NITRO-OXIDATION PRODUCTS FROM STRUCTURAL STEELS

The article examines the technology of nitro-oxidation, which consists of nitriding in separated ammonia at the first organize and oxidation in water vapor at the second stage of the process, studied the structure and phase composition of the diffusion nitride-oxide layer, providing high physico-mechanical and physicochemical surface characteristics, competitively capable of galvanic strategies of getting a coating, the conceivable outcomes of regulating the structure and phase composition of the nitride-oxide layer are being investigated to obtain a diffusion coating composition with predetermined properties.

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Structure and properties of the modified diffusion nitride-oxide surface layer

E3S Web of Conferences ◽

10.1051/e3sconf/202126405054 ◽

2021 ◽

Vol 264 ◽

pp. 05054

Author(s):

Kholikul Eshkabilov ◽

Sherzod Berdiyev

Keyword(s):

Surface Layer ◽

Water Vapor ◽

Oxide Layer ◽

Nitride Layer ◽

Phase Changes ◽

Oxide Surface ◽

Gas Nitriding ◽

Modified Surface ◽

Nitride Oxide ◽

Nitride Zone

To combine the processes of gas nitriding and oxidation in water vapor, the effects of the atmospheric nitrogen potential in dissociated ammonia on the formation of surface diffusion nitride phases are studied. Modification of the surface nitride layer with oxygen was carried out by oxidation of the nitride zone at the second stage of obtaining an oxycarbonitride layer. The corrosion and wear-resistant properties of the nitride-oxide layer t of the lowest nitride layer are investigated, depending on the phase changes in the nitride layer after oxidation. The distributions of the elements in the nitride-oxide layer are determined, and the nature of the formation of the modified surface layer under the combination of gas nitriding with subsequent oxidation in water vapor is established.

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Oxidation Behavior of Maraging 300 Alloy Exposed to Nitrogen/Water Vapor Atmosphere at 500 °C

Metals ◽

10.3390/met11071021 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1021

Author(s):

Mauro Andres Cerra Florez ◽

Gemma Fargas Ribas ◽

Jorge Luiz Cardoso ◽

Antonio Manuel Mateo García ◽

Joan Josep Roa Rovira ◽

...

Keyword(s):

Water Vapor ◽

Oxide Layer ◽

Magnetic Layer ◽

Adhesive Force ◽

Point Of View ◽

Maraging Steels ◽

Cobalt Spinel ◽

Water Vapor Atmosphere ◽

Iron Nickel ◽

Ferrite Cobalt

Aging heat treatments in maraging steels are fundamental to achieve the excellent mechanical properties required in several industries, i.e., nuclear, automotive, etc. In this research, samples of maraging 300 alloy were aged using a novel procedure that combines different steps with two atmospheres (nitrogen and water vapor) for several hours. The oxidized surface layer was chemical, microstructural and micromechanically characterized. Due to the thermodynamic and kinetic conditions, these gases reacted and change the surface chemistry of this steel producing a thin iron-based oxide layer of a homogeneous thickness of around 500 nm. Within the aforementioned information, porosity and other microstructural defects showed a non-homogeneous oxide, mainly constituted by magnetite, nickel ferrite, cobalt ferrite, and a small amount of hematite in the more external parts of the oxide layer. In this sense, from a chemical point of view, the heat treatment under specific atmosphere allows to induce a thin magnetic layer in a mixture of iron, nickel, and cobalt spinel ferrites. On the other hand, the oxide layer presents an adhesive force 99 mN value that shows the capability for being used for tribological applications under sliding contact tests.

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Effect of ammonium metavanadate on surface characteristics of oxide layer formed on Mg alloy via plasma electrolytic oxidation

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2013.08.060 ◽

2013 ◽

Vol 236 ◽

pp. 70-74 ◽

Cited By ~ 7

Author(s):

Young Gun Ko ◽

Kang Min Lee ◽

Dong Hyuk Shin

Keyword(s):

Oxide Layer ◽

Plasma Electrolytic Oxidation ◽

Surface Characteristics ◽

Ammonium Metavanadate ◽

Mg Alloy ◽

Electrolytic Oxidation ◽

Plasma Electrolytic

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Scanning 10-W Water Vapor DIAL for the Investigation of Atmospheric Turbulence and Land-Atmosphere Feedback

