The main requirement for powders for additive 3d technologies is the spherical shape of the particles. Such particles are most compactly packed into a certain volume and ensure the "fluidity" of the powder composition in the supply systems of the material with minimal resistance. The wide use of the EED method for processing metal waste into powders for the purpose of their reuse and application in additive technologies is hampered by the lack in the scientific and technical literature of full-fledged information on the effect of the initial composition, regimes and media on the properties of powders and technologies of practical application. Therefore, in order to develop technologies for the reuse of electroerosive powders and to evaluate the effectiveness of their use, complex theoretical and experimental studies are required. The aim of the work was to conduct a phase analysis of additive products from electroerosive cobalt-chrome powders. The phase composition of the samples was studied by X-ray diffraction on a Rigaku Ultima IV diffractometer in Cu-Kα radiation (wavelength λ = 0.154178 nm) using Soller slits. Based on the results of the X-ray diffraction analysis of additive articles from electroerosion cobalt-chrome powders, it has been experimentally established that the main phases in the sintered samples are Co, Cr and Co3C.

The hydrostatic re-testing of pipelines is one of the general methods of determination of service reliability of pipes in the zones characterized by high risk of stress corrosion. The detailed complex metal-physics studies of structural and stress-strain state of steel, as well as topography of stress-corrosion cracks, hydrogenation in fragments of pipes damaged at various stages of loading during re-testing were carried out due to the idea of “damage” of steel caused by harmful effect of increased pipes deformation. Templates of pipes having fractures and zones with or without stress-corrosion defects were cut out for studies. It has been shown that no deterioration of mechanical and ductility properties occurs in the parts of pipes without stress-corrosion defects. No considerable changes of character and degree of cracking as well as cracks topography have been detected during various stages of re-testing.