International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Metallurgy under pressure is one of the main trends in the development of quality metallurgy. High-nitrogen steel of responsible purpose for special engineering was created and produced on the basis of metallurgy under pressure by the methods of special electrometallurgy. Comparative mechanical tests of high-nitrogen steel were carried out. The structure of the steel was analyzed by the methods of non-destructive testing. High nitrogen steel was found to meet the technical requirements. The structure is dense, without defects.

The work is performed by analysing spiral welded joints Helical Submerged Arc Welding and their most common errors, which they occur during the submerged arc welding process and can be detected by non-destructive tests. Pipelines were made of structural alloy steel, hot-rolled. Welded defects were detected by X-ray method. A microstructural test was carried out to detect internal errors of the weld joint. Mechanical tests were used to determine the effect on change of properties. After detecting errors on the end X-ray, they were welds subsequently corrected. Destructive or non-destructive testing of gas pipeline welds has its justification, mainly for safety reason.

Mechanical tests of 5- and 6-component high-entropy alloys, which were obtained for the first time by the method of hot forging, were carried out. The test results showed a fairly high hardness and strength of the obtained alloys. The TiCrFeNiC alloy (without annealing) has the highest mechanical properties. Its high strength is due to solid-solution hardening, as well as the formation of carbides in situ. Fractographic studies showed mostly quasi-brittle destruction of alloy samples.