In connection with the growing importance of the efficiency and reliability of tools in industrial sectors, our research represents a key step in the effort to optimize production processes and increase their service life in real conditions. The study deals with the comparison of the tribological properties of three tool steels, two of which were produced by the powder metallurgy method—ASP2017 and ASP2055—and the last tool steel underwent the conventional production method—X153CrMoV12. The samples were mechanically machined with the finishing technology of turning and, finally, heat treated (Q + T). The study focused on the evaluation of hardness, resulting microstructure, wear resistance, and coefficient of friction (COF). The ball-on-disc method was chosen as part of the COF and wear resistance test. The tribological test took place at room temperature with dry friction to accelerate surface wear. The pressing material was a hardened steel ball G40 (DIN 100Cr6). Measurements were performed at loads of 10 N, 6 N, and 2 N and turning radii of 13 mm, 18 mm, and 23 mm, which represents a peripheral speed of 0.34, 0.47, and 0.60 m/s. The duration of the measurement for each sample was 20 min. The results showed that the COF of powder steels showed almost the same values, while a significant difference occurred with the increase of the radius rotation in the case of conventional steel. The results within the friction mechanism showed two types of wear, namely, adhesive and abrasive wear, depending on the Q + T process. From a tribological point of view in terms of wear, it was possible to state that the material ASP2055 after Q + T showed the lowest rate of wear of all the tested steels.

Friction stir welding (FSW) is a solid-state welding process that uses a rotating tool to soften and stir the base metal, thereby joining it. A special type of tool that has attracted the interest of researchers is the so-called bobbin tool (BTFSW), which, unlike conventional tools with one shoulder, features two shoulders that envelop the base metal from both the top and bottom sides. As a result, significant tensile stresses develop on both sides of the weld, caused by the action of both tool shoulders. In this paper, this issue was addressed by applying laser shock peening (LSP), aiming to introduce compressive stresses, which can be useful as a post-processing technique for BTFSW on both weld sides. It was found that this process completely alters residual stresses in the treated area, from tensile to compressive, through shock waves that impart plastic deformation in the surface layer. It was shown that the LSP effect is more pronounced as the accumulated energy is higher. As a consequence, the microhardness values were significantly increased in the surface and subsurface layers, reaching a maximum depth of 480 to 780 µm for the lowest and highest accumulated laser energy, respectively, while surface roughness increased. While increasing compressive stresses and microhardness in the surface layer is beneficial from the point of view of fatigue resistance, increased roughness has a detrimental effect. Accumulated energy was hereby shown to have a higher effect compared to the maximal energy applied to the specimens.

This article deals with the analysis of selected structural components of the HSS powder metallurgy steel ASP 2017 and ASP 2055 by quasi-static nanoindentation analysis. The microstructure and nanomechanical properties (reduced modulus of elasticity, nanohardness) of base material are analysed. The selected structural components based on the analysis of microstructure were investigated by the nanoindentation. The purpose was to describe basic condition of the structure and local nanomechanical properties of tested materials. Obtained results will serve as basic values for comparing the properties of modified states of those steels. Triboindenter Hysitron TI950 Triboindenter was used for research by using nanoindentation and built-in microscopy. Indentation tip with Berkovich geometry eas used for the experiment. The measured data were then analysed and evaluated by the Triboscan evaluation software.

This study evaluates the effect of different precipitation-hardening regimes on the microstructure, hardness, and tribological behaviour of W720 maraging steel. Experimental specimens were aged at temperatures ranging from 460 to 490 °C for 3–16 h following solution annealing. Tribological tests were performed using the Ball-on-Flat method under dry sliding conditions against a G40 steel ball. The worn surfaces were analysed using LSCM, SEM, and EDS. Aging increased the hardness from 323 HV1 to 580–606 HV1 and reduced the coefficient of friction from approximately 0.75 to 0.63–0.71. The lowest nominal specimen wear volume was measured for the as-received, solution-annealed W720 condition (0.011 mm³), followed by HT490_6 (0.012 mm³); these values were compared descriptively without inferential statistical testing. However, the reference specimen produced a narrow, locally deepest wear track and caused the highest wear of the counter-body. The highest wear volume of the specimen was recorded for HT480_3 (0.027 mm³), while HT460_8x2 combined the highest hardness and the lowest coefficient of friction with a high wear volume. The dominant wear mechanism was a combination of abrasive grooving, adhesive damage, and tribo-oxidation. The results demonstrated that the tribological resistance of W720 is not governed by hardness alone, but rather by the interplay between microstructure, wear-track geometry, wear-product morphology, and the distribution of wear between the specimen and the counter-body.