Thermal properties and structure of cast carbon-containing invar and superinvar alloys after two-stage annealing

The effect of carbon content on thermal properties of cast superinvar alloys subjected to two-stage annealing is studied. It is shown that carbon improves the casting properties of the alloys but raises the temperature coefficient of linear expansion (CTLE). Two-stage high-temperature annealing makes it possible to remove carbon from the solid solution and to transfer it into graphite, which is accompanied by decrease in the CTLE.