scholarly journals Effect of Rolling Deformation on Creep Properties of FeCrAl Alloys

2021 ◽  
Vol 9 ◽  
Author(s):  
Huan Sheng Lai ◽  
Jingyu Guo ◽  
Shanglin Zhang ◽  
Xiaobin Yu ◽  
Fanqiang Meng ◽  
...  
Keyword(s):  
Creep Test ◽  
Hot Rolling ◽  
Process Condition ◽  
Thickness Reduction ◽  
Indentation Creep ◽  
Process Conditions ◽  
Creep Properties ◽  
Nano Indentation ◽  
Fecral Alloy ◽  
The Impact

FeCrAl alloy is one of the most promising nuclear fuel claddings among many accident tolerant fuel (ATF) materials due to its excellent oxidation resistance and good mechanical properties. However, the effect of process conditions on the creep properties of the FeCrAl alloy is not clear till now. In this study, the impact of a process condition of hot-rolling on the creep properties of FeCrAl alloy was investigated using a nano-indentation creep test under a temperature of 350°C. The microanalysis results indicated that the grain size became smaller with the increase of the hot-rolling thickness reduction. The nano-indentation creep test results showed that the creep power-law stress exponent was about four, and the creep resistance increased when the hot-rolling thickness reduction increased.

Effect of Surface Roughness on Determination of Creep Parameter using Impression Creep Technique

2009 ◽  
Vol 1224 ◽  
Author(s):  
Wuzhu Yan ◽  
Bin Zhao ◽  
Zhufeng Yue
Keyword(s):  
Surface Roughness ◽  
Creep Test ◽  
Crucial Role ◽  
Indentation Creep ◽  
Impression Creep ◽  
Creep Parameter ◽  
Creep Properties ◽  
Properties Of Materials ◽  
Effect Of Surface

AbstractThe indentation creep test, especially the impression creep, exhibits a magic appealing in the determination of creep properties of small structures in industry for its simplicity, efficiency and non-destruction merits. Most of previous researches of indentation or impression creep neglect the effect of surface roughness of materials, which plays a crucial role in extracting creep properties of materials. The FE results showed that the surface roughness has no effect on the determination of creep exponent when the punching stress is larger than 150MPa. However, under a smaller punching stress the stress exponent is decreased due to the “Tuner” effect of asperities. The conclusions drawn in the present study provide an important guidance on experiment results amendment for impression creep technique.

scholarly journals Indicative Marker Microbiome Structures Deduced from the Taxonomic Inventory of 67 Full-Scale Anaerobic Digesters of 49 Agricultural Biogas Plants

2021 ◽  
Vol 9 (7) ◽  
pp. 1457
Author(s):  
Julia Hassa ◽  
Johanna Klang ◽  
Dirk Benndorf ◽  
Marcel Pohl ◽  
Benedikt Hülsemann ◽  
...  
Keyword(s):  
Stable Process ◽  
Process Condition ◽  
Full Scale ◽  
Process Models ◽  
Process Efficiency ◽  
Process Conditions ◽  
Rrna Gene ◽  
General Process ◽  
Specific Distribution ◽  
Biogas Plants

There are almost 9500 biogas plants in Germany, which are predominantly operated with energy crops and residues from livestock husbandry over the last two decades. In the future, biogas plants must be enabled to use a much broader range of input materials in a flexible and demand-oriented manner. Hence, the microbial communities will be exposed to frequently varying process conditions, while an overall stable process must be ensured. To accompany this transition, there is the need to better understand how biogas microbiomes respond to management measures and how these responses affect the process efficiency. Therefore, 67 microbiomes originating from 49 agricultural, full-scale biogas plants were taxonomically investigated by 16S rRNA gene amplicon sequencing. These microbiomes were separated into three distinct clusters and one group of outliers, which are characterized by a specific distribution of 253 indicative taxa and their relative abundances. These indicative taxa seem to be adapted to specific process conditions which result from a different biogas plant operation. Based on these results, it seems to be possible to deduce/assess the general process condition of a biogas digester based solely on the microbiome structure, in particular on the distribution of specific indicative taxa, and without knowing the corresponding operational and chemical process parameters. Perspectively, this could allow the development of detection systems and advanced process models considering the microbial diversity.

Indenter misalignment in impression creep test: Uncertainty, correction and recommendation

2021 ◽  
pp. 030932472199765
Author(s):  
Suo Li ◽  
Dean Deng ◽  
Wei Sun
Keyword(s):  
Creep Test ◽  
Vertical Direction ◽  
Steady State Creep ◽  
Impression Creep ◽  
Finite Element Analyses ◽  
Empirical Formulas ◽  
Test Technique ◽  
Creep Properties ◽  
Miniature Specimen ◽  
Specimen Test

The impression creep test (ICT) method, as a miniature specimen test technique, has been used extensively to determine the in-service creep properties of power plant components. However, the experiment results of the ICT can be affected by some uncertainties associated with the inaccuracies of measurement, which have not been studied before. This paper presents some results of finite element analyses, to evaluate the effect of indenter misalignment on the results of the ICT, such as the steady-state creep deformation rate and the conversion parameters. The results obtained have shown that the angular misalignments of the indenter around horizontal directions have a relatively significant influence on the conversion parameters, and the misalignment around vertical direction has a much less significant effect. Empirical formulas were developed for the possible correction of the conversion factors. Finally, some recommendations on the control of the indenter and specimen alignment were given.

