Erosion wear means wear phenomenon that material surface is damaged by small and loose flow particle.Its definition can be described as a solid surface material is lostduring relative motion occurs with fluid containing solid particles in contact. Fluid carrying solid particles can be high-speed airflow, also can be a liquid flow, the former produces sandblasting erosion, and the latter is called the slurry erosion. Erosion wear is a common form of modern industrial production, and widely exists in mechanical, metallurgy, energy, building materials, aviation, aerospace and many other industries, which has become one of the important reasons of the material damage or equipment failure。
According to the flow medium and the carrying characteristics, the erosion can be divided into six different types:
1.Sand blasting erosion, namely the gas medium with solid particle erodes materials.The engineering examples such as: Intrusion of dust and sand erode helicopter engine, air transportation material erode on pipeline elbow, pipe exhaust heat exchanger erosion of pulverized coal combustion boiler in power plant;
2.Water erosion (also called rain erosion), namely the gas medium carrying the liquid droplets erodes material, for example: high speed aircraft, and the steam turbine blade drop impact erosion in superheated steam temperature;
3.Slurry erosion, means oil and liquid medium carrying solid particles erode the material surface, the engineering examples are: turbine blades erode in river with much sand & sediment, construction industry, oil drilling, mining, metallurgical，mining and fire power station mud pump，erosion of pump flow components in impurity pump, as well as in the coal gasification, liquefaction (coal oil slurry, coal slurry preparation), conveying and combustion in the pipeline;
4.Cavitation (also known as cavitation erosion), liquid medium carrying dissolved gas or bubbles erode the material. This kind of erosion occurs mainly in water conservancy machinery, such as damage of marine propeller, water pump impeller and the pipeline valve sealing surface;
There are another two types of three-phase flow erosion,i.e.:
5.Gas carrying liquid drops and the solid particle erosion of materials
6.The liquid medium with bubbles and solid particle erosion of materials
Protection of erosion wear
Usually apply pre-coating to protect, the different measures of protection are applied according to the working conditions. There are mainly several kinds at the following:
1.The wear resistant coating or pre-protection wear resistant repair agent
2.The wear resistant ceramic adhesive pastes special wear-resistant ceramic disc for pre-protection
3.Polyurethane elastomers coating
4.Hard surfacing coating, ceramic coating, metal ceramic composite coating and intermetallic compound coating spraying,etc
5.Apply new material with high features