Corrosion of metals and alloys. Accelerated cyclic test with exposure to acidified salt spray, dry and wet conditions

2018 ◽  
Keyword(s):  
Salt Spray ◽  
Metals And Alloys ◽  
Cyclic Test ◽  
Spray Dry ◽  
Dry And Wet Conditions

Atmospheric Corrosion Behavior Assessment of Carbon Steel Pipes Using Cyclic Salt Spray Test

2015 ◽  
Vol 658 ◽  
pp. 42-52
Author(s):  
Polporn Chatisathien ◽  
Nuttapon Suttitam
Keyword(s):  
Carbon Steel ◽  
Corrosion Behavior ◽  
Atmospheric Corrosion ◽  
Salt Spray ◽  
Metals And Alloys ◽  
Salt Spray Test ◽  
Cover Plate ◽  
Steel Pipes ◽  
Inner Surface ◽  
Welded Pipe

Accelerated atmospheric corrosion behavior of carbon steel pipes subjected to cyclic salt spray test was performed according to ISO 14993 – Corrosion of metals and alloys – Accelerated testing involving cyclic exposure to salt mist, “dry” and “wet” conditions [1]. In order to investigate the effect of degree of exposure to environment of inner surface of the pipe on corrosion behavior of inner surface of the specimens, degree of completeness of weldment, 0%, 50%, 80%, and 100%, of steel cover plate is varied. Exposure times in this study are 168, 336, and 504 hours which can be correlated to 10, 20, and 30 years exposed to C3 corrosivity category according to the definition of ISO 9223 – Corrosion of metals and alloys – Corrosivity of atmospheres – Classification, determination and estimation [2,3]. After testing, visual inspection on outer and inner surfaces of the specimens were performed. In addition, average corrosion rate of the specimens were performed according to ISO 8407 – Corrosion of metals and alloys – Removal of corrosion products from corrosion test specimens [4]. The results show that as-received steel pipe specimens exhibited great degree of corrosion attack on the inner surface of the specimens while slight amount of corrosion was observed from the welded pipe specimens.

Effect of Plasma Interface Treatment and Cathodic Electrophoretic Coating on Mg Alloys

2009 ◽  
Vol 610-613 ◽  
pp. 984-990
Author(s):  
Jin Zhang ◽  
Ren Yu Li ◽  
Qing Song Yu
Keyword(s):  
Plasma Polymerization ◽  
Salt Spray ◽  
Corrosion Current ◽  
Mg Alloy ◽  
Electrophoretic Coating ◽  
Aqueous Environments ◽  
Noticeable Reduction ◽  
Dry And Wet Conditions ◽  
Paint Removal ◽  
Interface Treatment

In this study, plasma treatment using Ar and H2 and plasma polymerization with trimethylsilane (TMS), were carried out to create the interface film systems with a structure of Mg/plasma interlayer/cathodic electrophoretic coating (E-coat) for a magnesium (Mg) alloy AZ31B. The interface adhesion of the coating system was evaluated using N-methylpyrrolidinone (NMP) paint removal test and ASTM tape test conducted under dry and wet conditions. Plasma TMS film could stick the Mg substrate more strongly than E-coat.The surface of samples with different interlayer treatment after NMP test has been observed by SEM. The potentiodynamic study performed on the E-coated samples showed a noticeable reduction of corrosion current, three orders of magnitude less than bare Mg. Salt spray test also was done to confirm the resistance corrosion of E-coat. It was found that plasma interface treatment has the ability of increasing the adhesion of E-coat on Mg alloy more or less, thus restrict access to damaging species that exist in Cl- aqueous environments.

Some Applications of the U. S. Steel MVEM

1973 ◽  
Vol 31 ◽  
pp. 4-5
Author(s):  
J. S. Lally ◽  
L. E. Thomas ◽  
R. M. Fisher
Keyword(s):  
Electron Diffraction ◽  
Debye Temperature ◽  
Metals And Alloys ◽  
Critical Voltage ◽  
Dynamical Diffraction ◽  
Phase Structures ◽  
Structure Factors ◽  
Local Bonding ◽  
Diffraction Phenomenon ◽  
Multi Phase

A variety of materials containing many different microstructures have been examined with the USS MVEM. Three topics have been selected to illustrate some of the more recent studies of diffraction phenomena and defect, grain and multi-phase structures of metals and minerals.(1) Critical Voltage Effects in Metals and Alloys - This many-beam dynamical diffraction phenomenon, in which some Bragg resonances vanish at certain accelerating voltages, Vc, depends sensitively on the spacing of diffracting planes, Debye temperature θD and structure factors. Vc values can be measured to ± 0.5% in the HVEM ana used to obtain improved extinction distances and θD values appropriate to electron diffraction, as well as to probe local bonding effects and composition variations in alloys.

Physical, Chemical, and Crystallographic Characterization of Anodic Coatings on High Strength Aluminum Base Alloys

1976 ◽  
Vol 34 ◽  
pp. 636-637
Author(s):  
R. E. Herfert ◽  
N. T. McDevitt
Keyword(s):  
Sulfuric Acid ◽  
Salt Spray ◽  
High Strength ◽  
Environmental Stability ◽  
Anodic Films ◽  
Sodium Dichromate ◽  
Corrosion Resistant ◽  
Aerospace Applications ◽  
Bond Strengths ◽  
Adhesive Bonded Joints

Durability of adhesive bonded joints in moisture and salt spray environments is essential to USAF aircraft. Structural bonding technology for aerospace applications has depended for many years on the preparation of aluminum surfaces by a sulfuric acid/sodium dichromate (FPL etch) treatment. Recently, specific thin film anodizing techniques, phosphoric acid, and chromic acid anodizing have been developed which not only provide good initial bond strengths but vastly improved environmental durability. These thin anodic films are in contrast to the commonly used thick anodic films such as the sulfuric acid or "hard" sulfuric acid anodic films which are highly corrosion resistant in themselves, but which do not provide good initial bond strengths, particularly in low temperature peel.The objective of this study was to determine the characteristics of anodic films on aluminum alloys that make them corrosion resistant. The chemical composition, physical morphology and structure, and mechanical properties of the thin oxide films were to be defined and correlated with the environmental stability of these surfaces in humidity and salt spray. It is anticipated that anodic film characteristics and corrosion resistance will vary with the anodizing processing conditions.

ELECTRONIC RELAXATION IN RARE EARTH METALS AND ALLOYS - A NON-KRAMERS EXAMPLE : Tm3+

1980 ◽  
Vol 41 (C1) ◽  
pp. C1-25-C1-31 ◽  
Author(s):  
N. S. Dixon ◽  
L. S. Fritz ◽  
Y. Mahmud ◽  
B. B. Triplett ◽  
S. S. Hanna ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Metals And Alloys ◽  
Electronic Relaxation

The effective Curie-Weiss constant of ferromagnetic metals and alloys

1962 ◽  
Vol 23 (10) ◽  
pp. 729-729
Author(s):  
E.P. Wohlfarth ◽  
P. Rhodes
Keyword(s):  
Metals And Alloys ◽  
Weiss Constant ◽  
Ferromagnetic Metals
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