【摘要】 采用氧-乙炔火焰喷焊在Q235钢上制备NiCrBSi-WC涂层,使用激光对喷焊层表面改性处理后在电炉中进行固体硼硅共渗。通过SEM、XRD、EDS及显微硬度计等对处理前后涂层组织的微观形貌、物相和显微硬度进行分析,使用摩擦磨损实验机研究对比处理前后各涂层的耐磨性能。结果表明:喷焊层表面微孔及夹杂在激光扫描处理后变得平整、致密,涂层主相Ni_2.9Cr_0.7Fe_0.36、FeNi₃成分未变,但主相在晶面排列上具有择优取向性且结晶度提高。WC部分分解为W₂C、W及C,C被固溶进Ni基中使Cr₃C₂等碳化物相增多,淬硬层深度达0.25mm,显微硬度提高到9090MPa,耐磨性能得到提高。在涂层激光重熔的基础上硼硅共渗能够增加Ni₃B、Ni₂B、NiSi等硼化物及硅化物硬质相,平均摩擦系数由0.583降低为0.428,耐磨性较激光处理后提高近1倍。更多还原

【Abstract】 NiCrBSi-WC coating was prepared on Q235 steel using the oxygen acetylene flame spray welding.Afterwards the surface of the spray welding layer was modified by laser followed by solid boronsiliconizing.The microstructure,phase structure and microhardness of the coatings were analyzed by SEM,XRD,EDS and microhardness tester;and the wear resistance of the coating before and after treatment was compared by the friction and wear testing machine.The results show that the surface of the spray welding layer under the laser scanning process becomes smooth and dense.The main phase Ni_2.9Cr_0.7Fe_0.36 and FeNi₃ components of the coating are not changed,but the main phase in the arrangement of crystal plane exhibits the preferred orientation and the crystallinity increases.The WC is partially decomposed into W₂C,W and C.And C is dissolved into the Ni base to increase Cr₃C₂ and other carbides.Thus the hardened layer depth is 0.25 mm and its microhardness increases to 9090 MPa;as a result,the wear resistance of the coating is improved.On the basis of the laser remelting,boronsiliconizing can increase boride such as Ni₃B,Ni₂B,and Ni Si,and silicide hard phase,the average coefficient of friction decreases from 0.583 to 0.428,and the wear resistance is increased by one time compared with that of the laser treated coating.更多还原