The piston of a large marine low-speed diesel engine is usually a
crosshead type.
The heat treatment process by normalizing and annealing, and
iron pearlite are ferrite organization, has good heat resistance.
Piston
alloy quenched and tempered steel has better heat resistance and corrosion
resistance. The skirt with nodular cast iron annealing treatment, with good wear
resistance.


The working condition of the piston is rather harsh, it is with a temperature of 1400-1800 DEG C, and the pressure



Up to 13MPa gas phase contact, resulting in a large thermal stress and alternating mechanical stress
It is seriously corroded by the gas, and it has strong friction and impact with the cylinder wall under the condition of boundary lubrication. 1 times


The piston is exposed to high temperature, high pressure and strong corrosive gas, so it is required to have sufficient strength and hardness.


Good heat resistance and thermal conductivity, high fatigue strength and corrosion resistance.
In order to reduce reciprocating inertia force.





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