Provided is a material for brake discs that has temper softening resistance sufficient to maintain a hardness of HRC 31 or more after tempering at 700°C for one hour. Specifically, a low-carbon martensitic chromium-containing steel contains 0.02% to 0.10% of carbon and 0.02% to 0.10% of nitrogen, the total content of carbon and nitrogen being 0.08% to 0.16%; 0.5% or less of silicon; 0.1% or less of aluminum; 0.3% to 3.0% of manganese; 10.5% to 13.5% of chromium; 0.05% to 0.60% of niobium and 0.15% to 0.80% of vanadium, the total content of niobium and vanadium being 0.25% to 0.95%; 0.02% to 2.0% of nickel; and 1.5% or less of copper, and has an Fp value (= -230C + 5Si - 5Mn - 6Cu + 10Cr - 12Ni + 32Nb + 22V + 12Mo + 8W + 10Ta + 40A1 - 220N) of 80.0 to 96.0, a hardness after quenching of HRC 31 to 40, and a hardness after tempering at 700°C for one hour of HRC 31 or more.
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