The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
Rokuro Nishimura - One of the best experts on this subject based on the ideXlab platform.
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the stress corrosion cracking behavior of austenitic stainless steels in boiling magnesium chloride solutions
Corrosion Science, 2007Co-Authors: Osama M Alyousif, Rokuro NishimuraAbstract:Abstract The change in the mechanism of stress corrosion cracking with test temperature for Type 304, 310 and 316 austenitic stainless steels was investigated in boiling saturated magnesium chloride solutions using a constant load method. Three parameters (time to failure; t f , steady-state Elongation rate; l ss and transition time at which a linear increase in Elongation starts to deviate; t ss ) obtained from the corrosion Elongation Curve showed clearly three regions; stress-dominated, stress corrosion cracking-dominated and corrosion-dominated regions. In the stress corrosion cracking-dominated region the fracture mode of type 304 and 316 steels was transgranular at higher temperatures of 416 and 428 K, respectively, but was intergranular at a lower temperature of 408 K. Type 310 steel showed no intergranular fracture but only transgranular fracture. The relationship between log l ss and log t f for three steels became good straight lines irrespective of applied stress. The slope depended upon fracture mode; −2 for transgranular mode and −1 for intergranular mode. On the basis of the results obtained, it was estimated that intergranular cracking was resulted from hydrogen embrittlement due to strain-induced formation of martensite along the grain boundaries, while transgranular cracking took place by propagating cracks nucleated at slip steps by dissolution.
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the effect of test temperature on scc behavior of austenitic stainless steels in boiling saturated magnesium chloride solution
Corrosion Science, 2006Co-Authors: Osama M Alyousif, Rokuro NishimuraAbstract:Abstract The stress corrosion cracking (SCC) of the austenitic stainless steels of types 304, 310 and 316 was investigated as a function of test temperature in boiling saturated magnesium chloride solution (MgCl 2 ) using a constant load method. Both of types 304 and 316 exhibited similar corrosion Elongation Curves, while the corrosion Elongation Curve of type 310 was different from those of types 304 and 316, in terms of the three parameters such as time to failure ( t f ), steady-state Elongation rate ( l ss ) and transition time to time to failure ratio ( t ss / t f ) obtained from the corrosion Elongation Curves for these stainless steels. The relationship between the time to failure and a reciprocal of test temperature fell in two straight lines on a semi-logarithmic scale as well as the relationship between the steady-state Elongation rate and a reciprocal of test temperature. These regions were considered to correspond to a SCC-dominated region and a hydrogen embrittlement (HE)-dominated region from the value of ( t ss / t f ) and the fracture appearance. The relationship between the steady state Elongation rates versus time to failure on a logarithmic scale became a straight line, whereas the slopes of the line for the stainless steels were different with the different fracture mechanism such as SCC and HE. It was found that the linearity of the relationship can be used to predict the time to failure for the stainless steels in the corrosive environment. In addition, type 310 did not suffer from HE, which means that type 310 showed only SCC. This would be explained by whether or not a formation of α ′-martensite takes place.
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stress corrosion cracking of type 304 austenitic stainless steel in sulphuric acid solution including sodium chloride and chromate
Corrosion Science, 2004Co-Authors: Rokuro Nishimura, Yasuaki MaedaAbstract:Abstract The stress corrosion cracking (SCC) of a commercial austenitic stainless steel type 304 was investigated as functions of chloride concentration, chromate concentration and test temperature under a constant applied stress condition in 0.82 kmol/m3 sulphuric acid solution by using a constant load method. From the dependence of the three parameters ( l ss , steady state Elongation rate; tss, transition time; tf, time to failure) obtained from corrosion Elongation Curve on chloride/chromate concentrations and test temperature, a parameter for predicting time to failure and critical values of chromate concentration and test temperature, below which little SCC takes place, were estimated. In addition, a transgranular SCC mechanism was qualitatively inferred and then the effect of chromate and chloride on SCC behavior was discussed.
