氮碳共渗45钢的滚动接触疲劳失效机理  

Rolling contact fatigue mechanism of nitrocarburized 45 steel

作　　者：王军威[1,2] 李国禄[1] 王海斗[2] 徐滨士[2] 康嘉杰[2] 

机构地区：[1]河北工业大学材料科学与工程学院,天津300130 [2]装甲兵工程学院装备再制造技术国防科技重点实验室,北京100072

出　　处：《材料热处理学报》2012年第10期124-129,共6页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金面上项目(50975285);国家自然科学基金重点项目(50735006);国家"973"计划(2011CB013405)

摘　　要：利用盐浴氮碳共渗对45钢进行表面改性,采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)和光学显微镜(OM)等测试手段对改性层的显微结构和组织性能进行了表征。基于球盘式接触疲劳试验机研究了改性层在不同状态下的接触疲劳性能,并采用扫描电子显微镜(SEM)对失效形貌进行了分析。结果表明:45钢氮碳共渗改性层的疲劳裂纹萌生于表面和次表面,失效形式以剥落和表面磨损为主;疏松的白亮层降低了改性层的抗接触疲劳性能,扩散层上保留的5～8μm致密白亮层能有效提高改性层的抗接触疲劳性能。Modified layer was prepared on surface of a 45 steel by nitroearburizing in salt bath. The microstructure of the modified layer were investigated by means of scanning electric microscopy （ SEM ） , X-ray diffraction （XRD） and optical microscope （ OM ）. Contact fatigue property of the modified layer in different conditions were researched on a ball-on-disk tester and the failure mechanism was discussed. The results indicate that the failures initiated at surface and sub-surface,and the failure modes of the nitroearburized steel are mainly spalling off abrasion. The compound layer with typical porous structure can reduce the anti-fatigue property of the modified layer, however,removing the porous compound layer and reserving the dense compound layer of 5 -8 μm above the diffusion layer, the anti- fatigue property of the modified layer is increased significantly.

关 键 词：氮碳共渗 45钢 滚动接触疲劳 硬度 失效机理 

分 类 号：TG174.4[金属学及工艺—金属表面处理]