A Method for Evaluating Intensity of Water Cavitation Peening Processing

2011 ◽  
Vol 675-677 ◽  
pp. 747-750
Author(s):  
B. Han ◽  
Dong Ying Ju ◽  
Xiao Guang Yu
Keyword(s):  
Residual Stress ◽  
Process Capability ◽  
Diffraction Method ◽  
Spring Steel ◽  
Bubble Collapse ◽  
Plastic Layer ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
Near Surface ◽  
The Impact

Water cavitation peening (WCP) with aeration, namely, a new ventilation nozzle with aeration is adopted to improve the process capability of WCP by increasing the impact pressure induced by the bubble collapse on the surface of components. In this study, in order to investigate the process capability of the WCP with aeration a standard N-type almen strips of spring steel SAE 1070 was treated byWCP with various process conditions, and the arc height value and the residual stress in the superficial layers were measured by means of the Almen-scale and X-ray diffraction method, respectively. The optimal fluxes of aeration and the optimal standoff distances were achieved. The maximum of arc height value reach around 150μm. The depth of plastic layer observed from the results of residual stresses is up to 150μm. The results verify the existence of macro-plastic strain in WCP processing. The distributions of residual stress in near-surface under different peening intensity can provide a reference for engineers to decide the optimal process conditions of WCP processing.

Structuring of Silicon Wafer Surfaces on the Sub-100 nm Scale by Hydrogen Plasma Treatments

2003 ◽  
Vol 788 ◽  
Author(s):  
R. Job ◽  
Y. Ma ◽  
A. G. Ulyashin
Keyword(s):  
Hydrogen Plasma ◽  
Structural Defects ◽  
Process Conditions ◽  
Force Microscopy ◽  
Czochralski Silicon ◽  
Atomic Force ◽  
Nano Structures ◽  
Plasma Treatments ◽  
The Impact ◽  
Wafer Surfaces

ABSTRACTHydrogen plasma treatments applied on standard Czochralski silicon (Cz Si) wafers cause a structuring of the surface regions on the sub-100 nm scale, i.e. a thin ‘nano-structured’ Si layer is created up to a depth of ∼ 150 nm. The formation of the ‘nano-structures’ and their evolution in dependence on the process conditions was studied. The impact of post-hydrogenation annealing on the morphology of the structural defects was studied up to 1200 °C. The H-plasma treated and annealed samples were analyzed at surface and sub-surface regions by scanning electron microscopy (SEM), atomic force microscopy (AFM), and μ-Raman spectroscopy.

Impact of high pressure processing on microbiological, nutritional and sensory properties of food: a review

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ajith Amsasekar ◽  
Rahul S. Mor ◽  
Anand Kishore ◽  
Anupama Singh ◽  
Saurabh Sid
Keyword(s):  
High Pressure ◽  
Food Quality ◽  
High Pressure Processing ◽  
Microbial Inactivation ◽  
Sensory Properties ◽  
Process Conditions ◽  
Processed Food ◽  
Content Type ◽  
Food Properties ◽  
The Impact

Purpose The increased demand for high-quality, nutritionally rich processed food has led to non-thermal food processing technologies like high pressure processing (HPP), a novel process for microbial inactivation with minimal loss of nutritional and sensory properties. The purpose of this paper is to highlight the impact of HPP on the microbiological, nutritional and sensory properties of food. Design/methodology/approach Recent research on the role of HPP in maintaining food quality and safety and the impact of process conditions with respect to various food properties have been explored in this paper. Also, the hurdle approach and the effectiveness of HPP on food quality have been documented. Findings HPP has been verified for industrial application, fulfilling the consumer demand for processed food with minimum nutrition loss at low temperatures. The positive impact of HPP with other treatments is known as the hurdle approach that enhances its impact against microorganism activity and minimizes the effects on nutrition and sensory attributes. Originality/value This paper highlights the impact of HPP on various food properties and a good alternative as non-thermal technology for maintaining shelf life, sensory properties and retention of nutrients.

