scholarly journals Numerical investigation of melting and solidification processes in modified surface layers of metal at induction heating

2017 ◽  
Author(s):  
V. G. Shchukin ◽  
V. N. Popov
Keyword(s):  
Numerical Investigation ◽  
Induction Heating ◽  
Surface Layers ◽  
Solidification Processes ◽  
Modified Surface ◽  
Melting And Solidification

scholarly journals Surface Modification of a Nickel-Free Austenitic Stainless Steel by Low-Temperature Nitriding

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1845
Author(s):  
Francesca Borgioli ◽  
Emanuele Galvanetto ◽  
Tiberio Bacci
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Low Temperature ◽  
Stainless Steels ◽  
Volume Fraction ◽  
Surface Hardness ◽  
Austenitic Stainless Steels ◽  
Surface Layers ◽  
Modified Surface

Low-temperature nitriding allows to improve surface hardening of austenitic stainless steels, maintaining or even increasing their corrosion resistance. The treatment conditions to be used in order to avoid the precipitation of large amounts of nitrides are strictly related to alloy composition. When nickel is substituted by manganese as an austenite forming element, the production of nitride-free modified surface layers becomes a challenge, since manganese is a nitride forming element while nickel is not. In this study, the effects of nitriding conditions on the characteristics of the modified surface layers obtained on an austenitic stainless steel having a high manganese content and a negligible nickel one, a so-called nickel-free austenitic stainless steel, were investigated. Microstructure, phase composition, surface microhardness, and corrosion behavior in 5% NaCl were evaluated. The obtained results suggest that the precipitation of a large volume fraction of nitrides can be avoided using treatment temperatures lower than those usually employed for nickel-containing austenitic stainless steels. Nitriding at 360 and 380 °C for duration up to 5 h allows to produce modified surface layers, consisting mainly of the so-called expanded austenite or gN, which increase surface hardness in comparison with the untreated steel. Using selected conditions, corrosion resistance can also be significantly improved.

scholarly journals Effect of Preliminary Irradiation of 321 Steel Substrates with High-Intense Pulsed Ion Beams on Scratch Test Results of Subsequently Deposited AlN Coatings

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1169
Author(s):  
Vladislav Tarbokov ◽  
Sergey Pavlov ◽  
Egor Smolyanskiy ◽  
Vladimir Uglov ◽  
Mikhail Slobodyan ◽  
...  
Keyword(s):  
Ion Beam ◽  
Energy Levels ◽  
Scratch Test ◽  
Future Research ◽  
Surface Layers ◽  
Emission Signal ◽  
Future Research Directions ◽  
Modified Surface ◽  
Scratch Tests ◽  
Steel Substrates

The paper presents the effect of irradiation of 321 steel substrates with a high-intense pulsed ion beam (HIPIB) on changes in functional properties of the surface layers and tribological characteristics of AlN coatings subsequently deposited above by the reactive magnetron sputtering method. The morphology of the modified surface layers, their microhardness and free surface energy levels are presented for different HIPIB energy densities. HIPIB irradiation of the substrates caused variations in the results of scratch tests combined with the acoustic emission signal processing. Their analysis has enabled concluding that the crack initiation threshold could be at least doubled for the studied coating/substrate system due to preliminary HIPIB irradiation. Finally, the obtained data were discussed, and future research directions were proposed.

scholarly journals Heat transfer study of poly-c PV system integrated with phase change material under semi-arid area (Errachidia-Drâa Tafilalet)

2021 ◽  
Vol 297 ◽  
pp. 01008
Author(s):  
Ibtissam Lamaamar ◽  
Amine Tilioua ◽  
Zaineb Benzaid ◽  
Abdelouahed Ait Msaad ◽  
Moulay Ahmed Hamdi Alaoui
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Operating Temperature ◽  
Pv System ◽  
Pv Module ◽  
Solidification Processes ◽  
Change Material ◽  
Transfer Study ◽  
Melting And Solidification

The high operating temperature of the photovoltaic (PV) modules decreases significantly its efficiency. The integration of phase change material (PCM) is one of the feasible techniques for reducing the operating temperature of the PV module. A numerical simulation of the PV module with PCM and without PCM has been realized. The thermal behavior of the PV module was evaluated at the melting and solidification processes of PCM. The results show that the integration of RT35HC PCM with a thickness of 4 cm reduces the temperature of the PV module by 8 °C compared to the reference module. Compared the RT35 and RT35HC, we found that the latent heat has a significant effect on the PCM thermal comportment. Furthermore, it has been found that the thermal resistance of the layers plays an important role to dissipate the heat from the PV cells to the PCM layer, consequently improving the heat transfer inside the PV/PCM system.

