Morphology and mechanism of cavitation degradation of gray cast iron surfaces with lamellar graphite

Abstract

Gray cast iron parts with lamellar graphite in contact with liquid media can be degraded by cavitation erosion. The TIG remelting technique of the surface of these parts is an efficient way to improve the lifespan of engineering components working in cavitation environments. This paper illustrates the cavitation erosion behavior of a gray cast iron with a microstructure composed of a pearlitic matrix, a small proportion of phosphorous eutectic and lamellar graphite. The cavitation test was performed using an ultrasonic vibrator, and the liquid chosen was water from the public network. Based on the cavitation curves and the examination of the surfaces tested by optical and scanning electron microscopy, a sequence of damage models is proposed to explain the behavior of cavitation erosion.