LOW THERMAL EXPANSION CAST STEEL AND METHOD FOR PRODUCING THE SAME

摘要

Obtained is a cast steel product with low thermal expansion. The cast steel product with low thermal expansion is characterized wherein the composition comprises: 0.04 mass% or less of C; 0.03 mass% or less of Si; 0.5 mass% or less of Mn; 0.2 mass% or less of Al; 31-34 mass% of Ni; 2-6 mass% of Co; and the rest consisting of Fe and unavoidable impurities, and the average crystal grain size of an austenite structure is equal to or less than 200 μm, and the thermal expansion coefficient is equal to or less than 0.2×10^-6/°C in a range of 18-28°C.