The effect of furnace tube material on the oxidation of an Fe10%Cr alloy at 600°C

1980 ◽  
Vol 20 (3) ◽  
pp. 457-460 ◽  
Author(s):  
J.E. Rhoades-Brown ◽  
S.R.J. Saunders
Keyword(s):  
Tube Material ◽  
Furnace Tube

scholarly journals Effect of Total Pressure and Furnace Tube Material on the Oxidation of T22 in Humidified Air

2021 ◽  
Author(s):  
Clara Schlereth ◽  
Mathias C. Galetz
Keyword(s):  
Cross Sections ◽  
Base Alloy ◽  
Gas Composition ◽  
Oxide Scales ◽  
Tube Material ◽  
System Pressure ◽  
Furnace Tube ◽  
Adsorption Rates ◽  
Humidified Air ◽  
Micro Analysis

AbstractOxidation of the Fe-base alloy T22 in humid air at 500 °C was investigated. The samples were exposed for up to 1000 h at 1 bar and 20 bar. The influence of three furnace tube materials, alumina, ET45 and quartz glass, on the oxide scale morphology was investigated. Samples and their cross sections were examined using optical microscopy, scanning electron microscopy, electron probe micro analysis and Raman spectroscopy. Multilayered oxide scales consisting of hematite, magnetite and Fe–Cr spinel were found on all samples. However, the composition and morphology of the oxide scales depend on the furnace tube material and on the system pressure. The system pressure is assumed to change the reaction equilibria and adsorption rates. The tube material changed the initial gas composition by formation of volatile Cr species. This volatilization rate increased at higher system pressures.

Microanalytical Identification of a New Zr-Nb-Fe Phase

1990 ◽  
Vol 48 (2) ◽  
pp. 132-133
Author(s):  
O.T. Woo ◽  
G.J.C. Carpenter
Keyword(s):  
Trace Elements ◽  
Cold Rolling ◽  
Proportionality Factor ◽  
Tube Material ◽  
X Ray ◽  
Metal Foils ◽  
Arc Melting ◽  
Intermetallic Particles ◽  
Intermetallic Precipitates ◽  
Cold Worked

To study the influence of trace elements on the corrosion and hydrogen ingress in Zr-2.5 Nb pressure tube material, buttons of this alloy containing up to 0.83 at% Fe were made by arc-melting. The buttons were then annealed at 973 K for three days, furnace cooled, followed by ≈80% cold-rolling. The microstructure of cold-worked Zr-2.5 at% Nb-0.83 at% Fe (Fig. 1) contained both β-Zr and intermetallic precipitates in the α-Zr grains. The particles were 0.1 to 0.7 μm in size, with shapes ranging from spherical to ellipsoidal and often contained faults. β-Zr appeared either roughly spherical or as irregular elongated patches, often extending to several micrometres.The composition of the intermetallic particles seen in Fig. 1 was determined using Van Cappellen’s extrapolation technique for energy dispersive X-ray analysis of thin metal foils. The method was employed to avoid corrections for absorption and fluorescence via the Cliff-Lorimer equation: CA/CB = kAB · IA/IB, where CA and CB are the concentrations by weight of the elements A and B, and IA and IB are the X-ray intensities; kAB is a proportionality factor.

Effects of Forging Reduction on 120-mm M256 Tube Material

1991 ◽  
Author(s):  
Charles Calderone ◽  
John Senick
Keyword(s):  
Tube Material

Variations in nanomechanical properties of back-end Zr–2.5Nb pressure tube material

2013 ◽  
Vol 442 (1-3) ◽  
pp. 116-123 ◽  
Author(s):  
Matthew Gallaugher ◽  
Daniel Peykov ◽  
Nicolas Brodusch ◽  
Richard R. Chromik ◽  
Lisa Rodrigue ◽  
...  
Keyword(s):  
Pressure Tube ◽  
Tube Material ◽  
Nanomechanical Properties

Interfacial dynamics of stationary gas bubbles in flows in inclined tubes

1999 ◽  
Vol 398 ◽  
pp. 225-244 ◽  
Author(s):  
DANIEL P. CAVANAGH ◽  
DAVID M. ECKMANN
Keyword(s):  
Pressure Gradient ◽  
Bubble Size ◽  
Contact Angle Hysteresis ◽  
Gas Bubbles ◽  
Solid Material ◽  
Contact Forces ◽  
Tube Material ◽  
Experimental Conditions ◽  
Axial Pressure Gradient ◽  
Inclination Angles

