scholarly journals Activation of diffusion during the formation of boride layers on the surface of steel parts

2021 ◽  
pp. 94-99
Author(s):  
S. M. Usherenko ◽  
V. G. Dashkevich ◽  
Yu. S. Usherenko
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Surface Activation ◽  
Powder Composition ◽  
Diffusion Layers ◽  
Superdeep Penetration ◽  
Quantitative Characteristics ◽  
Diffusion Boriding ◽  
High Boron ◽  
Preliminary Activation

The features of structure formation of diffusion layers obtained by the technology, including preliminary surface treatment of steel products and subsequent thermal diffusion boriding in powder media, have been investigated. Pretreatment consisted in surface activation by superdeep penetration with a powder composition based on SiC of steel samples made of У8 steel. The features of the activation zones and their distribution over the surface are noted. The features of the activation zones and their quantitative characteristics are noted. A structural analysis of the obtained diffusion layers for the variants of low-temperature (650 °C) and high-temperature (920 °C) boration has been carried out. The chemical composition of the layer and the distribution of the main elements in it are analyzed. In both cases, a change in morphology was noted, consisting in the formation of a more compact diffusion layer and rounding of boride needles in the zone adjacent to the base metal. An increase in the layer thickness by 20–50 % and an increase in the proportion of the high-boron FeB phase relative to the variant of borating without preliminary activation were established.

Features of the Structure Formation of Diffusion Boride Layers upon Preliminary Activation

2021 ◽  
Vol 903 ◽  
pp. 183-189
Author(s):  
Yulia Usherenko ◽  
Viktor Mironov ◽  
Vladimir Dashkevich
Keyword(s):  
Surface Treatment ◽  
Structure Formation ◽  
Diffusion Layer ◽  
Powder Composition ◽  
Diffusion Layers ◽  
Superdeep Penetration ◽  
High Boron ◽  
Preliminary Activation

The features of the structure formation of diffusion layers obtained by technology, including preliminary surface treatment of steel products made of U8 steel and subsequent boriding in powder media, have been investigated. The pretreatment consisted of dynamic alloying in the superdeep penetration (SDP) mode with a SiC-based powder composition. As a result, the thickness of the diffusion layer increases, its porosity decreases, and the proportion of the high-boron FeB phase in the layer increases.

NICROFER 5520 Co

Alloy Digest ◽  
1995 ◽  
Vol 44 (3) ◽  
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Temperatures ◽  
Heat Treating ◽  
High Temperature Corrosion ◽  
Creep Properties ◽  
Nickel Chromium ◽  
Temperature Performance

Abstract NICROFER 5520 Co is a nickel-chromium-cobalt-molybdenum alloy with excellent strength and creep properties up to high temperatures. Due to its balanced chemical composition the alloy shows outstanding resistance to high temperature corrosion in the form of oxidation and carburization. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-480. Producer or source: VDM Technologies Corporation.

Scaling Behavior of Superheater Tube Alloys in ASME High Temperature Steam Research Tests at 1100–1500 F

1962 ◽  
Vol 84 (3) ◽  
pp. 223-257 ◽  
Author(s):  
F. Eberle ◽  
C. H. Anderson
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Scaling Behavior ◽  
Effect Of Temperature ◽  
Relative Resistance ◽  
Superheater Tube ◽  
Shock Resistance ◽  
High Temperature Steam

The scales formed on seven ferritic and ten austenitic types of commercial tubing presently in use and of potential future use for superheater service were examined after 6, 12, and 18 months’ exposure to air and to flowing steam of 2000 psi at temperatures of 1100, 1200, 1350, and 1500 F. The effect of temperature and time of exposure on the adherence, thermal-shock resistance, thickness, structure, and chemical composition of the scales was investigated and the relative resistance to scaling of the various alloys evaluated.

scholarly journals Formation of Intermediate Phases and Supersaturated Solid Solution in Al-Cu System during Diffusion

