Water Side Deterioration Of Diesel Engine Cylinder Liners^★

Heretofore cast iron liners have usually required renewal on account of internal wear. The useful life due to internal conditions will probably be extended by improved inhibition and lubrication. This paper deals with problems in water cooling of Diesel engines. The important factors involved are: dissimilar metals, design, concentration cells at juncture of liners with engine block, variable velocities and temperatures, composition of the liner and cooling water and occasional rapid localized pitting, are apparently of dynamic origin. Ordinary corrosion can be controlled in the closed water cooling system by using chromate or other water-soluble inhibitors in soft water low in organic matter. The "dynamic" pitting referred to above is less common but often much more rapid than any electro-chemical pitting of cast iron known to the authors. This type of pitting is illustrated and described in detail. The pits are free from corrosion products. From, the shape, contour and limited experimental evidence this peculiar pitting is associated with the high frequently "cavitation" effect found in hydraulic systems. High chromate concentration (4000 ppm) has proved beneficial (the railroads report good results with about 2000 ppm chromate) but the final solution awaits further research and probably the application of damping principles in design.