Study the effect of the size of abrasive sand grains of angular type in fluids on the scratch corrosion rate of the metal surface

Abstract

This research deals with the effect of the size of abrasive sand grains of the angular and semi-angular type in fluids on the scratch corrosion rate of two metals "carbon steel and pure aluminum" using a rotating disc in a closed water basin and at two rotational speeds of medium "395 r.p.m" and high "915". r.p.m" for two and a half hours.
Five different sizes of abrasive granules were taken, and they are respectively "250.5, 711,355, 970.5, and 191" microns. They were added to the liquid at a concentration of 20% for each size.
  It is concluded from the research that the self-protection sound of the aluminum metal reduced the mechanical corrosion rate by half compared to carbon steel after half an hour of surface exposure to abrasive particles, although aluminum is a softer and softer metal with less hardness. The largest rate of corrosion is (0.006 gm), the difference in weight occurred when the aluminum surface was exposed to abrasive grains of size "711 μm" at a speed of "395 r.p.m" and that small particles of "91 μm --------355 It had a small effect and at a constant level. The abrasive granules of "711 μm" size had a very large effect, and then this effect began to decrease when using the "970.05 μm" size because of the heavy weight of these granules, which led to their sedimentation at the bottom of the basin and on the rotating disc instead. from its impact on the surface of the samples. On the other hand, the medium speed "395 r.p.m" is more effective on the corrosion rate than the high speed, because the increase in speed led to the abrasive particles flying away from the surface of the metal.