Anti-corrosion Measures for Pump Impeller

Sep. 28, 2021

the pump impeller

The corrosion and wear of the pump impeller is mainly caused by the corrosion and stress corrosion caused by the corrosive gas contained in the conveyed medium. The types of corrosion caused by different conveying media are also different. In order to prevent corrosion and the occurrence of impeller corrosion and wear, the following measures are usually adopted: coating or spraying of corrosion-resistant layer on the impeller surface, selection of stainless steel with strong corrosion resistance as impeller material and improvement of impeller surface quality to solve the problem of corrosion and wear.


Impeller corrosion resistant layer coating

Pump impeller surface coating amorphous nickel-phosphorus (Ni-P) alloy is today a more successful surface corrosion protection coating method. pump impeller surface coating amorphous nickel-phosphorus (Ni-P) alloy as a good corrosion resistance process method.

Due to the ideal amorphous structure and alloy characteristics of the plating, grain boundary corrosion and grain boundary defects are avoided. Plating hardness of HRC50-70 Ni-P alloy plating corrosion resistance, wear resistance and corrosion resistance to hydrochloric acid, sulfuric acid, phosphoric acid and caustic soda.


Corrosion and wear resistant materials

Austenitic stainless steel (such as 1Cr18Ni9Ti) yield strength is low, not suitable for the manufacture of high speed impeller. Suitable as a general low-speed fan anti-corrosion impeller material. In the media containing CO2 and other corrosive gases and smoke, mainly with Cr13 stainless steel. But should pay attention to stress corrosion. The requirement of corrosion resistance pump impeller with high speed is widely used martensitic precipitation stainless steel, such as 0Cr17Ni4Cu4Nb and FV520B.


Spraying of impeller corrosion resistant layer

Pump impeller corrosion resistance spraying surface thermal spraying and plasma spraying, etc. Stainless steel austenitic stainless steel is used for thermal spraying more, such as 1Cr18Ni9Ti, has good processability. In most oxidizing media and some reducing media have good corrosion resistance.

Spraying materials are nickel and nickel alloy wire, powder. Stainless steel wire, powder, etc. Nickel and nickel alloy coating layer of hydrogen sulfuric acid, phosphoric acid, hydrogen cyanide, hydrofluoric acid, acetic acid, ferrous sulfate solution and dry gas and other media, corrosion resistance is good. But for hydrochloric acid, nitric acid, potassium acetate, sulfurous acid and other media, the corrosion resistance is not good.


Pump impeller corrosion resistance there are other methods, such as rubber anti-corrosion coating, epoxy resin coating, etc. Pump impeller wear resistance and anti-corrosion methods are more. Restricted by the working condition of wind operation system and different manufacturing process of impeller, the wear resistance and anti-corrosion method of pump impeller also varies from enterprise to enterprise. We are a pump impeller supplier, please feel free to contact us if you need them.