Thermocyclic Strength of Gray Cast Iron SCh20 at High-Temperature Heat Shifts

摘要

The thermocyclic strength of the SCh20 gray cast iron (analog of A48-30B AISI cast iron) is studied to predict the durability of casting molds made of SCh20 under conditions of thermal fatigue upon filling with liquid metal. The samples are tested by cyclic heating in a furnace to maximum temperatures from 700 to 1000 degrees C with subsequent cooling in air and water. The dependences of the Coffin type and the crack growth rate in the samples are obtained on the basis of metallographic measurements of the crack depth in the samples and calculations by the finite element method of the deformation span. The results of the research allow us to predict the durability of casting molds made of SCh20 under conditions of thermal fatigue upon filling with liquid metal.