Corrosion product transformations in alkaline baths under pressure and high temperature: The sub-critical stabilisation of marine iron artefacts stored under atmospheric conditions

2015 ◽  
Vol 67 (2) ◽  
pp. 190-199 ◽  
Author(s):  
M. Bayle ◽  
P. de Viviés ◽  
J.-B. Memet ◽  
E. Foy ◽  
P. Dillmann ◽  
...  
CORROSION ◽  
10.5006/2802 ◽  
2018 ◽  
Vol 74 (9) ◽  
pp. 984-1000 ◽  
Author(s):  
Esmaeil Sadeghi ◽  
Nicolaie Markocsan ◽  
Tanvir Hussain ◽  
Matti Huhtakangas ◽  
Shrikant Joshi

NiCrMo coatings with and without dispersed SiO2 were deposited using high-velocity air-fuel technique. Thermogravimetric experiments were conducted in 5% O2 + 500 vppm HCl + N2 with and without a KCl deposit at 600°C for up to 168 h. The SiO2-containing coating showed lower weight change as a result of formation of a protective and adherent Cr-rich oxide scale. SiO2 decelerated short-circuit diffusion of Cr3+ through scale’s defects, e.g., vacancies, and promoted the selective oxidation of Cr to form the protective Cr-rich oxide scale. Furthermore, the presence of SiO2 led to less subsurface depletion of Cr in the coating, and accordingly less corrosion of the substrate. The formed corrosion product on the SiO2-free coating was highly porous, non-adherent, and thick.


2021 ◽  
Vol 2124 (1) ◽  
pp. 012013
Author(s):  
M N Roshchin

Abstract The results of high-temperature tribological tests of carbon-containing material in friction on heat-resistant stainless steel 40X13 in the temperature range from 20 to 700 °C under atmospheric conditions are presented. Friction surface modifiers “Argolon-2D” material improve antifriction properties and decrease friction coefficient value. Friction coefficient when using Ni-Se-PTFE modifier at load of 0.67 MPa and speed of 0.16 m/s is less by 5% than at speed of 0.05 m/s, and at speed of 0.25 m/s friction coefficient is less by 13% than at speed of 0.05 m/s. At 500 °C and a load of 0.67 MPa the friction coefficient when using Ni-Se-PTFE modifier is 30% higher than when using InSb-PTFE modifier, and the friction coefficient when using CuO-PTFE modifier is 1.2 times higher than when using InSb-PTFE modifier.


The effect of exercise on the human body has been made the subject of much study at different times. Researches have been carried out under atmospheric conditions such as prevail in different parts of Northern Europe, and they have been extended in a few instances to the effects of high temperature and humidity upon the human body. In the latter observations the conditions such as high temperature and varying humidity were produced by artificial means only, and general deductions as to the influence of an actual tropical climate upon the human organism cannot be safely drawn from them. In these experiments the subjects were living in a temperate climate, were exposed to heat and humidity for a short time only, and left the hot chamber at the end of the experiment for an atmosphere of coolness and comfort; in the tropics, on the other hand, the inhabitants are continuously exposed to heat and humidity without respite. Conclusions of real value can thus be drawn only from observations actually carried out in a hot climate, and systematic work in this direction is still lacking. Although observations have been made in the tropics on body temperature, blood pressure, pulse and respiration rate, and metabolism, yet their object has only been to obtain normal standards for the tropics for comparison with those of Europe.


CORROSION ◽  
1966 ◽  
Vol 22 (7) ◽  
pp. 191-193 ◽  
Author(s):  
CHARLES MILTON

Abstract “Kansite” is mackinawite, FeS. References to recent publications establishing this and correctly describing this important corrosion compound are given. Besides appearing as a corrosion product, it occurs naturally in tidal sediments, where hydrogen sulfide reacts with iron or iron compounds and in most high temperature copper and nickel ore deposits. It also has been synthesized in the laboratory. Mackinawite has been observed repeatedly for nearly a century, but until 1963 was generally confused with a similar-appearing but much rarer ore mineral, valleriite, CuFeS2, and was described under that name.


CORROSION ◽  
1998 ◽  
Vol 54 (6) ◽  
pp. 459-468 ◽  
Author(s):  
N. Arbeau ◽  
H. Allsop ◽  
R. H. Campbell ◽  
D. H. Lister

CORROSION ◽  
1961 ◽  
Vol 17 (4) ◽  
pp. 181t-184t ◽  
Author(s):  
D. F. MacLENNAN

Abstract A study was made of the behavior of aluminum alloys exposed to 300 G high purity water for short periods of time. The corrosion products formed were examined by means of optical and electron microscopy. Results show that corrosion resistance is associated with the distribution of second phase particles in the alloys. The alloy, which had the best corrosion resistance, contained the most uniform distribution of cathodic second phase particles; the corrosion product film of this alloy contained a corresponding distribution of irregularities. It is suggested that the second phase particles modify the film in such a way as to increase its protective qualities. 6.4.2, 4.6.5, 3.2.3


1983 ◽  
Vol 60 (3) ◽  
pp. 367-378 ◽  
Author(s):  
Hiromi Kanbe ◽  
Tadashi Inoue ◽  
Toshi Tomizawa ◽  
Hiroaki Kōyama ◽  
Hiroharu Itami

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1539
Author(s):  
Daquan Li ◽  
Qingjian Liu ◽  
Wenlong Wang ◽  
Lei Jin ◽  
Huaping Xiao

Seawater leakage commonly leads to corrosion in the inner lining of submarine bimetallic pipes, with significant financial implications for the offshore oil and gas production industry. This study aims to improve understanding of the performance of bimetallic pipes by investigating the corrosion behaviors of mechanically bonded 316L stainless steel. Immersion experiments were conducted in a seawater environment, under both atmospheric conditions and high temperature and high pressure conditions, and corroded surfaces were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to reveal micromorphology and elementary compositions. The results demonstrated that the corrosion rates of the bonded 316L specimen were between 5% and 20% higher than those of specimens without bonding under atmospheric conditions. This is attributed to the stress cracking that occurs during corrosion. Under high temperature and high pressure conditions, the corrosion rates were remarkably increased (91% to 135%) and the corrosion process took longer to reach equilibrium. This may be attributed, firstly, to the products becoming increasingly porous and weak, and also to the fluid stress caused by stirring in these experiments to simulate seawater movement.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5214
Author(s):  
Yihua Dou ◽  
Zhen Li ◽  
Jiarui Cheng ◽  
Yafei Zhang

The high pressure and high temperature (HPHT) flow solution containing various gases and Cl− ions is one of the corrosive environments in the use of oilfield tubing and casing. The changing external environment and complex reaction processes are the main factors restricting research into this type of corrosion. To study the corrosion mechanism in the coexistence of O2 and CO2 in a flowing medium, a HPHT flow experiment was used to simulate the corrosion process of N80 steel in a complex downhole environment. After the test, the material corrosion rate, surface morphology, micromorphology, and corrosion product composition were tested. Results showed that corrosion of tubing material in a coexisting environment was significantly affected by temperature and gas concentration. The addition of O2 changes the structure of the original CO2 corrosion product and the corrosion process, thereby affecting the corrosion law, especially at high temperatures. Meanwhile, the flowing boundary layer and temperature changed the gas concentration near the wall, which changed the corrosion priority and intermediate products on the metal surface. These high temperature corrosion conclusions can provide references for the anticorrosion construction work of downhole pipe strings.


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