Comparison among Oil Spectral Data of Six Types of Marine Engine

In order to monitor wear condition of marine engine, 1032 oil samples are taken from 6 types of 235 engines. With the Spectroil M type Instrument, elements' concentrations of every oil are analyzed. By the statistic tool, the calculation data contains average value and standard deviation of every type of marine engine wear, contamination and additives elements. The correlation coefficient of main elements in oil has been used to study wear characteristic of friction pairs, contamination source and additives depletion. The average value and standard deviation of main wear element in different types of engines oil are different. The ratio of maximum average value to minimum one for Fe, Pb and Cu are 6.3, 4.3 and 2.4 separately. The ratio of maximum standard deviation to minimum one for Fe, Pb and Cu are 19.7, 1.8 and 3.8 separately. As additives element of P, Ba and Zn, their correlation coefficient is more than 0.8. Fe and Cr of which crankshaft and piston rings are made are best correlation in wear elements. The good correlation coefficient elements also are Pb and Cu, Fe and Pb, Fe and Cu. Bearings and thrust washers contain Cu and Pb. The wear of bearings and shaft concurs at working time. Na and Mg caused by seawater have higher correlation coefficient than other elements.