Author(s): S. Kioka; T. Takeuchi
Linked Author(s):
Keywords: No Keywords
Abstract: In sea areas covered with ice where active sea ice movement is seen, the degradation/deterioration of marine and coastal structures has been caused by wear, abrasion (including erosion/corrosion), deformation, peeling and other types of damage stemming from ice-related impact and friction. We have especially focused on the deterioration of steel structure caused by friction of sea ice floes. Our previous study revealed the contribution of corrosion was much greater than that of mechanical (adhesive) wear. On the other hand, as a mixture of sand in sea ice has been found in some surveys at sites with severe wear-related damage, the contribution of abrasive wear (one of mechanical wear) caused by interposed particles is also considered possible. In order to examine the influence of abrasive wear, we made sliding wear test between metal material (stainless steel) and artificial ice with interposed sand. We confirmed that the amount of wear of the metal sample increased bi-linearly with increase in sliding distance, and that two kinds of wear states were possible to be defined as “initial wear” and “steady wear”. While the wear rate (amount per distance) did not depend on the sand amount or sand particle size, even a tiny amount of small sand particles had a certain cutting ability, in which case the wear state immediately shifted to steady wear. Tests using natural sea ice samples confirmed that solid matter in the natural sea ice caused abrasive wear. Because the sand in the natural sea ice was so small and in such tiny amount, the only wear state that was observed was the steady state, and the results agreed with the steady wear rate of metal from artificial ice with artificially interposed sand in this test method. As a result of an exposure test of carbon steel (rolled structural steel) in ice covered areas, the wear/corrosion rate in those areas was confirmed to be several times that in normal sea areas.
Year: 2014