摘要
采用爆炸喷涂方法在2Cr10MoVNbN钢基体表面制备了Cr3C2-NiCr涂层,利用光学显微镜、扫描电镜、X射线衍射仪、能谱仪、显微硬度计、电子拉伸试验机、X射线应力仪、疲劳试验机等分析测试了涂层的缺陷、显微硬度、断裂韧度、结合力、残余应力、疲劳性能等,主要研究了涂层对基体疲劳性能的影响。结果表明:在2Cr10MoVNbN钢基体上采用爆炸喷涂方法制备的Cr3C2-NiCr涂层的孔隙率为0.5%,表面硬度为921 HV,断裂韧度为3.67 MPa.m1/2,涂层与基体的结合强度为63 MPa,涂层表面、涂层/基体界面处均处于压应力状态;爆炸喷涂Cr3C2-NiCr涂层明显降低了2Cr10MoVNbN钢基体的疲劳性能,在应力幅小于500 MPa时,与基体试样相比,涂层试样的疲劳寿命减少了75%以上,疲劳强度下降了134.7 MPa,涂层试样的疲劳裂纹源出现在涂层/基体界面的Al2O3夹杂物处。
Cr3C2-NiCr coating was deposited on 2Cr10MoVNbN steel substrate by detonation spraying method. The defect, micro-hardness, fracture toughness, adhesion to the substrate and residual stress for as- sprayed coating were respectively investigated by means of optical microscopy（OM）, scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy dispersive spectrometer（EDS）, micro-hardness tester, electronic tensile testing machine and X-ray strain apparatus. The effect of Cr3C2-NiCr coating on fatigue property of 2Cr10MoVNbN steel was studied. The results show that the porosity of the coating was 0. 5%, the surficial hardness was 921 HV, the fracture toughness was 3.67 MPa·m^1/2, and the adhesion to substrate was 63 MPa. Both surface and coating- substrate interface showed compressive residual stress. The Cr3C2-NiCr coating led to a significant decrease of fatigue property of the 2Cr10MoVNbN steel substrate. When the stress amplitude was less than 500 MPa, the reduction of fatigue life was more than 75% and the fatigue strength decreased about 134.7 MPa. Fatigue origins of the as-sprayed sample with the presence of Al2O3 particles were at the coating-substrate interface.
出处
《机械工程材料》
CAS
CSCD
北大核心
2009年第6期85-89,共5页
Materials For Mechanical Engineering