Indentation Creep of Molybdenum: Comparison Between Thin Film and Bulk Material

1994 ◽  
Vol 356 ◽  
Author(s):  
K. B. Yoder ◽  
D. S. Stone ◽  
J. C. Lin ◽  
R. A. Hoffmann
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Room Temperature ◽  
Bulk Material ◽  
High Hardness ◽  
Rate Sensitivity ◽  
Indentation Creep ◽  
Creep Properties ◽  
Measurement Path ◽  
Arc Evaporation

AbstractIndentation creep, load relaxation, and rate-change experiments probe room temperature and 80°C creep properties of a 1.3 μm-thick molybdenum film on silicon. The film, with 0.51 GPa compressive stress, 8 GPa hardness and estimated 40 nm grain size, was deposited using steered-arc evaporation at -17V bias. Despite its small grain size and high hardness, the thin film behaves like bulk molybdenum does: the rate sensitivity of the hardness is only weakly-dependent on measurement path (as with bulk material), and activation volumes calculated based on strain rate sensitivity are consistent with those of bulk molybdenum We suspect deformation mechanisms are similar to those in bulk molybdenum under similar conditions.

scholarly journals Generalization of research results on the dynamics of continuous wide-strip hot-rolling mills

2018 ◽  
pp. 275-289
Author(s):  
V.V. Verenev
Keyword(s):  
Mathematical Model ◽  
Hot Rolling ◽  
Large Data ◽  
Dynamic Processes ◽  
Technological Parameters ◽  
Rolling Moment ◽  
Rolling Mills ◽  
Wide Strip ◽  
The Impact ◽  
First Time

The aim of the work is to summarize the results of experimental-industrial and theoretical studies of dynamic processes in wide-strip hot rolling mills 1680, 1700, 2000 and 2500. We describe the methods of collecting, storing, identifying, visualizing and mathematical processing of large data arrays, which made it possible to establish new laws and correlations of technological parameters. New results related to the peculiarities of transient processes, their patterns and the use of the latter for the purpose of diagnosing technology and equipment condition are presented. Vibrodynamic processes are described when the strip is captured by the rollers. For the first time, a correlation between the maximum peak moment when the strip is captured and the static rolling moment on the 1680 mill is obtained and substantiated by measuring and statistical modeling. A new mathematical model of the roll line is developed, incorporating the equations of dynamic processes in gears and axles of the gearbox. For the first time, the dynamics of the formation of intercellular tensions in the process of sequential filling and release with a 6-cell band is shown. A complete mathematical model and a computer program for the dynamic interaction of six-group stands of a rolling strip have been developed. A new line of research has been proposed, which includes the search, substantiation and testing of new methods and methods for diagnosing the technical condition of rolling mills based on the use of transients and their parameters in various modes of equipment operation. Proposed and tested in industrial conditions at the mills 1680 and 1700-M are effective ways to reduce the impact loads during the period of the strip capture by the rollers.

Experimental Investigation on Intensity and Residual Stress in Superficial Layers Induced by Water Cavitation Peening with Aeration

2008 ◽  
Vol 373-374 ◽  
pp. 754-757 ◽  
Author(s):  
Dong Ying Ju ◽  
B. Han
Keyword(s):  
Residual Stress ◽  
Process Capability ◽  
Diffraction Method ◽  
Spring Steel ◽  
Bubble Collapse ◽  
Process Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Enhancement Method ◽  
The Impact

Water cavitation peening (WCP) with aeration is a novel surface enhancement method. A new ventilation nozzle with aeration is adopted to improve the process capability of WCP by increasing the impact pressure induced by the bubble collapse on the surface of components. In this study, in order to investigate the process capability of the WCP with aeration, a standard N-type almen strips of spring steel SAE 1070 was treated by WCP with various process conditions, and the arc height value and the residual stress in the superficial layers were measured by X-ray diffraction method. The optimal fluxes of aeration and the optimal standoff distances were achieved.

Effect of carburizing and annealing processes in improving the Ni/WC–Co adhesion strength

2017 ◽  
Vol 232 (3) ◽  
pp. 338-348 ◽  
Author(s):  
AW Hassan ◽  
MY Noordin ◽  
S Izman ◽  
K Denni
Keyword(s):  
Heat Treatment ◽  
Adhesion Strength ◽  
Positive Impact ◽  
Process Condition ◽  
Scratch Test ◽  
Process Conditions ◽  
X Ray ◽  
Treatment Processes ◽  
Before And After ◽  
Field Emission Electron Microscopy

Heat treatment processes have a positive impact in improving the adhesion strength of different interlayer/substrate materials. However, information regarding the effect of these processes in enhancing the adhesion strength of an electroplated nickel interlayer on tungsten carbide substrate for diamond deposition is lacking. In this study, the effect of carburizing and annealing process conditions in enhancing the adhesion strength of the electroplated nickel interlayer was investigated. The heat treatment processes were designed and modeled by the design of experiments technique. The heat-treated specimens were characterized by the field-emission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction techniques. The adhesion of the interlayer before and after the heat treatment was assessed by the scratch test. The results show that the adhesion of the electroplated nickel interlayer was remarkably improved by both processes. The mathematical models for predicting the adhesion strength of the carburized and annealed nickel interlayer within the specified ranges were developed. The maximum adhesion strength of 30 N was obtained from the nickel interlayer annealed at the highest process condition of temperature and time.

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