Austenitic cast iron with a low nickel content - for reinforcing aluminium pistons for IC engines

摘要

In the parent patent is disclosed an austenitic cast iron which has a low Ni content and a coefft. of thermal expansion of 16.0 x 10-6 to 21.0 x 10-6 per degree between 20 and 100 degrees C. and wear and strength properties corresponding to GGL NiCuCr 15 6 2. The range of Ni content of the cast iron is now widened without having an adverse effect on these properties. The cast iron has the compsn. 6.0-8.0% Ni, 1.5-4.0% C, 0.5-4.0% Si, 4.0.14.0% Mn, 0.3-7.0% Cu, 2.0% Cr, 0.3-8.0% Al, 0.01-0.5% Ti, balance Fe and usual impurities. A wider range in Ni content facilitates prodn. of the cast iron while the saving in costs as a result of a low Ni content is not adversely affected. The cast iron is used for reinforcing annular slots in Al pistons in internal combustion engines.