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

The objective of this study is to develop a system for recording and processing acoustic emission signals. The research focuses on designing cost-effective experimental equipment for investigating acoustic emission processes under laboratory conditions, with the capability of being reconfigured for specific applications depending on loading conditions and methods, material properties, environmental conditions, etc. A laboratory rig for recording and analysing acoustic emission data has been developed and experimentally tested. This paper presents the system’s block diagram and its operational algorithm. Furthermore, the correlation between the results of statistical processing of the recorded data and the physical characteristics of the input signals is demonstrated using model acoustic signals, incorporating various components of the developed rig.

At present, various types of steel grades are used in the production of welded structures and assemblies, resp. combinations of ferrous and non-ferrous metals. In these mutual combinations, it is necessary to know the specifics of weldability of both materials, to choose a suitable welding technology and a suitable filler material. In the experimental part, the quality of heterogeneous welded joints was verified by the GMAW method. A protective gas atmosphere of 82% Ar + 18% CO2 was used for welding (M21 – ISO 14175: 2008). The possibilities of welding and mutual combinations of austenitic stainless steel with structural non-alloy steel, structural alloyed high-strength steel with structural non-alloy steel were assessed. The quality of welds was evaluated using non-destructive and destructive tests in terms of standards: visual test STN EN ISO 17637, capillary penetration test STN EN ISO 22476-12, internal errors were evaluated using radiation tests STN EN ISO 17636-1. The destructive tests used the tensile test STN EN ISO 6892-1, the weld fracture test STN EN ISO 5173 and the Vickers hardness test STN EN ISO 6507-1, the bending impact test STN EN ISO 9016 and the metallographic analysis according to STN EN ISO 17639.

New special high nitrogen steel used in arms industry is developed. The new steel and technology of its production are developed on the basis of the metallurgy under pressure. The mechanical properties by the results of the short -term strength and notchimpact strength tests are determined. The new steel has higher mechanical characteristics in comparison with conventional nitrogen free analogue. Non-destructive control is carried out. Dense structure without defects is established.

We have carried out researches for working out technological electroslag remelting conditions to produce bimetallic ingots. A new plant flow diagram has been developed for the manufacture. Experimental series of melting was performed on a laboratory electroslag remelting installation by developed by us electroslag remelting conditions. Bimetallic ingots for armour were produced of different combinations steel grades. Ingot of X38CrMoV 5 1 (DIN 1.2343; AISI H11) -10G2SF perspective steel grades is investigated. By the method of non-destructive testing the fusion of two steel grades along height of ingot is investigated. Macrostructure of cast transverse templates is investigated. A complete fusion of steels is established.