Influence of microstructure on mass loss caused by acoustic and hydrodynamic cavitation

TL;DR

This study examines how microstructure influences material erosion due to acoustic and hydrodynamic cavitation in stainless steel, revealing microstructure-dependent erosion in acoustic cavitation but not in hydrodynamic cavitation.

Contribution

It provides a comparative analysis of cavitation effects on different microstructures using innovative experimental setups including X-ray compatible ultrasonic testing.

Findings

Microstructure affects mass loss in acoustic cavitation.

Hydrodynamic cavitation causes similar erosion regardless of microstructure.

Experimental apparatus allows detailed cavitation damage analysis.

Abstract

The proposed study investigates the damage mechanisms of martensitic stainless steel X3CrNiMo13-4 exposed to cavitation using two complementary experimental apparatus: ultrasonic horn (MUCEF) and hydrodynamic tunnel (PREVERO). Cavitation testing has been carried out on two different metallurgical states: QT780 and QT900 corresponding to coarse and fine microstructure respectively. Acoustic cavitation erosion tests have been performed on the MUCEF equipment inspired from the ASTM G32 standards but specially designed to be installed inside X-Ray tomographs. The ultrasonic horn operates at 20 kHz and the tested specimen is located at 500 $\mu$m from the horn tip. Hydrodynamic cavitation erosion tests were conducted with classic experimental conditions of PREVERO device: a cavitation number of 0.87 corresponding to a flow velocity of 90 m.s-1 and an upstream pressure of 40 bars. For acoustic cavitation, mass loss has been identified as dependent of the microstructure while for hydrodynamic cavitation the mass loss is identical whatever the microstructure size.