Piston Body

Working conditions: The piston works under high temperature, high pressure, high speed, and poor lubrication conditions. The piston is in direct contact with the high-temperature gas. Therefore, the heating is serious and the heat dissipation conditions are very poor. Therefore, the temperature of the piston is very high during operation, the top is as high as 600~700K, and the temperature distribution is very uneven; the top of the piston bears a large gas pressure, especially The work stroke pressure is the largest, which makes the piston produce an impact and bear the effect of side pressure; the piston reciprocates at a high speed (8~12m/s) in the cylinder, and the speed is constantly changing, which produces The large inertia force causes the piston to be subjected to a large additional load. Pistons working under such harsh conditions will deform and accelerate wear, as well as additional load and thermal stress.

Requirements: 

(1) It must have sufficient rigidity and strength, and reliable force transmission:

(2) Good thermal conductivity, high pressure resistance, high temperature resistance and abrasion resistance

(3) The mass is small, light in weight, and the reciprocating inertia force is minimized as much as possible. Aluminum alloy materials basically meet the above requirements. Therefore, pistons generally use high-strength aluminum alloys, but high-grade cast iron, heat-resistant steel, and 3Cr13 are used in some high-pressure compressors.