A microstructure of C15 steel examined from metallographic standpoint can be observed in Figure 1. This sample has been heat-treated by liquid carbonitriding and heat treat in the same way. C15 steel is a martensitic carbon steel that can be used for a variety of applications, including bearings and fluid power products.
Figure 1 shows ferrite and carbide microstructures for the C15 steel sample. It can be seen that the carbide structure is characterized by a uniform size and shape, and a uniform distribution of free and combined carbon in the microstructure. The ferrite structure is characterized by some pearlite lamellae, as well as a few isolated ferrite grains. It is likely that the pearlite structure was created by the heat-treatment, while the isolated ferrite grains are the result of carbide precipitation.
Overall, the microstructures of C15 steel are quite uniform, which is consistent with the metallurgical properties of C15 steels. The uniformity of the microstructures is created by the process of liquid carbonitriding and heat treating, which allows for consistent and even precipitation of carbides. This also provides for a consistent hardness throughout the material, as well as improved ductility, which is especially important when this material is used in applications such as bearing and fluid power components.
In terms of mechanical properties, the C15 steel sample is most likely tempered at a temperature that is below the tempering temperature of its full hardening cycle. This is because the full hardening cycle of the steel would result in a higher hardness than what is evident in Figure 1. The tempering process reduces the hardness of the steel, making it more suitable for use in applications that require strength and durability.
Overall, the microstructure of C15 steel, as seen in Figure 1, is quite uniform and consistent. It consists of a uniform distribution of ferrite lamellae and carbide particles, and is created by liquid carbonitriding and heat treating. This provides for a consistent hardness throughout the material, as well as increased ductility, which is important for components that require strength and durability.
