The Corrosion Reason and Solution in Slurry Pump

Katherine Hou

Shijiazhuang Naipu Pump Co., Ltd     

Tel: +86-311-83802338 Fax: +86-311-87162902 

Cellphone/ WeChat/ WhatsApp: +86-15028111051 

Skype: katherine_naipump URL: www.naipump.com 

Email: katherine@naipump.com 

The Corrosion Reason and Solution

1. Electrochemical corrosion:
   The pump flow channel using same metal materail.
   Small wearing parts as an anode made of low-potential metal. Large parts as the cathode made of high-potential metal.

2. Uniform corrosion:
   Using suitable material(including non-metal). Consider sufficient corrosion allowance when designing the pump.

3. Intercrystalline corrosion:
   Annealing treatment for stainless steel materail part. or using ultra-low carbon stainless steel.

4. Pitting corrosion:
   Using Mo steel(usually 2.5%Mo). And Mo content should be increased accordingly while Cl content and temperature rise.

5. Crevice corrosion:
   Using high content of Cr, Mo metal.
   12% Cr steel <17% Cr steel <Austenitic SS< Austenitic 316SS.

6. Stress corrosion:
   High Ni content (Ni> 25%-30%) of austenitic Cr-Ni steel.

7. Erosion corrosion:
   Ferrite Cr steel <austenite-ferritic steel> austenitic steel.

8. Cavitation corrosion:
   Using cavitation resistant material. Such as Hard alloy, Phosphor bronze, Austenitic SS, 12% chrome steel. etc.

How to prevent corrosion problems in slurry pump?

1. Material selection:
   Factory experience. Similar applications in other site. Experiecne of pump manufacturers. Appropriate documents etc.

2. Coating technology:
   Widely used coating Fusion Bonded Epoxy (FBE) and Polytetrafluoroethylene (PTFE). The effectiveness of the coating is dependents on the type of coating, the preparation of the coating, the application of the coating, the type of corrosion involved, and the type of liquid to which the coating is exposed.