Study on Friction and Wear Characteristics of K360 Wear-Resistant Steel PK—Y25 Surfacing Layer

The tribological performance of K360 wear-resistant steel PK—Y25 surfacing layer has been studied under different sliding velocities and loads in this paper. The results show that the wear resistance of the K360 - PK—Y25 surfacing layer is excellent under dry friction. The wear scar diameter and friction coefficient decrease significantly with the increase of sliding velocities, while the wear rate and friction heat increase. The dry sliding wear test of K360 - PK—Y25 surfacing layer with different loads show that the wear scar diameter increases linearly with the increase of healthy load, and the friction coefficient also increases. The wear scar of K360 - PK—Y25 surfacing layer under dry friction is mainly adhesive wear and oxidation wear, and the wear chips are mainly composed of two phases of complex compounds.
    
K360 wear-resistant steel is a kind of high carbon high chromium alloy steel and its microstructure consists of a hard martensite, and a small amount of fine carbides and austenite, with good wear resistance. PK—Y25 surfacing layer, the main ingredient of which is K360 wear-resistant steel and other alloy elements, has excellent wear resistance and is widely used in engineering machinery and wear parts. The research on tribology of wear-resistant surfacing layer is of great significance to improving the service life of wear-resistant parts.
    
This paper mainly studies the friction and wear characteristics of K360 wear-resistant steel PK—Y25 surfacing layer under different sliding velocities, loads and wear environments.
    
Experimental Method
The key material of K360 wear-resistant steel PK—Y25 surfacing layer used in the experiment is provided by the research institute. After grinding and polishing the sample surface with diamond sandpaper #800, the sample surface becomes smooth, and the surface roughness Ra is determined to be 0.1 um by a surface roughness tester. The sample is a flat surface of 100mm x 100mm x 6mm. A pin-ring friction–wear tester and a high-precision digital display torque sensor are used for testing. The test temperature of the sample surface is 25 °C and the atmosphere is airtight.
    
The test was conducted under different sliding velocities of 10 m/s, 20 m/s, 30 m/s and 40 m/s, different loads of 10 N, 15 N, 20 N and 25 N, while the wear track is 0.7 mm, and the test time is 60 s.
    
Results and Discussions
The friction coefficient and wear scar of K360 wear-resistant steel PK—Y25 surfacing layer under dry friction
    
The friction coefficient and wear scar of K360 - PK—Y25 surfacing layer under dry friction are shown in Figure 2.
    
From Figure 2a and Figure 2b, it can be seen that with the increase of sliding velocity V, the wear scar and friction coefficient of K360 - PK—Y25 surfacing layer decrease significantly. When the sliding velocity is 10 m/s, the wear scar of K360-PK—Y25 surfacing layer is the largest. When the sliding velocity is 40 m/s, the wear scar of K360 - PK—Y25 surfacing layer is the smallest. With the increase of sliding velocity, the wear scar diameter decreases and finally reaches a stable value.
    
The tribological performance of K360 wear-resistant steel PK—Y25 surfacing layer under different sliding velocities and loads was studied. The results show that the wear reaction of K360 - PK—Y25 surfacing layer under dry friction is excellent, and the wear scar and friction coefficient decrease significantly with the increase of sliding velocity. The dry sliding wear test of K360 - PK—Y25 surfacing layer with different loads show that the wear scar diameter increases linearly with the increase of healthy load, and the friction coefficient also increases. The wear scar of K360 - PK—Y25 surfacing layer under dry friction is mainly adhesive wear and oxidation wear, and the wear chips are mainly composed of two phases of complex compounds.

---