Showing papers by "Andrej Atrens published in 2023"
TL;DR: In this paper , two-step plasma electrolytic oxidation (PEO) was implemented on Mg-Gd-Y-Zn alloy with long period stacking ordered (LPSO) phase in seven different electrolyte systems.
Abstract: In order to solve the problem of poor corrosion resistance of Mg-Gd-Y-Zn alloy with high strength and high toughness. In this paper, two-step plasma electrolytic oxidation (PEO) was implemented on Mg-Gd-Y-Zn alloy with long period stacking ordered (LPSO) phase in seven different electrolyte systems. Optical microscope (OM), Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) were used to characterize the structure distribution and composition of the LPSO phase. X-ray diffraction (XRD), SEM, EDS, Mott-Schottky test (M-S), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and immersion hydrogen evolution were used to study the morphology, composition, structure and corrosion resistance of the PEO coatings prepared using the various electrolytes. The PEO coating prepared by the mixed electrolyte of sodium aluminate, sodium phosphate and sodium silicate, referred to as PEO-APS coating, had the most excellent structure and corrosion resistance. The coating was dense and uniform, the coating thickness was 3.5 μm, the open porosity was 4.4 %, the average pore size was 0.12 μm, and the corrosion current density icorr was 2.09 × 10−8 A cm−2. In addition, the formation mechanism and corrosion resistance mechanism of the PEO-APS coating were discussed, and the effect of LPSO phase on the PEO-APS coating was proposed.
4 citations
TL;DR: In this paper , the authors provide an overview of hydrogen embrittlement in pipeline steels and the relationship between hydrogen pressure and absorbed hydrogen concentration has not been evaluated, and gaps in knowledge are identified in the conclusions.
Abstract: Abstract Hydrogen transport by blending hydrogen into natural gas transmission pipelines and by pure-hydrogen pipelines is a prospective mode of energy transmission during the transition to renewables. The risk of hydrogen embrittlement (HE) in pipeline steels must first be quantified to ensure safe pipeline operation. This review provides an overview of HE in pipeline steels. Most pipeline steels have reduced ductility when exposed to hydrogen partial pressures of 100 bar and above. Higher-strength pipeline steels (X80 and X100) have been found to undergo HE at ∼50 bar hydrogen. Hydrogen-induced subcritical crack growth in pipeline steels has not been reported in the literature. There are few articles on HE in pipeline welds, with some indications that the weld is more susceptible to HE, and some indications that it is less. The relationship between hydrogen pressure and absorbed hydrogen concentration has not been evaluated. Gaps in knowledge are identified in the conclusions.
1 citations
TL;DR: The effect of Cu alloying on hydrogen embrittlement in TWIP steel was studied using the low-speed linearly increasing stress test (LIST) with simultaneous cathodic hydrogen charging as mentioned in this paper .
TL;DR: In this article , the edge-to-edge matching model was used to identify TiB2 as a potential grain refiner to refine the high temperature δ-ferrite in low carbon steels.
01 Aug 2023-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article , a cost-effective Fe35Ni35Cr20Mo5Al5 HEA with ultrafine microstructure (UFM), including ultrafine grains (∼693 nm), high density of annealing twins and nanoprecipitates, was presented.
Abstract: Industry applications of the current cryogenic high entropy alloys (HEAs) are limited by their prohibitive costs, relatively low yield strength and unknown corrosion resistance. Here, we present a cost-effective and facile approach to produce cryogenic HEAs with lower cost, exceptional mechanical properties and corrosion resistance. The key is to design a cost-effective Fe35Ni35Cr20Mo5Al5 HEA and introduce ultrafine microstructure (UFM), including ultrafine grains (∼693 nm), high density of annealing twins and nanoprecipitates, into the alloy by manipulating the concurrent precipitation and recrystallization at 940 °C within 2 min. The cost-effective UFM-HEA exhibits a temperature-dependent strain-hardening capacity and a superior strength-ductility synergy at 77 K with a yield strength of ∼1165 MPa, a tensile strength of ∼1412 MPa and a uniform elongation over 20%. The superior tensile properties at cryogenic temperature are attributed to the twining-dominated multiple deformation mechanisms and the integrated strengthening effects, including grain refinement strengthening, twin strengthening and second-phase strengthening. At the fracture strain of ∼20%, extensive microcracks formed within the nanoprecipitates without propagating into the face-cantered-cubic matrix, suggesting a high crack tolerance of the UFM-HEA at both room and cryogenic temperatures. Moreover, the UFM-HEA has a superior corrosion resistance compared to the 316L stainless steel due to the larger passivity region and higher charge transfer resistance. Such outstanding cryogenic mechanical properties and corrosion resistance together with the lower cost make the UFM-HEA superior to most cryogenic HEAs. This strategy not only sheds light on the development of new-generation cryogenic HEAs but also significantly enhances their industrial application potential.