We have experimentally examined the effects of bubble size (0.4 [les ] λ [les ] 2.0), inclination angle (0° [les ] α [les ] 90°), and tube material on suspended gas bubbles in flows in tubes for a range of Weber (0 [les ] We [les ] 3.6), Reynolds (0 [les ] Re [les ] 1200), and Froude (0 [les ] Frα [les ] 1) numbers. Flow rates and associated pressure differences which allow the suspension of bubbles in glass and acrylic tubes are measured. Due to contact angle hysteresis, bubbles which dry the tube wall (i.e. form a gas–solid interface) may remain suspended over a range of flows while non-drying bubbles remain stationary for a single flow rate depending on experimental conditions. Stationary bubbles increase the axial pressure gradient with larger bubbles and steeper inclination angles leading to the greatest increase in the pressure gradient. Both the suspension flow range and pressure difference modifications are strongly dependent upon gas/liquid/solid material interactions. Stronger contact forces, i.e. smaller spreading coefficients, cause dried bubbles in acrylic tubes to remain stationary over a wider range of suspension flows than bubbles in glass tubes. Bubble deformation is governed by the interaction of interfacial, contact, and flow-derived forces. This investigation reveals the importance of bubble size, tube inclination, and tube material on gas bubble suspension.

Engineering Relation for Dependence of Threshold Stress Intensity Factor for Delayed Hydride Cracking on Crack Orientation

2008 ◽  
Author(s):  
Douglas A. Scarth ◽  
Gordon K. Shek ◽  
Steven X. Xu
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Threshold Stress ◽  
Pressure Tube ◽  
Threshold Stress Intensity ◽  
Tube Material ◽  
Fuel Bundle ◽  
Threshold Stress Intensity Factor ◽  
Cold Worked

Delayed Hydride Cracking (DHC) in cold-worked Zr-2.5 Nb pressure tubes is of interest to the CANDU industry in the context of the potential to initiate DHC at an in-service flaw. Examples of in-service flaws are fuel bundle scratches, crevice corrosion marks, fuel bundle bearing pad fretting flaws and debris fretting flaws. To date, experience with fretting flaws has been favourable, and crack growth from an in-service fretting flaw has not been detected. However, postulated DHC growth from these flaws can result in severe restrictions on the allowable number of reactor Heatup/Cooldown cycles prior to re-inspection of the flaw, and it is important to reduce any unnecessary conservatism in the evaluation of DHC from the flaw. One method to reduce conservatism is to take credit for the increase in the isothermal threshold stress intensity factor for DHC initiation at a crack, KIH, as the flaw orientation changes from an axial flaw to a circumferential flaw in the pressure tube. This increase in KIH is due to the texture of the pressure tube material. An engineering relation that provides the value of KIH as a function of the orientation of the flaw relative to the axial direction in the pressure tube has been developed as described in this paper. The engineering relation for KIH has been validated against results from DHC initiation experiments on unirradiated cold-worked Zr-2.5 Nb pressure tube material.

scholarly journals Solar Thermal Power: Appraisal of Solar Power Towers

2018 ◽  
Vol 225 ◽  
pp. 04003
Author(s):  
Hashem Shatnawi ◽  
Chin Wai Lim ◽  
Firas Basim Ismail
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Solar Power ◽  
Thermal Power ◽  
Tube Material ◽  
Power Cycles ◽  
Solar Thermal Power ◽  
Central Receiver ◽  
Receiver System ◽  
Solar Power Tower

This study delves into several engineering procedures related to solar power tower plants. These installations come with central receiver system technologies and high-temperature power cycles. Besides a summary emphasizing on the fundamental components of a solar power tower, this paper also forwards a description of three receiver designs. Namely, these are the tubular receiver, the volumetric receiver and the direct absorber receiver. A variety of heat transfer mediums were assessed, while a comprehensive explanation was provided on the elements of external solar cylindrical receivers. This explanation covers tube material, molten salt, tube diameter and heat flux.

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