Advanced reactor vessel steels for reactors with supercritical coolant parameters

Abstract

A set of studies, tests, and technological works is performed to design promising high-strength vessel steels for reactors with supercritical coolant parameters. Compositions and technological parameters are proposed for the production of reference steel (within the limits of the grade composition of 15Kh2NMFA-A steel) and high-nickel steel. These steels are characterized by high properties, including metallurgical quality and service and technological parameters. Steel of the reference composition has high (higher by 15%) strength properties, improved viscoplastic properties, and ductile–brittle transition temperature t_c of at most–125°C. The strength properties of the high-nickel steel are higher than those of the existing steels by 40–50% and higher than those of advanced foreign steels by 15–20% at ductile–brittle transition temperature t_c of at most–165°C. Moreover, the designed steels are characterized by a low content of harmful impurity elements and nonmetallic inclusions, a fine-grained structure, and a low susceptibility to thermal embrittlement.