Heat resisting steel for WWER reactor vessels and evaluation of its performance

Properties of 15KhZMFA steel employed for vessels of WWER type power plants are considered. The effect is shown of alloying elements on heat resistance, weldability, brittleness and radiation resistance of the steel. Impact viscosity and fatigue tests were carried out upon the samples being irradiated by a neutron flux of density (1-1.5)x1020 neut./cm-2 at 280-350 deg C. The 15KhZMFA steel proved to meet all the requirements to the materials for welded vessels of power plants and to have better mechanical properties and radiation resistance than the low alloyed steels used in the USSR and abroad for power plants construction