10.5194/egusphere-egu21-12925 ◽

2021 ◽

Author(s):

Andreas Behrendt ◽

Florian Spaeth ◽

Volker Wulfmeyer

Keyword(s):

Heat Flux ◽

Water Vapor ◽

Latent Heat ◽

Atmospheric Turbulence ◽

Latent Heat Flux ◽

Climate Models ◽

Weather Forecast ◽

Surface Characteristics ◽

Scanning System ◽

Forecast Models

We will present recent measurements made with the water vapor differential absorption lidar (DIAL) of University of Hohenheim (UHOH). This scanning system has been developed in recent years for the investigation of atmospheric turbulence and land-atmosphere feedback processes.The lidar is housed in a mobile trailer and participated in recent years in a number of national and international field campaigns. We will present examples of vertical pointing and scanning measurements, especially close to the canopy. The water vapor gradients in the surface layer are related to the latent heat flux. Thus, with such low-elevation scans, the latent heat flux distribution over different surface characteristics can be monitored, which is important to verify and improve both numerical weather forecast models and climate models.The transmitter of the UHOH DIAL consists of a diode-pumped Nd:YAG laser which pumps a Ti:sapphire laser. The output power of this laser is up to 10 W. Two injection seeders are used to switch pulse-to-pulse between the online and offline signals. These signals are then either directly sent into the atmosphere or coupled into a fiber and guided to a transmitting telescope which is attached to the scanner unit. The receiving telescope has a primary mirror with a dimeter of 80 cm. The backscatter signals are recorded shot to shot and are typically averaged over 0.1 to 1 s.

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Effect of water vapor on the surface characteristics and cell compatibility of zein films

Colloids and Surfaces B Biointerfaces ◽

10.1016/j.colsurfb.2008.11.015 ◽

2009 ◽

Vol 69 (1) ◽

pp. 109-115 ◽

Cited By ~ 27

Author(s):

Hua-Jie Wang ◽

Jian-Xi Fu ◽

Jin-Ye Wang

Keyword(s):

Water Vapor ◽

Surface Characteristics ◽

Cell Compatibility ◽

Effect Of Water

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A systematic assessment of water vapor products in the Arctic: from instantaneous measurements to monthly means

Atmospheric Measurement Techniques ◽

10.5194/amt-14-4829-2021 ◽

2021 ◽

Vol 14 (7) ◽

pp. 4829-4856

Author(s):

Susanne Crewell ◽

Kerstin Ebell ◽

Patrick Konjari ◽

Mario Mech ◽

Tatiana Nomokonova ◽

...

Keyword(s):

Water Vapor ◽

Surface Characterization ◽

Surface Characteristics ◽

The Arctic ◽

Monthly Means ◽

Atlantic Sector ◽

Mean Values ◽

Systematic Assessment ◽

Retrieval Algorithms ◽

Spatio Temporal

Abstract. Water vapor is an important component in the water and energy cycle of the Arctic. Especially in light of Arctic amplification, changes in water vapor are of high interest but are difficult to observe due to the data sparsity of the region. The ACLOUD/PASCAL campaigns performed in May/June 2017 in the Arctic North Atlantic sector offers the opportunity to investigate the quality of various satellite and reanalysis products. Compared to reference measurements at R/V Polarstern frozen into the ice (around 82∘ N, 10∘ E) and at Ny-Ålesund, the integrated water vapor (IWV) from Infrared Atmospheric Sounding Interferometer (IASI) L2PPFv6 shows the best performance among all satellite products. Using all radiosonde stations within the region indicates some differences that might relate to different radiosonde types used. Atmospheric river events can cause rapid IWV changes by more than a factor of 2 in the Arctic. Despite the relatively dense sampling by polar-orbiting satellites, daily means can deviate by up to 50 % due to strong spatio-temporal IWV variability. For monthly mean values, this weather-induced variability cancels out, but systematic differences dominate, which particularly appear over different surface types, e.g., ocean and sea ice. In the data-sparse central Arctic north of 84∘ N, strong differences of 30 % in IWV monthly means between satellite products occur in the month of June, which likely result from the difficulties in considering the complex and changing surface characteristics of the melting ice within the retrieval algorithms. There is hope that the detailed surface characterization performed as part of the recently finished Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) will foster the improvement of future retrieval algorithms.

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