HEAT TREATMENT OF PISTON RINGS, MANUFACTURED FROM HIGH-QUALITY SYNTHETIC CAST IRON

The technology of obtaining piston rings from oil blanks, cast in sandy-clay and metal forms from high-quality cast iron is considered. The mode of heat treatment of oil blanks and the heat-setting of the ring lock in order to obtain the optimal value of elasticity is also noted. The tangential tension force (tensile force) should be in the range of 20-22 kg. The heating temperature of the rings should be in the range of 550-570°С and the exposure time (holding time) in the thermo-fixer is 90 mm. The piston rings of gas-motor compressors are subject to strict requirements on the structure of the metal, surface cleanliness and geometric dimensions. Analysis of the known technological processes showed that the casting of rings is carried out from individual blanks and oil in sandy forms. Production of piston rings with a diameter of 320 mm from high-quality cast iron, on a charge that does not contain blast furnace iron, due to the cost-effectiveness of using low-silicon and low-carbon metal waste. At the same time, the tasks were set for mastering the technology of smelting iron without blast iron, obtaining high-quality homogeneous cast iron, while applying heat treatment of oil blanks and thermification of ring elasticity. The table of parameters of heat-setting was made in different versions.