Cavitation erosion, mainly refers to the construction machinery due to long-term engineering use, resulting in the outer layer off the formation of machinery, the formation of pitted and needle-like small holes.These cavitation are inevitable.
The cavitation erosion of diesel engine means that the surface of wet cylinder liner contact with coolant is destroyed into some needle-like holes, which will grow larger and deeper with the passing days and finally develop into cracks.Cavitation erosion is generally caused by the high frequency vibration of the cylinder liner, and mechanical vibration causes the pressure change of the coolant, resulting in bubbles and rupture of the coolant.
For diesel engine cavitation, we can take the following measures:
1. Reduce the vibration of cylinder wall. The smaller the piston – cylinder liner fit clearance, the smaller the piston’s impact on cylinder wall, the less the vibration of cylinder wall and the less the cavitation.
2. Wall cooling system shall be adopted as far as possible. The design of water jacket shall ensure that the cylinder liner is sufficiently cooled, and the cooling water flow shall flow to the cylinder liner in the tangential direction to avoid short circuit of water flow, vortex free zone and cooling dead zone.
3. Cathodic protection prevents electrochemical corrosion of cylinder liner.There are two specific operation methods: one is to use the impressed current to make the surface of the cylinder liner become a cathode, the other is the surface of the cylinder liner suitable for welding zinc or magnesium alloy belt.