOU Leilei;LI Yanguo(State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao,Hebei 066004,China;College of Mechanical and Equipment Engineering,Hebei University of Engineering,Handan,Hebei 056038,China;School of Materials Science and Engineering,Hebei University of Science and Technology,Shijiazhuang,Hebei 050018,China;National Engineering Research Center for Equipment and Technology of Cold Strip Rolling,Yanshan University,Qinhuangdao,Hebei 066004,China;State Key Laboratory of Precision Bearings for Aviation,Luoyang LYC Bearing Co.Ltd.,Luoyang,Henan 471039,China)

机构地区：[1]燕山大学亚稳材料制备技术与科学国家重点实验室,河北秦皇岛066004 [2]河北工程大学机械与工程学院,河北邯郸056038 [3]河北科技大学材料科学与工程学院,河北石家庄050018 [4]燕山大学国家冷轧板带装备及工艺工程技术研究中心,河北秦皇岛066004 [5]洛阳LYC轴承有限公司航空精密轴承国家重点实验室,河南洛阳471039

出　　处：《燕山大学学报》2021年第1期25-32,共8页Journal of Yanshan University

基　　金：国家重点研究发计划项目(2017YFB0304501);国家自然科学基金资助项目(51871192,51831008);河北省自然科学基金资助项目(E2020203058);国家博士后科研基金资助项目(2018M631762);河北省高校青年人才项目资助项目(BJ2018056)。

摘　　要：本文设计了一种高碳钢,用于模拟轴承用渗碳纳米贝氏体钢表层的高碳层,并研究了随等温时间延长,其组织演变和力学性能变化规律。结果表明,当试验钢在200℃等温淬火时,贝氏体转变结束时间为48 h。随着等温时间的延长,马氏体含量降低,贝氏体铁素体含量升高,残余奥氏体含量先升高后降低,并在8 h时达到最高值,约为34.5%。贝氏体板条平均厚度约为69 nm。随等温时间的延长,试验钢的硬度先降低后升高,冲击韧性先升高后降低,且均在8 h等温时间条件下获得极值,硬度为最低值58.4HRC,冲击韧性为最高值101 J/cm^2。由于采用无缺口冲击试样,显著削弱了块状残余奥氏体对冲击韧性的消极影响,导致本文中冲击韧性与残余奥氏体含量呈现完全正相关的规律。In this paper,a high-carbon steel was designed to simulate the high-carbon layer on the surface of the carburized nanobainite steel for bearings.The evolution kinetics of the microstructure and mechanical properties of the high-carbon steel was studied as austempering time increases.Results indicated that the bainite transformation was nearly finished when the steel was austempered at 200℃for 48 h.With austempering time,the volume fraction of martensite decreased,while it increased for bainite ferrite.Yet,the volume fraction of retained austenite increased first and then decreased,with the maximum value of about 34.5%being obtained at 8 h.The mean thickness of bainite plates was about 69 nm.With austempering time,the hardness decreased first and then increased,while the impact toughness changed inversely.Both the hardness and impact toughness of the steel austempered for 8 h reached the extreme values,with the hardness of about 58.4 HRC and the impact toughness of about 101 J/cm^2.Due to the use of non-notched impact specimen,the negative impact of blocky retained austenite on impact toughness was weakened significantly,resulting in a completely positive correlation between the impact toughness and the volume fraction of retained austenite.

关 键 词：贝氏体轴承钢 纳米贝氏体 显微组织 机械性能 热处理 

分 类 号：TG142.1[金属学及工艺—金属材料]