Cr3C2对45钢表面超音速火焰喷涂制备的Ni基合金涂层热态抗磨损性能的影响

Effect of Cr_3C_2 Addition on Thermal Wear Resistant Performance of High Velocity Oxygen Fuel Sprayed Nickel-based Alloy Coating on 45 Steel Substrate

采用JP8000型超音速火焰喷涂设备(HVOF)在45钢基体上制备了不同Cr_3C_2含量的镍基合金涂层,利用金相显微镜、X射线衍射仪、扫描电子显微镜及能谱仪等仪器对涂层组织进行分析,并测定其硬度;采用CFT-Ⅰ型材料表面性能综合测试仪进行摩擦磨损实验,分别测量在50℃、100℃、150℃、200℃、250℃、300℃温度条件下各涂层的摩擦系数及磨损量。结果表明:当摩擦磨损温度在250℃以下时,镍基合金涂层的摩擦系数和磨损量由于氧化物薄膜的产生,呈现出随温度升高而下降的趋势,而温度达到250℃及以上时产生了严重的粘着磨损,磨损性能随之降低;在镍基合金中添加一定量的Cr_3C_2,可生成Cr_7C_3、CrB等多种硬质相,对涂层起到强化作用,改善了涂层在热态条件下的耐磨损性能;镍基合金中Cr_3C_2的添加量在37.5%左右时,涂层的综合性能优良。

Ni-based alloy coatings with different Cr 3C 2 content were prepared on the 45 steel substrate by using JP8000 type high velocity oxygen fuel(HVOF)spraying equipment.The microstructure of the coatings was analyzed by means of metallographic microscopy,XRD,SEM and EDS,and its hardness was also measured.The friction and wear tests were carried out by CFT-type material surface performance tester.The friction coefficient and wear rate of the coatings were measured at 50℃,100℃,150℃,200℃,250℃and 300℃respectively.The results showed that the friction coefficient and wear rate of Ni based alloy coating decreased with the increase of temperature due to the formation of oxide films when the temperature was below 250℃.If the temperature reached 250℃and above,it produced serious adhesive wear,and the wear performance decreases.When a certain amount of Cr 3C 2 was added to the nickel base alloy,it could produce Cr 7C 3,CrB and other hard phases,which played a strengthening role on the coating and caused wear resistance improvement of the coating in hot state.When the content of Cr 3C 2 was about 37.5%,the comprehensive properties of the coating were excellent.