Investigation into the erosion damage mechanism of High-Temperature, High-Pressure, and High-Speed gasflow on metal surfaces

High-temperature, high-pressure, and high-speed gasflow can accelerate material loss on metal components, shortening their service life. To explore the mechanisms behind this erosion damage, a stepwise experimental approach was conducted, using high-pressure, high-speed argon gas and high-temperature, high-pressure, high-speed propellant gas to erode the surfaces of gun steel specimens. The investigation centered on the interaction of thermal, chemical, and mechanical factors. An analysis of the surface after erosion was conducted using scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), X-ray diffractometry (XRD), and electron backscatter diffraction (EBSD) to evaluate the morphology of the surface, distribution of elements, and composition of phases. The findings indicate that the primary cause of material loss is the mechanical effect of the gasflow scouring. While the initial impact on smooth surfaces is minimal, it becomes significant once cracks develop and the surface becomes rough. This leads to a continuous erosion process and a wear phenomenon of the surface material. The white layer promoted by the thermal and chemical actions is partitioned into two distinct layers. The outer white layer is made up of the austenite, the cementite, and the iron oxide. It is very brittle, easily broken, and flaked. The inner white layer consists of a fine-grained mixture of martensite and austenite. During the rapid and intense heat transfer, the shallow layer experiences thermal stresses, forming small cracks that weaken the integrity of the surface. Ultimately, due to the combined impact of three factors, the surface of the component fractures and deteriorates inwardly.