Heat training nodular cast iron with high silicon content - in mfg. piston rings and bushes for high performance IC engines, involves using controlled cooling rate

摘要

The parts are heated to not >970 degrees C., and then cooled at a speed where lambda is less than 0.07, where lambda is defined as the cooling time from 800 degrees to 500 degrees C. in seconds x 10-2. A martensitic structure can be obtd. from high Si nodular iron without the need for other alloying elements. Typically the cast iron contains 4.6-5.1% Si and approx. 3% C.