The transition to more environmentally friendly steel production methods has intensified research into hydrogen-based direct reduction (HyDR) of iron oxide pellets. aim this study is systematically investigate the kinetics process, evolution porosity and resulting microstructural changes on behavior high-quality pellets during HyDR ore at different temperatures. A modified mathematical model developed based shrinkage kernel model, taking account both mass heat transport in a hydrogen...

High grade pellets with basicity index close to 0.5 were directly reduced in pure hydrogen atmosphere. The reduction experiments performed the temperature range 800–1000 °C at pressure of 8 bar. internal structure was analysed through micro tomography observations unreduced and conditions. After reduction, showed a variation porosity up more than 15% remarkable change pore dimensions aspect. Given pores aspect variations, tortuosity strongly varied. This is believed have large influence on...

This paper presents a comprehensive study on the production and reduction of high-quality iron ore pellets characterized by basicity index nearing 0.5 diameters ranging from 1 to 2 cm. The process was carried out in hydrogen atmosphere at temperatures spanning 800–1000 °C pressure 8 bar. Initial findings revealed substantial variations pellet density compressive strength, attributed their mean dimensions. To delve into microstructural transformations occurring during reduction, meticulous...

This paper presents the hydrogen reduction behaviour of industrial pellets designed for efficient based direct reduction. The were provided with very low non ferrous oxides percentage (0.52 basicity index) and absence on TiO2 oxides. measured diameters in range 1.14–1.72 cm characterized terms porosity, pores size, tortuosity compression strength. reduced atmosphere a laboratory shaft furnace temperature ranges 600–1200 °C at pressures 1 5 bar. pellets' was analysed time to reduction, rate...

Abstract In response to the imperative for sustainable iron production with reduced CO 2 emissions, this study delves into intricate role of TiO in direct reduction oxide pellets. The -dependent reducibility pellets utilizing H and gas across varied temperatures compositions is thoroughly investigated. Our findings unveil nuanced nature effect, underscored by its concentration-dependent behavior, revealing an optimal range between 1 1.5 pct , where a neutral or positive impact on kinetics...

The aim of the work is to compare properties nanohydroxyapatite coatings obtained using electrophoretic deposition method (EDP) at 10 V, 20 and 30 with deposit times 2 5 min. primary sedimentation was used minimize risk formation particle agglomerates on sample surface. Evaluation coating performed by a Scanning Electron Microscope (SEM), Energy-Dispersive Spectroscopy (EDS), Atomic Force Microscopy (AFM), optical profilometer, drop shape analyzer, nanoscratch tester. All are homogeneous...

This paper focuses on comparing the three microscopic measurement techniques, confocal, focus variation, and point for focus, evaluation of entire fracture surface topographies. The measurements were performed using a Sensofar S Neox 3D optical profilometer Mitutoyo QV Apex 302 vision measuring system. test specimens required printed through laser powder bed fusion (LPBF) technology two materials: Stainless Steel 316L Inconel 718. printing was with power 200 W, scanning speed 800 mm/s, layer...

Aluminum alloys have been successfully used in the railroad and automotive industries because of their potential to significantly reduce component weights, good mechanical anti-corrosion properties. Problems with joining aluminum are characterized by low weldability, which influences need for studies focused on unconventional methods. The environmentally friendly low-cost friction-stir-welding method enables material be joined without melting. In following study, dissimilar butt joints were...

An aluminum matrix composite with dispersed carbon nanotubes (CNTs) was produced via flake powder metallurgy using a micro-rolling process and vacuum hot pressing (VHP), followed by conventional rolling macro-rolling process. The microstructure mechanical properties of the composites were studied. In addition, new quantitative model introduced to study dislocation density based on microstructural parameters. results revealed that distribution characteristics CNTs in Al Al-CNT interfaces two...

Abstract The friction stir welding process was simulated for joining AA6082 aluminum alloy with the use of computational fluid dynamics method. Two different tool geometries were used—a tapered cylindrical pin (simple pin) and a hexagonal grooves (complex pin). analysis simulations performed discussed in terms temperature evolution during process, total heat input, residual stresses material flow. Simulations revealed that 5% higher temperature, equal to maximum 406 °C, provided when using...

The friction stir welding method is increasingly attracting interest in the railway sector due to its environmental friendliness, low cost, and ease of producing high-quality joints. Using aluminum alloys reduces weight structures, increasing their payload reducing fuel consumption running costs. following paper presents studies on microstructure, strength, corrosion resistance AA6082 alloy sheets joined via welding. were by employing two different traverse speeds (200 250 mm/min),...

Abstract Carburization is a critical aspect in the iron and steel industry as it significantly affects mechanical chemical properties of final product. This study provides comprehensive analysis carburization potential high-grade quality ore pellets after direct reduction pure hydrogen. The results show that porosity has significant impact on efficiency success process with can be completed at lower temperature hydrogen compared to carbon monoxide, carbide concentration peaking temperatures...

The thermo-mechanical behavior of nanosized Al2O3 particles reinforcing aluminum was analyzed in the present paper. material prepared by spark plasma sintering and friction stir welding. thermal stresses affecting composite during welding were modeled through COMSOL MultiPhysics, results validated analyses composites’ mechanical properties. spark-plasma-sintered materials presented limited porosity, which taken into account modeling phase. Both model experiments revealed that higher heat...

Metallic materials intended for bone implants should exhibit not only appropriate mechanical properties, but also high biocompatibility. The surface treatment modifications, example acidic treatment, laser ion implantation and deposition of highly biocompatible coatings, are practiced. One the most popular methods surface modification is to deposit hydroxyapatite (HAp) coatings. HAp naturally occurs in human body, can be synthesized in laboratory conditions. Among diverse techniques,...

Abstract In the current study, biocorrosion resistance and mechanical properties of Ti–XAl–2Fe–3Cu (wt%) ( X = 6, 4, 2 wt%) alloy produced by powder compact extrusion blended elemental powders were optimized using response surface methodology in order to gain best combination processing parameters. To run optimization process, central composite design with three equal levels oxygen, hydrogen aluminum was used and, employing ANOVA, analysis variance implemented. The results showed that...

The rapid development of the building sector has created increased demand for novel materials and technologies, while on other hand resulting in generation a severe amount waste materials. Among these are polyurethane (PU) foams, which commonly applied as thermal insulation Their management is serious industrial problem, due to, example, their complex chemical composition. Although some thermochemical methods PU foam recycling known, broader use limited to requirements related complexity...

The article deals with the H 2 consumption for different processing conditions and composition of processed pellets during direct reduction process. experiments are carried out at 600–1300 °C, gas pressures 1–5 bar, flow rates L min −1 , basicity indices 0 to 2.15. Pellets compositions TiO Al O 3 CaO, SiO analyzed. rate is crucial, 0–10 leading an H2 0–5.1 kg /kg pellet. pressure (0–10 bar) increases from 5.1 Higher temperatures (600–1300 °C) reduce pellet, most efficiently 950–1050 where it...