The article presents the results of studies of deposited metal and welded joints made of high-strength alloy steels made by austenitic type powder wire with nitrogen developed by the authors. It has been found that the use of this wire makes it possible to increase the strength of the deposited metal by 20-30% while maintaining high plasticity. In the structure of the seam metal in the central part, after welding of high-strength alloy steel, an austenitic-ferritic structure with a delta-ferrite content of ~3 vol. is formed. % in accordance with the AF type crystallization mechanism, and a small amount of lower bainite is also present. The microhardness of the weld metal varies in the range HV0.1 200-250. As the distance from the center of the seam metal to the melting line increases, the structure transforms with an increase in the bainite content. At the melting line, the phase composition is a γ-phase in the amount of 44.7 vol. %, an α-phase in the amount of 51.8 vol. %, as well as carbides of the order of 0.5 vol.%. The structure on the melting line is represented by large grains of austenite in the central part and lower bainite, which has carbides in the volume of the α-phase, and δ-ferrite, the amount of which remains unchanged (3 vol. %). In the zone of thermal exposure, the length of which is 2-2.5 mm, a structure was formed, which is a mixture of lower bainite and brass martensite (the total content of the α-phase is 98.6 vol.%) with a microhardness of HV0.1 400-550. The use of austenitic grade powder wire with nitrogen for welding high-strength alloy steels makes it possible to obtain defect-free welded joints with an austenitic-ferritic structure.