2018 ◽  
Vol 383 ◽  
pp. 31-35 ◽  
Author(s):  
Alexey Rodin ◽  
Nataliya Goreslavets
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
High Temperature ◽  
Chemical Composition ◽  
Low Temperature ◽  
Supersaturated Solid Solution ◽  
Diffusion Processes ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Intermediate Phases

The study of diffusion processes in the aluminum - copper system was carried out at the temperature 350 and 520 °C. Special attention was paid on the chemical composition of the system near Al/Cu interface. It was determined that the intermediate phases in the system, corresponding to the equilibrium phase diagram, were not formed at low temperature. At high temperature the intermediate phases forms starting with Cu - rich phases. In both cases supersaturated solid solution of copper in aluminum could be observed near the interface.

scholarly journals Measurement of high-temperature strains in superalloy and carbon/carbon composites using chemical composition gratings

Strain ◽  
2016 ◽  
Vol 53 (1) ◽  
pp. e12218
Author(s):  
Weihua Xie ◽  
Songhe Meng ◽  
Hua Jin ◽  
Chong Du ◽  
Shiyu Huo ◽  
...  
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Carbon Composites

scholarly journals Effects of carbon content on high-temperature mechanical and thermal fatigue properties of high-boron austenitic steels

China Foundry ◽  
2016 ◽  
Vol 13 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Xiang Chen ◽  
Zhi-sheng Wang ◽  
Yan-xiang Li ◽  
Hua-wei Zhang ◽  
Yuan Liu
Keyword(s):  
High Temperature ◽  
Carbon Content ◽  
Thermal Fatigue ◽  
Austenitic Steels ◽  
Fatigue Properties ◽  
High Boron

scholarly journals Determination of Chromite Sands Suitability for Use in Moulding Sands

2017 ◽  
Vol 17 (2) ◽  
pp. 107-110
Author(s):  
K. Stec ◽  
J. Podwórny ◽  
B. Psiuk ◽  
Ł. Kozakiewicz
Keyword(s):  
Phase Composition ◽  
High Temperature ◽  
Chemical Composition ◽  
Chemical Properties ◽  
Grinding Process ◽  
X Ray Diffraction ◽  
Scanning Microscope ◽  
Spectroscopy Technique ◽  
X Ray

Abstract Using the available analytical methods, including the determination of chemical composition using wavelength-dispersive X-ray fluorescent spectroscopy technique and phase composition determined using X-ray diffraction, microstructural observations in a highresolution scanning microscope equipped with an X-ray microanalysis system as well as determination of characteristic softening and sintering temperatures using high-temperature microscope, the properties of particular chromite sands were defined. For the study has been typed reference sand with chemical properties, physical and thermal, treated as standard, and the sands of the regeneration process and the grinding process. Using these kinds of sand in foundries resulted in the occurrence of the phenomenon of the molding mass sintering. Impurities were identified and causes of sintering of a moulding sand based on chromite sand were characterized. Next, research methods enabling a quick evaluation of chromite sand suitability for use in the preparation of moulding sands were selected.

Trace elements in the system “soil-plants” and optimization of their use in agrocenoses of the Omsk Irtysh Land

2021 ◽  
pp. 42-61
Author(s):  
Yu. A. Azarenko
Keyword(s):  
Trace Elements ◽  
Crop Productivity ◽  
Climatic Conditions ◽  
Arable Soils ◽  
Factors Affecting ◽  
Geochemical Zoning ◽  
Effi Ciency ◽  
Quantitative Characteristics ◽  
High Boron ◽  
Zonal Soil