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stress corrosion cracking susceptibility of sensitized type 316 stainless steel in sulphuric acid solution
Corrosion Science, 2003Co-Authors: Rokuro Nishimura, Achmad Sulaiman, Yasuaki MaedaAbstract:Abstract The stress corrosion cracking (SCC) of a commercial austenitic stainless steel type 316 was investigated as a function of sensitizing temperature (800–1300 K) and test temperature (333–373 K) in 0.82 kmol/m 3 sulphuric acid solution by using a constant load method, to compare with that already obtained in 0.82 kmol/m 3 hydrochloric acid solution. The three parameters ( l ss , steady state Elongation rate, t ss , transition time, t f , time to failure) were obtained from corrosion Elongation Curve and were divided into three regions of applied stress, irrespective of sensitizing temperature, which are dominated by either stress, SCC or corrosion. In the SCC-dominated region, the logarithm of l ss was a linear function of the logarithm of t f regardless of applied stress and test temperature for each sensitized specimens, showing that l ss became a useful parameter for prediction of t f , although the slope depended upon sensitizing temperature. The maximum applied stress, the minimum applied stress and the value of t ss / t f in the SCC-dominated region depended upon sensitizing temperature. Specifically, at a sensitizing temperature of around 950 K the maximum applied stress was smaller at a test temperature of 353 K, but larger at a test temperature of 333 K than that of the solution annealed specimens. In addition, sulphate ions were found to become more aggressive than chloride ions for the SCC susceptibility of the specimens with the most severe sensitization. On the basis of the results obtained, the effect of sensitization on SCC, the role of sulphate ions and an intergranular mechanism were discussed in comparison to the results of the sensitized specimens obtained in 0.82 kmol/m 3 HCl solution.
P.-y.b. Jar - One of the best experts on this subject based on the ideXlab platform.
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determining stress strain relationship for necking in polymers based on macro deformation behavior
Finite Elements in Analysis and Design, 2013Co-Authors: S. Muhammad, P.-y.b. JarAbstract:Abstract An approach, based on mechanical testing and finite element modeling, is presented to establish the stress–strain relationship for polymers when necking evolves under tension. The paper gives details of criteria used for evaluating the stress–strain relationship during the necking process, and depicts how the total strain range is divided into several sections for the ease of the iterative calculation process. High-density polyethylene (HDPE) is used as a sample polymer to illustrate the approach. The results show that this approach can consider non-linear and creep deformation during the neck evolvement, and the stress–strain relationship established can be applied to a finite element model to regenerate force–Elongation Curve and cross-section reduction measured from the mechanical testing.
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Determining stress–strain relationship for necking in polymers based on macro deformation behavior
Finite Elements in Analysis and Design, 2013Co-Authors: S. Muhammad, P.-y.b. JarAbstract:Abstract An approach, based on mechanical testing and finite element modeling, is presented to establish the stress–strain relationship for polymers when necking evolves under tension. The paper gives details of criteria used for evaluating the stress–strain relationship during the necking process, and depicts how the total strain range is divided into several sections for the ease of the iterative calculation process. High-density polyethylene (HDPE) is used as a sample polymer to illustrate the approach. The results show that this approach can consider non-linear and creep deformation during the neck evolvement, and the stress–strain relationship established can be applied to a finite element model to regenerate force–Elongation Curve and cross-section reduction measured from the mechanical testing.
G. Vörös - One of the best experts on this subject based on the ideXlab platform.
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On the mathematical description of the tensile stress-strain Curves of polycrystalline face centered cubic metals
International Journal of Plasticity, 1996Co-Authors: István Kovács, G. VörösAbstract:The stress-strain Curves of polycrystalline face centered cubic metals (aluminium, copper, gold, silver and nickel) were measured by an Instron tensile test machine controlled by a computer registering 20 points per second along the load-Elongation Curve. The large number of measured points makes it possible to perform a detailed analysis of the mathematical structure of the stress-strain Curves. General conditions are introduced which must be fulfilled by the functions which approximately describe the whole stress-strain Curves. It is shown that the limiting value of a special set of suitable functions in practice describes the stress-strain Curves exactly.
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Tensile stress–strain Curves of polycrystalline silver
Physica Status Solidi (a), 1994Co-Authors: István Kovács, G. VörösAbstract:The stress–strain Curves of polycrystalline silver are measured by an Instron tensile test machine controlled by a computer registering 20 points per second of the load-Elongation Curve. The large number of the measured points makes it possible to perform a detailed analysis of the mathematical structure of the stress–strain Curves. An equation for the possible functions suitable to describe the Curves is established. It is shown that a limiting value of the functions satisfying this equation describes the stress–strain Curves practically exactly.
