Steel having resistance to embrittlement by neutron irradiation - contg. small amts. of copper, tin and antimony

摘要

The steel contains by wt. 0.12-0.2%C, 0.15-0.37% Si, 0.3-0.8% Mm, 1.6-2.7% Cr, 0.8-2% Ni, 0.5-1% Mo. 0.05-0.15% V, 0.002-0.08% Ce, 0.01-0.1% Cu, 0.0005-0.009% Sb, 0.0005-0.009% Sn, 0.001-0.02% S, 0.002-0.02% P, 96.246-92.862% Fe. The steel is suitable for structural components having a wall thickness up to 650 mm. It is resistant to neutron inadiation. At 300 degrees C and a neutron flux of 1 x 1020 neutrons/cm2 (E 0.5 MeV) the transition embrittlement temp. increases by is not 50 degrees C. Mechanical properties typical of the steel are (at 20 degrees C), YS 55kg/mm2, V.T.S 62 kg/mm2, elongation =15% and redn. of area =55 degrees. Corresponding values at 350 degrees C are YS =45 kg/mm2, VTS =55 kg/mm2, elongation 14% and redn of area =50%. The steel does not require immediate tempering after welding.