Improvement of Wear Resistance of Cylinder Liner in Large Marine Diesel Engine

Abstract

We have investigated the merits of porous chromium plating as a protection against the wear of cylinder liner, which is increasing by the use of low grade fuel oils for large marine diesel engines. d liners (over 500mm in diameter) fitted experimentally on an actually servicing ship cleared up the following facts. (1) Porous chromium plated liners not only have remarkable wear resistance (about 1/3 of the wear rate of cast iron liner) but also decrease wear of corresponding piston ring to a large extent. (2) Wear in porous chromium plated liners is mainly due to the corrosion by acid corrosive products (chiefly H_2SO_4) produced on their interior wall. But the growth of the corrosion by acid can be arrested by adjusting the cylinder oil supply. In view of these results, porous chromium plated liners not only increase wear resistance of the cylinder liners but also prolong the intervals of overhauling in large marine diesel engines, compared with the case of cast iron liners.