This paper presents an analysis of the wear of the surface layer of drawing dies after the steel wire drawing process. It was shown that the working surface of the drawing die is characterized by high roughness combined with the occurrence of numerous scratches and blurs. As a result of high pressures in the deformation zone, premature wear of drawing dies combined with mechanical damage and the sticking of steel on the drawing surfaces can occur during the industrial drawing process. The finite element method analysis showed a significant relationship between the friction coefficient and the rate of drawing die wear. The varying distribution of stresses in the drawing die during the drawing process can contribute to mechanical damage. Longitudinal tensile stresses at the wire’s entrance to the drawing die increase the risk of circumferential cracking of drawing dies.

The article contains results of research and analyses concerning application of nanostructured bainitic steel in the form of plates for manufacturing of armour components. The presented results of examination of microstructure and properties include a wide range of laboratory experiments and industrial tests, which resulted in the achievement of the assumed functional properties. In the period of 2017-2021, a scientific and industrial consortium consisting of Łukasiewicz – Institute of Ferrous Metallurgy (leader); WITPiS, Tarnów Mechanical Works, Alchemia and Heatmasters Poland carried out a project funded by the POIR 04.01.04 programme aimed to develop the design and to manufacture an observation and protective container with a specified resistance to penetration by armour-piercing projectiles and with a lower mass of steel armouring in relation to that currently produced. The aim of the project was achieved by using armour plates made of nanostructured bainitic steel (nanobainitic), which are characterised by high resistance to high-energy impact concentrated in a small area. The technological tests carried out in the project mainly concerned the development of a new container and industrial technology of armour plates production and their application in the armour of this container. Based on the results of investigation of the semi-industrial scale material, the optimum chemical composition for industrial scale melting and casting was determined. An industrial technology for the production of plates of nano-structured bainitic steel was developed, which includes the following processes: smelting and casting, preliminary heat treatment and ingot hot processing, as well as hot rolling, final heat treatment, and surface treatment. A test batch of the material in the form of 1500×2470 mm armoured plates was fabricated under industrial conditions. The final result of the project is a container armoured with bainitic nanostructured steel plates with implementation documentation and a technology for producing armoured plates from this steel under the technical and technological conditions of domestic steel manufacturers.

The paper presents the results of investigation of the microstructure and mechanical properties of Fe-based materials designed for the manufacture of semi-spherical liners for experimental shaped charges. The tests were carried out on material samples taken from two semi-finished products, i.e. a rod for the manufacture of charge liners with a diameter of 50 mm using machining, and sheets for the manufacture of liners with a diameter of 100 mm using cold drawing. Microstructure examination was also carried out on a test specimen obtained using the additive method (3D-WAAM), made of low-carbon unalloyed steel wire. Firing tests on concrete blocks were carried out in order to quantify the effects of drilling at the Experimental Mine Barbara. The scope of the tests consisted of firing at cylindrical concrete blocks using projectiles containing 50 mm diameter liners made of Fe-based alloys. Based on the results of the laboratory material, two experimental steel grades were selected for further testing. Plates made of the selected steels will be used to manufacture charge liners with a diameter of 100 mm.

The article presents the results of investigation of the microstructure and mechanical properties of Fe-based materials intended for the production of semi-spherical liners for experimental shaped charges. The tests were carried out on samples taken in three directions in relation to the rolling direction: 0°, 45° and 90°, of the following materials: cold-rolled sheets made of DC04 steel, hot-rolled sheets made of 04J steel, and cold-rolled strips made of 004G steel developed at Łukasiewicz – IMŻ and annealed at 650°C. Semi-spherical drawpieces with a diameter of 106.4 mm, intended for liners, were made of the sheets with the use of cold stamping. Tests of the microstructure and HV hardness of samples taken from the test batch were carried out on cross-sections along the pressing direction and the model batch – on sections transverse to the stamping direction The geometry of the model batch drawpieces was also measured. The ferrite grain size evaluation was performed according to the ASTM E112 standard using μgrain software with a grain size evaluation module using counting the number of intersections of grain boundaries with a circle.

The article presents the results of controlled cooling experiments after austenitising a V36 section made of structural steel S480W. The experiments involved variable cooling intensity affecting the cross-section of the test element. The tests aimed to investigate the possibility of modifying the microstructure and uniformly increasing the mechanical properties of steel sections with varied cross-sectional wall thickness in relation to free-air cooling. The research work involved the determination of section-related cooling characteristics identified using various parameters of compressed air blown from nozzles onto selected surfaces of the section. The accelerated cooling tests led to the formation of a fine ferritic-pearlitic microstructure having ferrite grain size Dα restricted within the range of 6.8 μm to 6.5 μm. In addition, the tests resulted in the obtainment of uniform hardness distribution in cross-section, an increase in yield point Re and tensile strength Rm (restricted within the range of approximately 40 MPa to 60 MPa) while maintaining similar elongation.