摘要
采用激光熔覆技术在H13基体表面制备H13与Cr3C2-NiCr复合粉末的熔覆层,首先借助扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射(XRD)观察分析粉末和涂层的微观组织与相结构以及两者的结合特征,然后通过热震试验测试熔覆层的热疲劳性能,接着测试涂层表面和截面的显微硬度,最后使用高温摩擦磨损试验机测试各种因素对基体与熔覆层耐磨性的影响。结果表明,85%H13+15%NiCr-Cr3C2复合粉末的熔覆层质量最好,复合粉末主要由Fe-Ni相和Fe-Cr相组成,熔覆层主要物相为马氏体、Cr3C2、Cr7C3和(Cr·Fe)7C3。经过激光熔覆处理后,熔覆层的显微硬度随着Cr3C2-NiCr含量的增多而增大,熔覆层表面的显微硬度值接近1100 HV,熔覆层的平均显微硬度为920 HV。在相同条件下,基体的磨损深度显著大于熔覆层,表明熔覆层的耐磨性明显优于基体。
Objective With the development of science and technology and its needs in practical engineering,metal parts are often subjected to extreme conditions,such as high alternating stress,high temperature,high speed,and high corrosion.Therefore,solving the problem of repairing failed parts under extreme conditions is urgent and complicated.It is necessary to analyze and evaluate the failure mode and service life of parts and seek suitable repair materials and process methods.In this study,the hot working die of H13steel commonly used in engineering is taken as the background,and the strengthening and repair under extreme conditions are taken as the starting point,and investigates the laser cladding strengthening and remanufacturing technology to strengthen various parts suitable for operation under extreme conditions.Repair provides a certain reference significance.Recently,there have been successful study results based on laser cladding;however,the study on Cr3C2-NiCr powder as a laser cladding material is relatively rare.Therefore,Cr3C2-NiCr is selected herein as the cladding material where Cr3C2,as a reinforcing phase,can improve the wear resistance,heat resistance,and hardness of the mold surface.Its physical properties resemble those of H13steel,thereby reducing the melting cracking caused by material mismatch during the coating process.As an adhesive,NiCr can play a transitional role between the substrate and cladding material and improve the heat and corrosion resistance of the bonded part.Methods Laser cladding technology is used to prepare a cladding layer of H13and Cr3C2-NiCr composite powder on the surface of the H13substrate.The microstructure and phase structure of the cladding powder and coating and the bonding characteristics of the coating and substrate are observed and analyzed using scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and X-ray diffraction(XRD).The thermal fatigue property of the cladding layer is tested using a thermal shock test.The microhardness of the coating surf
作者
李洪波
高强强
李康英
李班
Li Hongbo;Gao Qiangqiang;Li Kangying;Li Ban(Key Laboratory of Advanced Forming Technology and Science of Ministry of Education,Yanshan University,Qinhuayigdao,Hebei 066004,China;College of Mechanical Engineering,Yanshan University,Qinhuangdao,Hebei 066004,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2021年第18期157-166,共10页
Chinese Journal of Lasers
基金
河北省高等学校科学技术研究项目(ZD2015089)。
关键词
激光技术
H13钢
激光熔覆
复合涂层
高温耐磨性
laser technique
H13 steel
laser cladding
composite coating
high temperature wear resistance