The data on the content and reserves of trace elements (Mn, Cu, Zn, Co, Mo, B) in soils, reveals patterns of their distribution and quantitative characteristics of relationships in the “soil-plants” system in agrocenoses of the Omsk Irtysh Land have been systematized in the article. The assessment of trace elements in soils and plants has been carried out from the ecological and agrochemical positions. The peculiarities of the intake and accumulation of trace elements in plants depending on zonal soil and climatic conditions have been revealed. Indicators for evaluating the potential of trace elements entering plants have been proposed, and its comparison for diff erent trace elements in the “soil-microfertilizerplant” system has been given. The use of this indicator in calculating and normalizing fertilizer doses and predicting the accumulation of trace elements in plants has been justified. The regularities of the distribution and shape of boron in diff erent types of soils of saline complexes have been studied. For the fi rst time a comprehensive assessment of the effect of high boron concentrations on crop productivity was carried out. A system of indicators for diagnosing the toxic eff ect of the element on plants and a scale of their borostability has been developed. The factors affecting the intake of boron in plants and their resistance to excess of the element have been revealed. Quantitative parameters of the eff ect of chemical reclamation on the boron content in the “soil-meliorant-plants” system have been obtained. The scheme of soil-geochemical zoning of the territory of the Omsk region reflecting the availability of trace elements in the soil has been developed. New data on the availability of trace elements in the main arable soils of the surveyed territory have been presented. The values of optimal levels of trace elements for agricultural crops were corrected. The economic and bioenergetic effi ciency of methods for optimizing plant nutrition with trace elements under the environments of agrocenoses of the Omsk Irtysh Land have been revealed.

A Study on Slag Composition inside Biomass Boiler System

2020 ◽  
Vol 901 ◽  
pp. 113-117
Author(s):  
Jirasak Tharajak ◽  
Noppakun Sanpo
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Slag Composition ◽  
Pulp And Paper ◽  
Critical Factors ◽  
Temperature Zone ◽  
Biomass Boiler ◽  
Factors Influencing ◽  
Steel Industries ◽  
Reliability And Availability

It was found that slagging in high temperature zone is one of the major problems in the refinery, petrochemical, pulp and paper, and steel industries; especially in biomass and coal pulverized power plant. Slagging conditions are critical factors influencing reliability and availability on a biomass utility boiler. In this study, several types of slagging were collected for chemical analysis. It was revealed that the chemical composition and other properties of received slagging showed unique results based on the type of feedstock fuel materials.

Active Chemistry Control for Coolant Helium Applying High-Temperature Gas-Cooled Reactors

2008 ◽  
Author(s):  
Nariaki Sakaba ◽  
Shimpei Hamamoto ◽  
Yoichi Takeda
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Exchanger ◽  
Chemical Composition ◽  
Structural Integrity ◽  
Carbon Deposition ◽  
Control Technology ◽  
Equilibrium Study ◽  
Intermediate Heat Exchanger ◽  
High Temperature Gas

Lifetime extension of high-temperature equipment such as the intermediate heat exchanger of high-temperature gas-cooled reactors (HTGRs) is important from the economical point of view. Since the replacing cost will cause the increasing of the running cost, it is important to reduce replacing times of the high-cost primary equipment during assumed reactor lifetime. In the past, helium chemistry has been controlled by the passive chemistry control technology in which chemical impurity in the coolant helium is removed as low concentration as possible, as does Japan’s HTTR. Although the lifetime of high-temperature equipment almost depends upon the chemistry conditions in the coolant helium, it is necessary to establish an active chemistry control technology to maintain adequate chemical conditions. In this study, carbon deposition which could occur at the surface of the heat transfer tubes of the intermediate heat exchanger and decarburization of the high-temperature material of Hastelloy XR used at the heat transfer tubes were evaluated by referring the actual chemistry data obtained by the HTTR. The chemical equilibrium study contributed to clarify the algorism of the chemistry behaviours to be controlled. The created algorism is planned to be added to the instrumentation system of the helium purification systems. In addition, the chemical composition to be maintained during the reactor operation was proposed by evaluating not only core graphite oxidation but also carbon deposition and decarburization. It was identified when the chemical composition could not keep adequately, injection of 10 ppm carbon monoxide could effectively control the chemical composition to the designated stable area where the high-temperature materials could keep their structural integrity beyond the assumed duration. The proposed active chemistry control technology is expected to contribute economically to the purification systems of the future very high-temperature reactors.

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