The VVER core baffle is one of the main elements of the reactor internals and serves to protect the reactor vessel from neutron irradiation. The material of the VVER core baffle experiences the greatest radiation loads and has the maximum temperature due to γ-heating as a result of irradiation. Neutron irradiation leads to radiation swelling, reduction of plasticity and crack resistance of the material. Steel grade 08H18N10T is used for the production of forged rings for the internal elements of the VVER-1000 nuclear reactor. This steel is guaranteed to ensure the performance of this element and its structural integrity during the entire service life, but the new generation VVER has a larger damaging dose of neutrons falling on the material of the core baffle. Designed service life, in such conditions, is achievable to ensure by currently developed new austenitic steel with increased resistance to radiation swelling and embrittlement. An additional requirement for the material of the core baffle is a given grain size -not larger than G3 according to GOST 5639. Grinding the grain size in austenitic steel is possible only at the stage of hot plastic deformation of the workpiece (forging). The final technological operation, in which the formation of the structure and properties of the metal occurs, is heat treatment, in which the forged rings of the core baffle are heated to a high temperature, followed by cooling in water (hardening without polymorphic transformation). The temperature and duration of heating for quenching should ensure the production of homogeneous austenite in the absence of enlargement of the grain structure formed by forging. This article presents a comparative assessment of the effect of exposure temperature and duration on the complex of mechanical properties and the tendency to grain growth of new austenitic steel and used steel 08H18N10T, as well as determining the optimal parameters of heating and holding for quenching of forged ring from new steel for the core baffle.