Abstract: The invention relates to a high alloy iron that has an austenitic structure and a spherical graphite configuration and comprises the following components in percent by weight: carbon<2.0%, silicon 2.0-6.0%, nickel 29-36%, chrome 1.0-2.5%, niobium 0.1-1.0% and molybdenum 0.1-2.5%. The invention also relates to the use of the cast iron material for structural components that are subject to high thermal stress, especially for exhaust manifolds and turbocharger housings of internal combustion engines of the individual or integrated type of construction. The invention finally relates to a structural component that is subject to high thermal stress, especially the exhaust system of an engine consisting of the aforementioned cast iron material.