How to maintain the submersible pump corrosion – proof submersible pump

Core tip: any water pump in the use of the process will produce corrosion phenomenon?If stainless steel pumps, fluoroplastic pumps, ordinary cast iron pumps.We shenlong pump industry can not 100% guarantee that the pump will not be corroded, only to reduce the degree of corrosion.So what kind of corrosion does the pump have?How to prevent it?

Methods to prevent corrosion of water pumps:

1) abrasion corrosion

refers to the erosion corrosion of metal surface by high-speed fluid.Fluid erosion corrosion is different from that caused by the presence of solid particles in the medium.Water pump in the operation will produce wear, so we should try to use good wear resistance material, in order to reduce its wear corrosion.Of course, the corrosion resistance of different materials is also different.

2) electrochemical corrosion

electrochemical corrosion refers to the electrochemical process by which a battery is formed on the contact surface of different metals due to the difference in electrode potential between the metals, resulting in corrosion of the anode metal.One of the measures to prevent electrochemical corrosion is to use sacrificial anode to protect the cathode metal.Second, the flow channel of the pump had better use the same metal material.

3) intergranular corrosion

intergranular corrosion is a kind of local corrosion, mainly refers to the precipitation of chromium carbide between stainless steel grains.Intergranular corrosion is very corrosive to stainless steel.Intergranular corrosion prevention measures are: stainless steel annealing treatment, or the use of ultra-low carbon stainless steel (C< 0.03%).

4) uniform corrosion

uniform corrosion refers to the occurrence of uniform chemical corrosion on the whole metal surface when the corrosive liquid contacts the metal surface.This is the most common type of corrosion and the least harmful type.Measures to prevent uniform corrosion are to take appropriate materials (including non-metals) and consider adequate corrosion allowance in pump design.

5) crack corrosion

crack corrosion is a kind of local corrosion, refers to the crack is filled with corrosive liquid, due to the decrease in the gap oxygen content and/or pH value of the local destruction of the metal dull film caused by corrosion.The use of metal with high Cr and M0 content can prevent or reduce the occurrence of crack corrosion.

6) spot corrosion

spot corrosion is a local corrosion.Due to the local failure of the metal dull film, a local area on the metal surface quickly forms a hemispherical pit, which is called pitting corrosion.The pitting corrosion is mainly caused by Cl 1.Pitting corrosion can be prevented by using steel containing M0 (usually 2.5% Mo), and the content of M0 should increase with the increase of Cl 1 content and temperature.

7) stress corrosion

stress corrosion refers to a local corrosion caused by the combined action of stress and corrosive environment.> 25% to 30%) of austenitic Cr – Ni steel.

8) cavitation corrosion

pump cavitation corrosion caused by corrosion is called cavitation corrosion.The most practical and simple way to prevent cavitation corrosion is to prevent cavitation.But the water pump cavitation can not be prevented, pump operation more or less will produce cavitation corrosion, for those who often produce cavitation corrosion pumps, can be used to resist cavitation materials, in order to increase its cavitation resistance.