The impact of manufacturing strategies on the development of residual stresses in Dievar steel is presented. Two fabrication methods were investigated: conventional ingot casting and selective laser melting as an additive manufacturing process. Subsequently, plastic deformation in the form of hot rotary swaging at 900 °C was applied. Residual stresses were measured using neutron diffraction. Microstructural and phase analysis, precipitate characterization, and hardness measurement—carried out to complement the investigation—showed the microstructure improvement by rotary swaging. The study reveals that the manufacturing method has a significant effect on the distribution of residual stresses in the bars. The results showed that conventional ingot casting resulted in low levels of residual stresses (up to ±200 MPa), with an increase in hardness after rotary swaging from 172 HV1 to 613 HV1. SLM-manufactured bars developed tensile hoop and axial residual stresses in the vicinity of the surface and large compressive axial stresses (−600 MPa) in the core due to rapid cooling. The subsequent thermomechanical treatment via rotary swaging effectively reduced both the surface tensile (to approximately +200 MPa) and the core compressive residual stresses (to −300 MPa). Moreover, it resulted in a predominantly hydrostatic stress character and a reduction in von Mises stresses, offering relatively favorable residual stress characteristics and, therefore, a reduction in the risk of material failure. In addition to the significantly improved stress profile, rotary swaging contributed to a fine grain (3–5 µm instead of 10–15 µm for the conventional sample) and increased the hardness of the SLM samples from 560 HV1 to 606 HV1. These insights confirm the utility of rotary swaging as a post-processing technique that not only reduces residual stresses but also improves the microstructural and mechanical properties of additively manufactured components.

The presented work is focused on the influence of imposed strain on the weldability of Dievar alloy. Two mechanisms affecting the microstructure and thus imparting changes in the mechanical properties were applied—heat treatment (hardening and tempering), and rotary swaging. The processed workpieces were further subjected to welding with various welding currents. In order to characterize the effects of welding on the microstructure, especially in the heat-affected zone, and determine material stability under elevated temperatures, samples for uniaxial hot compression testing at temperatures from 600 to 900 °C, optical and scanning electron microscopy, and microhardness testing were taken. The testing revealed that, although the rotary swaged and heat-treated samples featured comparable microhardness, the strength of the swaged material was approximately twice as high as that of the heat-treated one—specifically 1350 MPa. Furthermore, it was found that the rotary swaged sample exhibited favorable welding behavior when compared to the heat-treated one, when the higher welding current was applied.

This study compares the hot deformation behavior of Inconel 718 superalloy manufactured by the conventional and 3D-printing technology. The effect of subsequent intensive plastic deformation on changes in deformation behavior is also investigated. Both the nickel superalloys prepared by the conventional and 3D-printing ways before and after post-processing by rotary swaging were subjected to uniaxial hot compression tests to characterize a corresponding deformation behavior (via flow stress response) at a temperature range of 900–1200 °C and a strain rate range of 0.1–100 s⁻¹. Slightly different results were obtained at lower strain rates and temperatures. It was further also observed the conventionally prepared specimen way unable to withstand deformation at a temperature of 1200 °C, whereas the specimen using the 3D-printing technology was able to withstand deformation at this temperature range. Microstructure analysis showed that the rotary swaging process applied to 3D printed had a significant effect on grain size refinement and microstructure development with compared to conventionally prepared specimen. The average grain size of the 3D-printed workpiece after rotary swaging process was less than 2 µm. Furthermore, with decreasing deformation temperature and increasing strain rate, the Vickers microhardness measurement showed an increasing microhardness. Subsequent intensive plastic deformation resulted in relatively slight increase in both the flow stress response and microhardness. Maximum values of flow stress response (approximately 710 MPa) and microhardness (approximately 420 HV) were achieved at a combination temperature of 900 °C and strain rate of 10 s⁻¹.

The article describes the renovation of repeatedly worn shearing tools working cold up to 200 °C. The material from which the cutting punch is made of carries the trade name CALDIE. It is delivered from the smelter in the condition after soft annealing and subsequently it is refined. A worn or damaged edge is chamfered and welded afterwards by technology of micro-TIG in pulse mode. To restore the geometry of the damaged edge is used an intermediate layer between the base material and the final hard layer the ferritic-austenitic wire Cronitex RC 220. Eventually, the final hard layer is welded to the intermediate layer, either Cronitex RC 60 or RC 63. After welding, the tool is machined to the required dimensions and then integrated back into production. The main goal was to evaluate the possibility of extending the life of cutting tools and reducing the implementation of already inefficient repairs. For assessment several destructive tests were performed - macrostructure, microstructure, microhardness measurement and EDS analysis.

The paper deals with the FEM (Finite Element Method) simulation of rotary swaging of Dievar alloy produced by additive manufacturing technology Selective Laser Melting and conventional process. Swaging was performed at a temperature of 900°C. True flow stress-strain curves were determined for 600°C–900°C and used to construct a Hensel-Spittel model for FEM simulation. The process parameters, i.e., stress, temperature, imposed strain, and force, were investigation during the rotary swaging process. Firstly, the stresses induced during rotary swaging and the resistance of the material to deformation were investigated. The amount and distribution of imposed strain in the cross-section can serve as a valuable indicator of the reduction in porosity and the texture evolution of the material. The simulation revealed the force required to swag the Dievar alloy. It also showed the evolution of temperature, which is important for phase transformation during solidification. Furthermore, microstructure evolution was observed before and then after rotary swaging. Dievar alloy is a critical material in the manufacture of dies for high-pressure die casting, forging tools, and other equipment subjected to high temperatures and mechanical loads. Understanding its viscoelastoplastic behavior under rotary swaging conditions is essential to optimize its performance in these demanding industrial applications.