超音速火焰喷涂Cr_3C_2/NiCr、Stellite6、Inconel625、Inconel718涂层耐冲蚀性能研究

Study on the Erosion Resistance of Cr_3C_2/NiCr,Stellite6,Inconel625 and Inconel718 Coatings Sprayed by HVOF

采用超音速火焰喷涂技术,在15Cr_2Mo合金钢上制备了Cr_3C_2/NiCr、Stellite6、Inconel625、Inconel718涂层。测定了涂层的显微组织、结合力、显微硬度、孔隙率。研究了涂层耐固体颗粒冲蚀性能。结果表明,Cr_3C_2/NiCr涂层在结合力、显微硬度和孔隙率方面均优于其他涂层。同时,Cr_3C_2/NiCr耐固体颗粒冲刷性能最好,其冲蚀试验失重量仅为基体15Cr_2Mo的20%左右。Cr_3C_2/NiCr涂层显微组织中,高硬度的碳化物Cr_3C_2陶瓷相以多边形弥散分布在较软的基体NiCr合金相上。固体颗粒冲刷试验后,Cr_3C_2/NiCr涂层表面磨痕比较明显,但是没有发生明显的涂层分层剥落现象。优异的微观结构、细小的硬质颗粒以及较低的孔隙率等因素对涂层耐冲蚀性的显著提高起着关键作用。Cr_3C_2/NiCr涂层应用于冲蚀磨损环境,可有效提高部件寿命。

Cr3C2/NiCr,Stellite6,Inconel625and Inconel718coatings were applied to a15Cr2Mo steel substrate by means of high velocity oxygen fuel spraying(HVOF).The microstructures,adhesion strength,porosity,micro-hardness of the coatings were analyzed and erosion tests were conducted to study the erosion resistance of the four coatings.The results show that the Cr3C2/NiCr performs best in adhesion strengths,micro-hardness and porosity.Meanwhile the erosion resistance of Cr3C2/NiCr is best and its weight loss is only20%of the weight loss of15Cr2Mo steel during the erosion test.The microstructure of crosssection morphology of Cr3C2/NiCr shows that the hard carbide Cr3C2is distributed on the soft NiCr phase in the form of polygons.After the erosion test,there are obvious erosion marks,but the coating clearly did not peel off.The Cr3C2/NiCr coating shows good erosion resistance because it has an ideal microstructure,finer carbide hard particles,low porosity,etc..Applying the Cr3C2/NiCr coating in erosion environments greatly improves the service life.