Modeling Of The Alloying Substances Distribution In The Melt During Pulsed Induction Heating Of The Substrate

2017 ◽  
Vol 12 (2) ◽  
pp. 111-118
Author(s):  
Vladimir Popov
Keyword(s):  
Induction Heating ◽  
Stokes Equations ◽  
Substrate Surface ◽  
Boussinesq Approximation ◽  
Navier Stokes ◽  
Empirical Formulas ◽  
Metal Solidification ◽  
Navier Stokes Equations ◽  
High Frequency Electromagnetic Field ◽  
Melting And Solidification

Under study is the applicability of the high-frequency electromagnetic field impulse for metal heating and melting with a view to its subsequent alloying. The processes of heating, phase transition, heat and mass transfer in the molten metal, solidification of the melt are considered with the aid the proposed mathematical model. The substrate surface is covered with a layer of alloying substances. The distribution of the electromagnetic energy in the metal is described by empirical formulas. Melting and solidification of the metal is considered at the Stephan’s approximation. The flow in the liquid is described by the Navier – Stokes equations in the Boussinesq approximation. According to the results of numerical experiments, the flow structure in the melt and distribution of the alloying substances was evaluated versus the characteristics of induction heating

Properties of modified surface layers of industrial steel samples processed by pulsed plasma streams

Vacuum ◽  
2000 ◽  
Vol 58 (2-3) ◽  
pp. 195-201 ◽  
Author(s):  
I.E. Garkusha ◽  
O.V. Byrka ◽  
V.V. Chebotarev ◽  
N.T. Derepovski ◽  
G. Müller ◽  
...  
Keyword(s):  
Pulsed Plasma ◽  
Surface Layers ◽  
Modified Surface

Numerical investigation of the transport phenomena occurring in the growth of SiC by the induction heating TSSG method

2017 ◽  
Vol 474 ◽  
pp. 50-54 ◽  
Author(s):  
Takuya Yamamoto ◽  
Nikhil Adkar ◽  
Yasunori Okano ◽  
Toru Ujihara ◽  
Sadik Dost
Keyword(s):  
Numerical Investigation ◽  
Induction Heating ◽  
Transport Phenomena

scholarly journals Characterization of the Surface Layer of Mg Enriched with Al and Si by Thermochemical Treatment

2017 ◽  
Vol 17 (4) ◽  
pp. 195-199 ◽  
Author(s):  
R. Mola ◽  
E. Stępień ◽  
M. Cieślik
Keyword(s):  
Solid Solution ◽  
Thermochemical Treatment ◽  
Heating Time ◽  
Substrate Material ◽  
Surface Layers ◽  
X Ray ◽  
Three Phase ◽  
Distribution Of Elements ◽  
Modified Surface

AbstractThe modified surface layers of Mg enriched with Al and Si were fabricated by thermochemical treatment. The substrate material in contact with an Al + 20 wt.% Si powder mixture was heated to 445°C for 40 or 60 min. The microstructure of the layers was examined by OM and SEM. The chemical composition of the layer and the distribution of elements were determined by energy dispersive X-ray spectroscopy (EDS). The experimental results show that the thickness of the layer is dependent on the heating time. A much thicker layer (1 mm) was obtained when the heating time was 60 min than when it was 40 min (600 μm). Both layers had a non-homogeneous structure. In the area closest to the Mg substrate, a thin zone of a solid solution of Al in Mg was detected. It was followed by a eutectic with Mg17Al12and a solid solution of Al in Mg. The next zone was a eutectic with agglomerates of Mg2Si phase particles; this three-phase structure was the thickest. Finally, the area closest to the surface was characterized by dendrites of the Mg17Al12phase. The microhardness of the modified layer increased to 121-236 HV as compared with 33-35 HV reported for the Mg substrate.

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