Cavitation Damage to Centrifugal Pump Impellers During Operation With Liquid Metals and Molten Salt at 1050–1400 F

Abstract

Three centrifugal pump impellers fabricated of Inconel were subjected to endurance testing under cavitating conditions with sodium and with molten salt (fused fluorides) at temperatures of 1050–1400 F. The tests were run (one with sodium and two with molten salt) at or near pump design head and flow conditions to establish the extent of impeller damage sustained during long periods of operation and to observe the effects upon performance. Descriptions are provided of the test impellers and volutes, of the experimental apparatus, and of the test operations. The cavitation damage is described by the effects on hydraulic performance and with photomicrographs and metallurgical analyses. Damage was manifested by the formation of pits in excess of 1/4 in. in depth. No change in performance was detected.