The simulated seawater was confected and the composition was shown in Table2. The specimens were cut to10×10-1.5 mm3 by diamond paste, degreased by acetone and then dried. The quality of the specimens for the test of quality change rate was measured by the electric scales. Every time before the quality measurement, the specimens were required to be cleaned to remove the
corrosion products covered on the surface of B4C ceramic and then were dried in the oven, finally measured and recorded the quality data. The quality change rate was commutated by the equation V = ΔW/S0 × t, V is the quality change rate, ΔW is the change of specimen quality, S0 is the superficial area and t is the corrosion time. Polarization curves were recorded starting from the electrode corrosion potential at a scanning rate of 2mVs-1 of B4C composite ceramic(BC5 used in corrosion test)immersion in the simulated seawater for1,3,7, 11 and 20 days, respectively.