Accession Number : ADA329272

Title :   Construction Productivity Advancement Research (CPAR) Program: Cavitation- and Erosion-Resistant Thermal Spray Coatings

Descriptive Note : Final rept

Corporate Author : CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL

Personal Author(s) : Boy, Jeffrey H. ; Kumar, Ashok ; March, Patrick ; Willis, Paul ; Herman, Herbert

PDF Url : ADA329272

Report Date : JUL 1997

Pagination or Media Count : 149

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.

Descriptors :   *METAL COATINGS, *SPRAYS, *EROSION RESISTANCE, *CAVITATION, TURBINES, PUMPS, HYDROELECTRICITY.

Subject Categories : Coatings, Colorants and Finishes

Distribution Statement : APPROVED FOR PUBLIC RELEASE