Nizhny Novgorod State Technical University named after. R. E. Alekseev, Nizhny Novgorod, Russia
Yu. G. Kabaldin, Dr. Eng., Prof., Dept. of Technology and Equipment of Mechanical Engineering, Institute of Manufacturing Technologies in Machine Building
S. A. Sorokina, Cand. Eng., Associate Prof., Dept. of Materials Science, Materials Technologies and Heat Treatment of Metals, Institute of Physical and Chemical Technologies and Materials Science

Yu. S. Mordovina, Postgraduate Student, Engineer for the Educational Process of the Institute for Retraining of Specialists, Engineer of the Dept. of Technology and Equipment of Mechanical Engineering, Institute of Manufacturing Technologies in Machine Building

Nizhny Novgorod State Technical University named after. R. E. Alekseev, Nizhny Novgorod, Russia¹ ; Central Research Institute Burevestnik, Nizhny Novgorod, Russia²

M. A. Chernigin, Postgraduate Student, Engineer, Dept. of Technology and Equipment of Mechanical Engineering, Institute of Manufacturing Technologies in Machine Building¹, Research Engineer of the 3rd Category², e-mail: honeybadger52@yandex.ru

Nizhny Novgorod State Technical University named after. R. E. Alekseev, Nizhny Novgorod, Russia¹ ; RFNC – VNIIEF, Sarov, Russia²

S. V. Perova, Postgraduate Student, Dept. of Technology and Equipment of Mechanical Engineering, Institute of Manufacturing Technologies in Machine Building¹, Industrial Engineer²

Despite the fact that most products from austenitic steels are manufactured using cold plastic deformation (CPD) technologies, in the manufacture of products with complex configurations, the use of these technologies can be difficult, since the deformation of FCC metals at temperatures below recrystallization leads to a change in the structural-phase composition of the material and its physical and mechanical properties. Three-dimensional metal printing technologies make it possible to produce parts and structures of complex configurations using a minimum of shaping operations, almost completely eliminating the use of CPD. The behavior of the chemical composition of the starting material (wire) and the structure of metastable austenitic steel 07Kh25N13 during surfacing using the WAAM method and subsequent heat treatment is considered. It was revealed that when surfacing according to the used mode (I = 120 A, U = 24 V, V = 350 mm/min), the content of some alloying elements decreases, while the chemical composition of the steel does not exceed grade deviations. As a result of the study, it was established that during metal surfacing crystallization occurs according to the FA type with the formation of a coarse dendritic structure consisting of δ- and σ-phases. Post-surfacing austenitization at a temperature of 1070 °C practically does not change the structure. Increasing the temperature to 1100 °C leads to a decrease in the size of dendrites and the formation of austenite grains. On the milled surfaces of the samples, a more active formation of austenite grains occurs, which may be due to the occurrence of recrystallization processes during heating of the work-hardened metal. In this regard, it can be assumed that preliminary hardening and post-surfacing austenitization have a positive effect on the structure formation of the material after three-dimensional printing.

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