Effects of pre-oxidation on the corrosion behavior of pure Ti under coexistence of solid NaCl deposit and humid oxygen at 600 °C: the diffusion of chlorine

Abstract The effect of pre-oxidation on the corrosion behavior of pure Ti covered with a solid NaCl deposit in the humid O2 flow at 600 °C is studied. The oxide scale, formed by pre-oxidation, protects the substrate from the NaCl induced corrosion during the initial stage. However, the corrosion of the pre-oxidized sample is severely accelerated by solid NaCl after an incubation period. The chlorine, generated from the decomposition of solid NaCl, diffuses into the oxide/substrate interface as ions during the incubation period, which was observed by ToF–SIMS. The chlorine at the oxide/substrate interface induces the fast corrosion after the incubation period although the pre-oxidation scale is complete and compact.

Download Full-text

A Chemomechanical Model for Stress Evolution and Distribution in the Viscoplastic Oxide Scale During Oxidation

Journal of Applied Mechanics ◽

10.1115/1.4032796 ◽

2016 ◽

Vol 83 (5) ◽

Cited By ~ 5

Author(s):

Hailong Wang ◽

Shengping Shen

Keyword(s):

Oxide Scale ◽

Maximum Stress ◽

Stress Gradient ◽

Oxidation Time ◽

Stress Evolution ◽

Oxide Interface ◽

Temperature Oxidation ◽

Substrate Interface ◽

Oxide Substrate ◽

Chemomechanical Model

Using the location-dependent growth strain, a chemomechanical model is developed for the analysis of the stress evolution and distribution in the viscoplastic oxide scale during high-temperature oxidation. The problem of oxidizing a semi-infinite substrate is formulated and solved. The numerical results reveal high compressive stress and significant stress gradient. The maximum stress is at the oxide/substrate interface and the minimum stress at the oxygen/oxide interface in short oxidation time, while the maximum stress is no longer at the oxide/substrate interface in long oxidation time. The stress evolutions at different locations are also presented. The predicted results agree well with the experimental data.

Download Full-text

Effect of Oxide Scale Microstructure on Atmospheric Corrosion Behavior of Hot Rolled Steel Strip

Coatings ◽

10.3390/coatings11050517 ◽

2021 ◽

Vol 11 (5) ◽

pp. 517

Author(s):

Bin Sun ◽

Lei Cheng ◽

Chong-Yang Du ◽

Jing-Ke Zhang ◽

Yong-Quan He ◽

...

Keyword(s):

Corrosion Resistance ◽

Oxide Scale ◽

Corrosion Product ◽

Corrosion Behavior ◽

Corrosion Test ◽

Atmospheric Corrosion ◽

Corrosion Mechanism ◽

Type I ◽

Rust Layer ◽

Hot Rolled

The atmospheric corrosion behavior of a hot-rolled strip with four types (I–IV) of oxide scale was investigated using the accelerated wet–dry cycle corrosion test. Corrosion resistance and porosity of oxide scale were studied by potentiometric polarization measurements. Characterization of samples after 80 cycles of the wet–dry corrosion test showed that scale comprised wüstite and magnetite had strongest corrosion resistance. Oxide scale composed of inner magnetite/iron (>70%) and an outer magnetite layer had the weakest corrosion resistance. The corrosion kinetics (weight gain) of each type of oxide scale followed an initial linear and then parabolic (at middle to late corrosion) relationship. This could be predicted by a simple kinetic model which showed good agreement with the experimental results. Analysis of the potentiometric polarization curves, obtained from oxide coated steel electrodes, revealed that the type I oxide scale had the highest porosity, and the corrosion mechanism resulted from the joint effects of electrochemical behavior and the porosity of the oxide scale. In the initial stage of corrosion, the corrosion product nucleated and an outer rust layer formed. As the thickness of outer rust layer increased, the corrosion product developed on the scale defects. An inner rust layer then formed in the localized pits as crack growth of the scale. This attacked the scale and expanded into the substrate during the later stage of corrosion. At this stage, the protective effect of the oxide scale was lost.

