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This research examines the technological processes of applying CrN coating on low-alloy tool steel, focusing on the comparison between hardening-tempering-coating (HTC) and hardening-coating (HC) processes, with an emphasis on energy savings. The study investigates the chemical composition, microstructure, mechanical properties, fractography, residual stress, and corrosion resistance of the coated tool steel. Notably, the results indicate no significant differences in the microstructural, mechanical, and corrosion properties between the HTC and HC processes, suggesting that tempering may be excluded without compromising the quality. This study introduces a novel approach to tool steel coating, which improves energy efficiency while maintaining high-quality outcomes. The findings highlight potential improvements in industrial applications, offering an energy-efficient alternative that does not sacrifice the performance or durability of the tool steel. This advancement could lead to significant improvements in manufacturing efficiency and sustainability.

The presented article familiarizes the reader with optimizing the workplaces of ultrasonic welding machines. The essential part of the article deals with prototypes, the construction of which does not meet the requirements for production, economy, and functionality. The experimental analysis runs pointed out shortcomings and inaccuracies. The developer’s team used one of the well-known optimization and design methods to solve this issue. It is the TRIZ method (Creating and solving creative assignments). The mentioned method combines two powerful tools into one whole. Specifically, it is the Function and Cost Analysis (FNA) and the algorithm for solving creative assignments (ARIZ). The manuscript describes the use of the method for a more straightforward solution to problematic parts of the structure. The result of the optimization process is a new, improved structure whose properties were confirmed in terms of stiffness by simulation in the ANSYS Workbench program. The applications of optimized parts will also be used in other similar devices. The research will follow up with the design of a new series of ultrasonic welding machines in the future.

Influence of shot peening on the wear behaviour of medium carbon, C55 steel was experimentally verified. Experimental work included determination of the chemical composition, heat treatment, microstructure evaluation, mechanical properties measurement, shot peening treatment, the magnitude of the compressive residual stresses was evaluated, roughness profiles measurement and finally the friction tests. The results evidence the significant role played by the applied shot peening on wear behaviour of medium carbon steel. An important effect of surface roughness has been demonstrated. The coefficient of friction after shot peening compared to ground surface increased, 1.44 – 1.85 times.

Due to wear and improper operation, many machine parts become useless, which is why issues of friction and wear remain constantly relevant across all industrial sectors. This paper presents the results of research on the microstructure and properties of a nanostructural composite coating containing solid lubricant. The coating was deposited from a mixture of nanostructural WC-12Co powder and nanostructural Fe3O4 powder using HVOF spraying. Despite significant differences in grain size and density of both powders, the deposited coating consisted of WC-12Co matrix containing evenly distributed Fe3O4. The XRD analysis of the coating confirmed the presence of both components and the presence of W2C, which resulted from the decarburization of WC due to the high temperature during the spraying process. Furthermore, the microstructure analysis of the coatings confirmed that they contained both nanostructural WC and Fe3O4 grains that were present in the feedstock. The coefficients of friction, microhardness, and wear of the nanostructured composite coatings were determined using an experimental binomial program. Based on the ANOVA conducted, it was determined that the most significant impact on the friction coefficient is the Fe3O4 content in the sprayed mixture, while the oxygen to propane ratio affects the microhardness. For the wear of nanostructural composite coatings, the most important parameter is the spraying distance. [ABSTRACT FROM AUTHOR]

The tribological properties of the nitride layer applied to the low-alloyed steel were investigated in this research. Experimental work included determination if the chemical composition, wear resistance, Rockwell, Vickers and nano-indentation tests, both of the substrate material – the low-alloyed steel and the deposited nitride layer. From the results obtained in those experiments authors concluded that applying the nitride layer does not significantly improve the tribological properties of the tested lowalloyed steel samples, thus this process is not recommended for achieving that purpose.

The article deals with a reduction of friction coefficient of bearing steel 100Cr6. Reduction of friction was achieved by means of a CarbonX DLC coating. The coating exhibited excellent friction and mechanical properties. This coating was applied to samples made of 100Cr6 bearing steel. The friction results of the CarbonX coating were compared to the friction results of the 100Cr6 bearing steel. Reducing the friction of 100Cr6 bearing steel resulted in reduced wear and increase lifetime. The friction process of the samples will take place in an environment without lubrication. The aim of the article is to verify the behaviour of the DLC coating without the presence of lubricant in the friction node. The achieved results are to be interpreted in the conclusion of article.

Results of experimental testing of the shot peened steel C55 specimens are presented in this paper. The aim was to establish behaviour of the compressive residual stresses induced by the shot peening at elevated temperatures; namely their stability in terms of temperature and time. Experimental work included verification of the tested material chemical composition, heat treatment (austenitization at 820 °C ± 5 °C for 30 minutes, cooling in the Durixol V70 oil at 20 °C ± 5 °C, high tempering at 450 °C ± 5 °C for 120 minutes, followed by cooling in air), tensile tests according to EN 10002-1 standard, hardness (HRC) measurements, shot peening with parameters Almen intensity 12A and coverage of 100 %, at the incidence angle close to 90° with respect to the specimen surface. The residual stresses state was evaluated by the X-ray diffraction measurement. It was concluded that the elevated temperature of 130 °C and after exposure of 100, 500 and 1000 hours, did not cause a significant decrease in compressive residual stresses. [ABSTRACT FROM AUTHOR]