In this study lath martensitic microstructure in S235JR and Mn-B alloyed steel sheets were produced. The Mn-B steel used as A and B pilar at autocars Laser welded blanks are an innovative way for automakers to reduce the weight of their vehicles while improving safety at the same time. We created welded joints with different parameters. Welding with 4100mm/min speed the weld metal hardness is similar to the late martensitic base material, and only a narrow heat affected zone is softened. Welding with lower speeds resulted softening of the weld metal and a double heat-affected zone: hard next to the weld metal and soft outside it.
High-performance handheld laser welding technologies have undergone significant advancements in recent years, particularly with the emergence of compact, cooled, and precise beam-shaping equipment. Handheld lasers (HL) possess all the advantages of their industrially applied, machine- or robotic-arm-guided counterparts. The key distinction lies in numerical beam control, which, alongside the parameters critical for successful welding, receives particular attention. This was due to the material- and penetration-depth-dependent program code table of the user-friendly Lightweld 1500 XT fiber laser welding equipment. During the experiments, S355 structural steel and DC01 cold-rolled steel sheets were welded in a T-joint configuration with varying sheet thicknesses, using identical material pairings. The used filler material was a Böhler EMK 8 Ø1 mm solid wire electrode, and the shielding gas was nitrogen with a 4.6. purity. We found that even with the settings recommended by the welding machine manufacturer, there were welding deviations, which suggests that the quality of manual welding also depends on the skill of the welder.
In our research, we investigated how the wear and corrosion resistance properties of ELMAX tool steel change during cryogenic treatment. The tool steel was heat treated in two different ways: con-ventionally, and using cryogenic treatment. From the two differently heat treated workpieces, 3 spe-cimens each were subjected to wear and corrosion tests. Based on the obtained results, it can be sta-ted that both the wear resistance and corrosion resistance improved as a result of the cryogenic tre-atment. These properties can clearly determine the usability of the material in many applications.
The aim of this study was to investigate the failure of titanium alloy fixation screws (connecting the implant and the abutment) used in custom-made subperiosteal implants. Once the cause of failure was determined, our main objective was to determine the maximum tightening torque for the existing design. To achieve this, 3D CAD screw models were examined using finite element software. Based on the results obtained, we were able to recommend a tightening torque interval to the screw manufacturer that was guaranteed not to lead to failure (provided that the screws are manufactured according to the dimensional tolerances specified in the drawing). Our secondary objective was to improve the design of the screw to ensure that the failure could be fully eliminated. In this paper we will describe the failure mode, its cause, the methodology of our investigation, the results obtained, the conclusions drawn and finally, future research opportunities.
Cooking oils play a crucial role in the food industry; however, during the cooking process, they undergo significant physical and chemical transformations that affect their subsequent usability and environmental impact. Our results show that oxidized rapeseed oil exhibits similar properties to industrial raw rapeseed oil, suggesting that used cooking oils at a certain oxidation state could potentially be suitable for surfactant synthesis. Since surfactants are widely used across various industries, this recycling approach offers a sustainable alternative to synthetic raw materials.
