采用2 kW光纤碟片激光器在3Cr13不锈钢刀具表面进行同轴送粉激光熔覆高铬铁基合金，以提高刀刃的硬度.通过SEM，EDS，EPMA，XRD分析了熔覆层的显微组织及相组成，采用显微硬度仪进行了硬度测试.结果表明，在凝固的过程中，成分过冷和散热速度的不同，组织大致分为枝晶区、细晶共晶区、粗晶区三个区域，各区域内均分布有（Fe，Cr）7C3，可增加熔覆层的硬度和耐磨性.由于各区域内晶粒的大小不同，使得熔覆层内硬度呈阶梯分布.Ni元素的加入，促进熔覆层中基体奥氏体化，在刀具使用过程中可对高硬度的碳化物起韧性缓冲作用，从而保证了熔覆层的综合力学性能.
A high chromium iron-base alloy with the coaxial powder laser coating is implemented on the surface of the 3Cr13 stainless steel blade by using 2 kW fibre-optical disc laser to improve the hardness of the blade. SEM, EDS, EPMA and XRD are used to analyze the microstructure of the cladding layer and the microhardness is tested. The results show that the cladding layer is well-formed and metallurgically bonded with the substrate without defects such as cracks, porosity and so on. With the change of the heat dissipation and the constitutional supercooling, microstructure can be roughly divided into three regions:dendritic region, eutectic fine grain region and coarse grain region. The carbides of (Fe,Cr)7C3 is distributed in each region to increase the hardness and abrasion resistance of the cladding layer. As the size of the grain in each region is different, the hardness of the cladding layer is differently distributed. While, the addition of Ni element promotes the austenization of the matrix in the cladding layer. It can play a role in the toughness of the carbides with high hardness during the use of the knife. Thus, the comprehensive mechanical properties of the cladding layer are obtained.
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