Strain Enhanced Corrosion in the Iron-Caustic System

CORROSION ◽  
1976 ◽  
Vol 32 (9) ◽  
pp. 353-357 ◽  
Author(s):  
RONALD B. DIEGLE ◽  
DAVID A. VERMILYEA
Keyword(s):  
Steady State ◽  
Corrosion Rate ◽  
Strain Rate ◽  
Electrolyte Concentration ◽  
Applied Strain ◽  
Crack Advance ◽  
Film Rupture ◽  
Applied Strain Rate ◽  
Corrosion Of Iron ◽  
Kinetics Of

Abstract Straining electrode experiments were performed to investigate the nature of strain enhanced corrosion of iron in caustic electrolyte. The strain enhanced corrosion rate was generally linearly dependent on applied strain rate, and its potential dependence paralleled that of steady-state polarization behavior on non-straining electrodes. Data was presented as ratios, in which is the corrosion rate in cm/s and is the corresponding strain rate. This ratio, which was shown in a previously published theory to be numerically equal to the crack advance per film rupture event during film rupture SCC, depended on electrochemical variables such as electrolyte concentration and temperature in a manner similar to the kinetics of caustic cracking. Conditions which are known to be marginal in producing caustic cracking resulted in values for of about 10−7 cm, in excellent agreement with a previously developed theory. It was concluded that strain enhanced corrosion in this system results from repetitive film rupture and repair during straining.

Influence of Silicon and Manganese on Corrosion Behavior of Austenitic Stainless Steels

CORROSION ◽  
1968 ◽  
Vol 24 (12) ◽  
pp. 393-402 ◽  
Author(s):  
B. E. WILDE ◽  
J. S. ARMIJO
Keyword(s):  
Steady State ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Stainless Steels ◽  
High Purity ◽  
Composition Range ◽  
Austenitic Stainless Steels ◽  
Dissolution Kinetics ◽  
Kinetics Of ◽  
Partial Process

Abstract The influence of silicon and manganese on the electrochemical and corrosion behavior of a high purity austenitic 14Cr/14Ni-balance Fe alloy has been studied. Over the composition range 50–41, 500 ppm Si, no effect was observed on the kinetics of the anodic or cathodic partial processes. Addition of manganese over the range 5–26,300 ppm accelerates the anodic dissolution kinetics in the active range of potentials and also the steady-state corrosion rate in 1N̄ H2SO4 due to its influence on the kinetics of the cathodic partial process. The nature of this effect is analyzed according to electrode kinetic concepts from which it is shown that manganese changes the value of the electrode process transmission coefficient. Alloys containing manganese and silicon over large concentration ranges are extremely resistant to stress corrosion cracking in boiling 42 w/o MgCl2.

Investigating the effect of applied strain rate in a single breakage event

2017 ◽  
Vol 100 ◽  
pp. 211-222 ◽  
Author(s):  
Fatemeh Saeidi ◽  
Mohsen Yahyaei ◽  
Malcolm Powell ◽  
Luís Marcelo Tavares
Keyword(s):  
Strain Rate ◽  
Applied Strain ◽  
Applied Strain Rate

scholarly journals Dynamic Mechanical and Microstructural Properties of Outburst-Prone Coal Based on Compressive SHPB Tests

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4236 ◽  
Author(s):  
Yang ◽  
Fan ◽  
Lan ◽  
Li ◽  
Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Strain Rate ◽  
Impact Loading ◽  
Applied Strain ◽  
Sudden Increase ◽  
Microstructural Properties ◽  
Stress Strain ◽  
Dynamic Mechanical ◽  
Applied Strain Rate

Understanding the dynamic mechanical behaviors and microstructural properties of outburst-prone coal is significant for preventing coal and gas outbursts during underground mining. In this paper, the split Hopkinson pressure bar (SHPB) tests were completed to study the strength and micro-structures of outburst-prone coal subjected to compressive impact loading. Two suites of coals—outburst-prone and outburst-resistant—were selected as the experimental specimens. The characteristics of dynamic strength, failure processes, fragment distribution, and microstructure evolution were analyzed based on the obtained stress-strain curves, failed fragments, and scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) images. Results showed that the dynamic compressive strength inclined linearly with the applied strain rate approximately. The obtained dynamic stress-strain responses could be represented by a typical curve with stages of compression, linear elasticity, microcrack evolution, unstable crack propagation, and rapid rapture. When the loading rate was relatively low, fragments fell in tension. With an increase in loading rates, the fragments fell predominantly in shear. The equivalent particle size of coal fragments decreased with the applied strain rate. The Uniaxial compressive strength (UCS) of outburst-prone coal was smaller than that of resistant coal, resulting in its smaller equivalent particle size of coal fragments. Moreover, the impact loading accelerated the propagation of fractures within the specimen, which enhanced the connectivity within the porous coal. The outburst-prone coal with behaviors of low strength and sudden increase of permeability could easily initiate gas outbursts.

Kinetic analysis of mechanism of intestinal Na+-dependent sugar transport

1985 ◽  
Vol 248 (5) ◽  
pp. C498-C509 ◽  
Author(s):  
D. Restrepo ◽  
G. A. Kimmich
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Sugar Transport ◽  
Enzyme Kinetic ◽  
Steady State Distribution ◽  
State Distribution ◽  
Least Squares Fit ◽  
Coupling Stoichiometry ◽  
Rate Limiting ◽  
Kinetics Of

Zero-trans kinetics of Na+-sugar cotransport were investigated. Sugar influx was measured at various sodium and sugar concentrations in K+-loaded cells treated with rotenone and valinomycin. Sugar influx follows Michaelis-Menten kinetics as a function of sugar concentration but not as a function of Na+ concentration. Nine models with 1:1 or 2:1 sodium:sugar stoichiometry were considered. The flux equations for these models were solved assuming steady-state distribution of carrier forms and that translocation across the membrane is rate limiting. Classical enzyme kinetic methods and a least-squares fit of flux equations to the experimental data were used to assess the fit of the different models. Four models can be discarded on this basis. Of the remaining models, we discard two on the basis of the trans sodium dependence and the coupling stoichiometry [G. A. Kimmich and J. Randles, Am. J. Physiol. 247 (Cell Physiol. 16): C74-C82, 1984]. The remaining models are terter ordered mechanisms with sodium debinding first at the trans side. If transfer across the membrane is rate limiting, the binding order can be determined to be sodium:sugar:sodium.

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