Abstract
We studied cavitation erosion of pure titanium (TB270H, TB340C, TB480H), titanium alloy (Ti-6Al-4V) and stainless steel (SUS316) by using a cavitating jet apparatus in seawater and in tap water. The obtained data were compared with those from similar experiments previously carried out in 3% salt water and also de-ionized water. A rotating disk was used. And a vibration test was made using apparatus for pure titanium, titanium alloy (Ti-6Al-4V, Ti-15V-3Cr-3Sn-3Al) and stainless steel (SUS316, SUS316L). The erosion resistance of pure titanium and the stainless steel in tap water was excellent. Whilst the erosion rates in seawater were higher than those in tap water. This suggests that it is necessary to reduce the inspection interval when those materials are used in a seawater pump impeller. Corrosion current density behavior was similar to that of cavitation erosion rate. The corrosion current density of the eroded pure titanium was 1.2 μA/cm2]. This was 2.4 times higher than that of the stainless steel. Relative erosion resistance of these metals was obtained with a cavitating jet, a rotating disk and a vibratory apparatus, which exhibits a good linear relationship against the Vickers hardness value on the logarithmic graph paper.
