Springer Science and Business Media LLC

Metal of an experimental plate (workpiece) specially made of 15NiCuMoNb5 (WB36) steel, which imitates a full-scale fragment of a boiler drum, is studied. Chemical composition and microstructure are analyzed, and metal and welded joint hardness are determined taking account of the distribution of these characteristics over the plate thickness. It is shown that composition, structure and hardness of the base metal and welded joint depend weakly upon location of the zone studied within the plate thickness. Small distinctive features characterize only the metal of the heat-affected zone in the transition area from the main part to the root of the weld, due to a higher level of heat input in this area during welding.

Results of the use of automatic hydrogen-content meter for controlling the parameter of “hydrogen” in the primary coolant circuit of the Kola nuclear power plant are presented. It is shown that the correlation between the “hydrogen” parameter in the coolant and the “hydrazine” parameter in the makeup water can be used for controlling the water chemistry of the primary coolant system, which should make it possible to optimize the water chemistry at different power levels