Download Full-text

An electrical study of behaviors of Si nanocrystals distributed in the gate oxide near the oxide/substrate interface of a MOS structure

Thin Solid Films ◽

10.1016/j.tsf.2005.09.035 ◽

2006 ◽

Vol 504 (1-2) ◽

pp. 32-35

Author(s):

C.Y. Ng ◽

G.S. Lum ◽

S.C. Tan ◽

T.P. Chen ◽

L. Ding ◽

...

Keyword(s):

Gate Oxide ◽

Mos Structure ◽

Substrate Interface ◽

Si Nanocrystals ◽

Oxide Substrate ◽

Electrical Study

Download Full-text

Effect of Deformation on the Corrosion Behavior of Chromium Bronze

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.303-306.2465 ◽

2013 ◽

Vol 303-306 ◽

pp. 2465-2468

Author(s):

Ya Ni Zhang ◽

Dang Hui Wang ◽

Tian Han Xu

Keyword(s):

Corrosion Resistance ◽

Mass Loss ◽

Corrosion Behavior ◽

Initial Stage ◽

Corrosion Scales ◽

Rolled Specimen ◽

Cold Rolled ◽

Chromium Bronze ◽

Cold Worked ◽

Cold Rolled Specimen

The service life of material is much related with its corrosion resistance. Thus, the investigation on corrosion behavior is important for the better use of material. In this paper, the corrosion behavior of deformed chromium bronze experienced different processing was investigated in NaCl environment using electrochemical measurements and mass-loss tests. It has showed that the potentiodynamic polarization curves of cold rolled specimen coincide with that of cold worked specimen in two concentration of NaCl solution. The last cold working has little effect on the electrochemical behavior of cold rolled chromium bronze.The NaCl fog experiment showed that the corrosion resistance of cold rolled specimen is slightly better than that of cold worked specimen, and the mass-loss for two kinds of specimen are similar in the initial stage but the gap is increasing with corrosion time. The corrosion scales on the surface of specimen, accumulated in the form of island produced in the NaCl fog experiment , has little hindered effect on corrosion behavior.

Download Full-text

Studies on corrosion behavior of a single-crystal superalloy and its sputtered nanocrystalline coatings with solid NaCl deposit in O2 + 38 vol.% H2O environment at 700 °C

Corrosion Science ◽

10.1016/j.corsci.2019.108187 ◽

2019 ◽

Vol 161 ◽

pp. 108187 ◽

Cited By ~ 1

Author(s):

Wenyao Sun ◽

Jinlong Wang ◽

Lanlan Yang ◽

Minghui Chen ◽

Zebin Bao ◽

...

Keyword(s):

Single Crystal ◽

Corrosion Behavior ◽

Single Crystal Superalloy ◽

Nacl Deposit

Download Full-text

Oxidation of Strained Si-Ge Layers Grown by MBE

MRS Proceedings ◽

10.1557/proc-102-295 ◽

1987 ◽

Vol 102 ◽

Cited By ~ 30

Author(s):

G.L. Patton ◽

S.S. Iyer ◽

S.L. Delage ◽

E. Ganin ◽

R.C. Mcintosh

Keyword(s):

Growth Rate ◽

Molecular Beam Epitaxy ◽

Epitaxial Layer ◽

Molecular Beam ◽

Fast Growth ◽

Strained Si ◽

Substrate Interface ◽

Growth Regime ◽

Oxide Substrate ◽

Strained Sige

ABSTRACTThe oxidation of strained SiGe alloy layers grown by Molecular Beam Epitaxy (MBE) was studied. An initial fast growth regime was identified for 800°C steam oxidations, where the growth rate is 2.5 times that of silicon. The oxides formed on SiGe were found to be essentially Ge-free: Ge present in the material is rejected by the oxide, resulting in the formation of a Ge-rich epitaxial layer at the oxide/substrate interface.

Download Full-text