EXAMINATION OF CAVITATION EROSION PARTICLES MORPHOLOGY IN CORROSIVE WATERS

Karrab, S. A.; Doheim, M. A.; Aboraia, Mohammed S.; Ahmed, S. M.

doi:10.21608/jesaun.2012.114620

EXAMINATION OF CAVITATION EROSION PARTICLES MORPHOLOGY IN CORROSIVE WATERS

Document Type : Research Paper

Authors

¹ Mining and Metallurgical Engineering Department, Assiut University, Assiut 71516, Egypt

² Mechanical Engineering Department, Faculty of Engineering, Majmaah University ,Saudi Arabia

10.21608/jesaun.2012.114620

Abstract

Wear particles produced by vibratory cavitation erosion tests on 1045 carbon steels in three different corrosive media: distilled water, tap water and 3 % NaCl water were analyzed. Scanning electron microscope (SEM) of wear particles were acquired, forming database for further analysis. This study shows that there is no remarkable difference in the particle size with test solution. However, the frequency distribution of particle sizes differed with the test solution. It is the highest at small sizes for tap and distilled water. While for salt water, it is the highest for the larger sizes (larger than 50 µm). All the particles, irrespective of solution, manifested similar morphological features such as lamellar shape, crack propagation on the particle surface and secondary cracks. This indicates that the particles are produced by a single mechanism, namely, fatigue. With regard to the role of corrosion in the development of cavitation erosion, it was most pronounced in the case of salt water. It was found that dissolution of ferrite acts as areas of stress concentration which give rise to crack initiations. This gives a strong impetus to the crack initiations.

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