Yasuaki Maeda - One of the best experts on this subject based on the ideXlab platform.
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stress corrosion cracking of type 304 austenitic stainless steel in sulphuric acid solution including sodium chloride and chromate
Corrosion Science, 2004Co-Authors: Rokuro Nishimura, Yasuaki MaedaAbstract:Abstract The stress corrosion cracking (SCC) of a commercial austenitic stainless steel type 304 was investigated as functions of chloride concentration, chromate concentration and test temperature under a constant applied stress condition in 0.82 kmol/m3 sulphuric acid solution by using a constant load method. From the dependence of the three parameters ( l ss , steady state Elongation rate; tss, transition time; tf, time to failure) obtained from corrosion Elongation Curve on chloride/chromate concentrations and test temperature, a parameter for predicting time to failure and critical values of chromate concentration and test temperature, below which little SCC takes place, were estimated. In addition, a transgranular SCC mechanism was qualitatively inferred and then the effect of chromate and chloride on SCC behavior was discussed.
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stress corrosion cracking susceptibility of sensitized type 316 stainless steel in sulphuric acid solution
Corrosion Science, 2003Co-Authors: Rokuro Nishimura, Achmad Sulaiman, Yasuaki MaedaAbstract:Abstract The stress corrosion cracking (SCC) of a commercial austenitic stainless steel type 316 was investigated as a function of sensitizing temperature (800–1300 K) and test temperature (333–373 K) in 0.82 kmol/m 3 sulphuric acid solution by using a constant load method, to compare with that already obtained in 0.82 kmol/m 3 hydrochloric acid solution. The three parameters ( l ss , steady state Elongation rate, t ss , transition time, t f , time to failure) were obtained from corrosion Elongation Curve and were divided into three regions of applied stress, irrespective of sensitizing temperature, which are dominated by either stress, SCC or corrosion. In the SCC-dominated region, the logarithm of l ss was a linear function of the logarithm of t f regardless of applied stress and test temperature for each sensitized specimens, showing that l ss became a useful parameter for prediction of t f , although the slope depended upon sensitizing temperature. The maximum applied stress, the minimum applied stress and the value of t ss / t f in the SCC-dominated region depended upon sensitizing temperature. Specifically, at a sensitizing temperature of around 950 K the maximum applied stress was smaller at a test temperature of 353 K, but larger at a test temperature of 333 K than that of the solution annealed specimens. In addition, sulphate ions were found to become more aggressive than chloride ions for the SCC susceptibility of the specimens with the most severe sensitization. On the basis of the results obtained, the effect of sensitization on SCC, the role of sulphate ions and an intergranular mechanism were discussed in comparison to the results of the sensitized specimens obtained in 0.82 kmol/m 3 HCl solution.
S. Muhammad - One of the best experts on this subject based on the ideXlab platform.
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determining stress strain relationship for necking in polymers based on macro deformation behavior
Finite Elements in Analysis and Design, 2013Co-Authors: S. Muhammad, P.-y.b. JarAbstract:Abstract An approach, based on mechanical testing and finite element modeling, is presented to establish the stress–strain relationship for polymers when necking evolves under tension. The paper gives details of criteria used for evaluating the stress–strain relationship during the necking process, and depicts how the total strain range is divided into several sections for the ease of the iterative calculation process. High-density polyethylene (HDPE) is used as a sample polymer to illustrate the approach. The results show that this approach can consider non-linear and creep deformation during the neck evolvement, and the stress–strain relationship established can be applied to a finite element model to regenerate force–Elongation Curve and cross-section reduction measured from the mechanical testing.
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Determining stress–strain relationship for necking in polymers based on macro deformation behavior
Finite Elements in Analysis and Design, 2013Co-Authors: S. Muhammad, P.-y.b. JarAbstract:Abstract An approach, based on mechanical testing and finite element modeling, is presented to establish the stress–strain relationship for polymers when necking evolves under tension. The paper gives details of criteria used for evaluating the stress–strain relationship during the necking process, and depicts how the total strain range is divided into several sections for the ease of the iterative calculation process. High-density polyethylene (HDPE) is used as a sample polymer to illustrate the approach. The results show that this approach can consider non-linear and creep deformation during the neck evolvement, and the stress–strain relationship established can be applied to a finite element model to regenerate force–Elongation Curve and cross-section reduction measured from the mechanical testing.