Construction Productivity Advancement Research (CPAR) Program: Cavitation- and Erosion-Resistant Thermal Spray Coatings
Abstract
This study demonstrated the effectiveness of thermal spray cavitation and erosion-resistant metal coatings for hydroelectric and utility plant turbines and pumps. Of 21 thermal spray coatings tested, Stellite(trade name) 6 applied by the high-velocity oxyfuel (HVOF) process had the lowest cavitation rate (11.7 mg/h). This was higher than the corresponding rate of 3.2 mg/h for 308 stainless steel weld reference. In slurry erosion wear testing, the volume loss for HVOF-applied Stellite(trade name) 6 was 5.33 mm3/h, much lower than volume losses for 304 stainless steel and A572 carbon steel. The field applicability of Stellite(trade name) 6 was successfully demonstrated on a hydroelectric pump/turbine. Stellite(trade name) 6 deposited by the HVOF process should be considered for repair of damage resulting from erosion and subsequent cavitation caused by surface roughening. Stellite(trade name) 6 coatings should also be considered for the mitigation of galvanic corrosion. Damage caused by direct cavitation should be repaired by welding. Advanced iron-based alloys such as NOREM(trade name), D-CAV(trade name), CaviTec(trade name), and Hydroloy(trade name) should be considered for use due to their superior cavitation resistance. The use of thermal spray coatings such as HVOF-applied Stellite(trade name) 6 should also be considered for repair of pumps subjected to erosion and subsequent cavitation caused by surface roughening.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1997
- Accession Number
- ADA329272
Entities
People
- Ashok Kumar
- Herbert Herman
- Jeffrey H. Boy
- Patrick March
- Paul Willis
Organizations
- Construction Engineering Research Laboratory