在H13钢表面分别采用超音速火焰喷涂Cr3C2-NiCr涂层和氧-乙炔火焰喷熔Ni60A涂层,观察了喷涂粉末和涂层的微观结构,测试了两种涂层在常温及600℃下与基体的结合强度和涂层在600℃下的摩擦磨损行为.结果表明:Cr3C2-NiCr涂层和Ni60A涂层表面均匀平整,无裂纹等缺陷,Cr3C2-NiCr涂层与基体之间的结合方式是以机械结合为主的"微冶金"结合,而Ni60A涂层与基体之间的结合方式为冶金结合;Cr3C2-NiCr涂层的显微硬度值大于Ni60A涂层;随着温度的升高,涂层的结合强度均有所下降,但Ni60A涂层的下降幅度大于Cr3C2-NiCr涂层,在常温和600℃下Ni60A涂层与基体的结合强度都高于Cr3C2-NiCr涂层;在H13基体表面喷涂Cr3C2-NiCr和Ni60A涂层,均能提高其表面高温耐磨性,但Cr3C2-NiCr涂层的效果要好于Ni60A涂层.%The comparative investigation is carried out for two types of thermal spray coatings on H13 steel surface-the high velocity oxy-fuel sprayed Cr3C2-NiCr coating and the oxyacetylene flame sprayed welding Ni60A coating.The microstructure of the coatings and powders is observed.The adhesive bonding strength of the two coatings is examined at room temperature and 600 ℃,and the abrasive wear behavior of the coatings is also investigated at 600 ℃. The results show that the surface of both Cr3C2-NiCr coating and Ni60A coating are even and flat,no cracks or other critical defects are found.The bonding mode between Cr3C2-NiCr coating and its substrates is the combination of micro metallurgy dominated with mechanical bonding, and the mode for Ni60A is metallurgical bonding.It also suggests that the micro hardness value of Cr3C2-NiCr coating is greater than that of Ni60A coating.The bonding strength of the coatings is decreased with the increase of temperature,but the declining pace of the Ni60A coating is faster than that of the Cr3C2-NiCr coating.The bonding strength between Ni60A coating and its substrate is higher than that of Cr3C2-NiCr coating at room temperature and 600℃.It can be concluded that both the sprayed Cr3C2-NiCr and Ni60A coating can improve high temperature wear resistance of the surface,but the effect of Cr3C2-NiCr coating is better than that of Ni60A coating.
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