摘要
选用钴基合金粉末和铁基合金粉末,利用CO 2多模激光器对轮轨材料进行激光熔覆处理.分析了钴基合金涂层和铁基合金涂层的微观组织、成分、硬度与应力状态.未处理试样表面残余应力为拉应力,激光熔覆处理后,涂层表面残余应力为压应力.利用MJP-30A滚动接触疲劳试验机对激光熔覆处理前后轮轨试样进行滚动摩擦磨损试验.结果表明:激光熔覆处理后轮轨试样磨损率明显降低,其中激光熔覆钴基合金后,轮轨试样磨损率分别降低96.7%和98.9%,激光熔覆铁基合金后,轮轨试样磨损率分别降低81.7%和93.5%.未处理轮轨试样表面损伤为疲劳损伤;钴基合金涂层表面损伤最轻微,磨痕表面光滑,出现轻微的小块剥落;铁基合金涂层表面出现细小裂纹和犁沟.
Co-based alloy powders and Fe-based alloy powders were chosen to perform laser cladding on the wheel/rail materials through a CO2 multimode laser. The microstructures, compositions, hardness and stress states of the Co-based alloy and Fe-based alloy cladding layers were analyzed. The residual stress on the surface of untreated specimen was tensile stress, and the residual stresses on surfaces of the laser cladding coatings were compressive stress. The rolling friction and wear tests were carried out with the untreated and laser treated wheel/rail specimens on the MJP-30A rolling contact fatigue testing machine. The results showed that the wear rates of wheel/rail specimens were obviously reduced after laser cladding. The wear rates of wheel and rail specimens with Co-based alloy coating were decreased by 96.7%and 98.9%, respectively, and the wear rates of wheel and rail specimens with Fe-based alloy coating were decreased by 81.7% and 93.5%, respectively. The untreated wheel/rail specimens showed fatigue damage. The Co-based alloy coating was damaged the most slightly, the worn surface was smooth with slight flaking. The Fe-based alloy coating showed tiny cracks and furrows.
作者
慕鑫鹏
王文健
祝毅
沈明学
刘启跃
郭俊
丁昊昊
MU Xinpeng;WANG Wenjian;ZHU Yi;SHEN Mingxue;LIU Qiyue;GUO Jun;DING Haohao(Tribology Research Institute,State Key Laboratory of Traction Power,Southwest Jiaotong University,Sichuan Chengdu 610031,China;State Key Laboratory of Fluid Power and Mechatronic Systems,Zhejiang University,Zhejiang Hangzhou 310027,China;School of Materials Science and Engineering,East China Jiaotong University,Jiangxi Nanchang 330013,China)
出处
《摩擦学学报》
EI
CAS
CSCD
北大核心
2020年第2期225-233,共9页
Tribology
基金
四川省重点研发计划项目(2019YFG0289)
国家重点研发计划(2016YFB1102601)
国家自然科学基金(51775455)资助.
关键词
激光熔覆
轮轨材料
磨损
损伤
残余应力
laser cladding
wheel/rail materials
wear
damage
residual stress
