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The erosion-corrosion of carburized and untreated low alloy steel (AISI 5117) has been investigated using slurry whirling-arm test rig. Erosion-corrosion tests were carried out in slurries composed of sand particles and either tap water or 3 % NaCl solution. The tests were carried out with particles concentration of 1 wt% and slurry stream impact velocity of 15 m/s. Silica sand having a nominal size range of 250-355 μm was used as an erodent. It has been shown that the erosion and erosion-corrosion resistance of AISI 5117 low alloy steel can be effectively improved by carburizing for all impact angles. However, the effectiveness of carburizing was the highest for an impact angle of 45°, where the erosion and erosion-corrosion resistance were increased by 60-40 %, respectively, compared with that of the untreated material. The results showed that the treated and untreated specimens behaved as ductile materials under erosion and erosion-corrosion tests, and the maximum mass loss occurred at an impact angle of 45°. SEM analysis showed that the erosion tracks developed on the untreated specimens were wider and deeper than that formed on the carburized specimens for erosion and erosion-corrosion tests. [ABSTRACT FROM AUTHOR]

Slurry erosion performance of detonation gun (D-gun) spray ceramic coatings (AlO and AlO-13TiO) on CF8M steel has been investigated. Slurry collected from an actual hydro power plant was used as the abrasive media in a high speed erosion test rig. Attempt has been made to study the effect of concentration (ppm), average particle size and rotational speed on the slurry erosion behaviour of these ceramic-coated steels under different experimental conditions. The analysis of eroded samples was done using SEM, XRD and stylus profilometry. The slurry erosion performance of the D-gun spray AlO-13TiO-coated steel has been found to be superior to that of AlO-coated steel. Both the coatings showed brittle fracture mechanism of material removal during the slurry erosion exposure. [ABSTRACT FROM AUTHOR]

Erosion resistance of four types of cast iron of different microstructures and graphite morphologies (viz., grey cast iron, compacted graphite iron, spheroidal graphite iron and austempered ductile iron) was evaluated in three different erosive media. Results indicate that austempered ductile iron has the highest erosion resistance in all three media, followed by spheroidal graphite iron, compacted graphite iron and grey cast iron, in that order. Graphite morphology has a significant effect on the erosion resistance of these irons in quartz-water and iron oxide-oil slurry. However, the matrix microstructure determines the erosion resistance of these irons in quartz-oil slurry. The parameter H/E (which is the ratio of the Brinell hardness number to Young's modulus of the material) has been found to be a good indicator of erosive wear in quartz-oil slurry. [ABSTRACT FROM AUTHOR]