Influence of Zn-based Coating Alloys on Hydrogen Diffusion and Corrosion Resistance in a DP Steel

2021 ◽

Vol 45 (1) ◽

pp. 69-74

Author(s):

Tassi Hocine ◽

Zidelmel Sami ◽

Allaoui Omar

Keyword(s):

Corrosion Resistance ◽

Dual Phase Steel ◽

Annealing Temperature ◽

Intercritical Annealing ◽

Ferrite Matrix ◽

Dual Phase ◽

H2so4 Solution ◽

Dp Steel ◽

Direct Quenching ◽

Step Quenching

In the present investigation, some electrochemical properties of dual phase X70 steels with different martensite morphologies which have undergone boriding were studied. To obtain a variety of martensite morphologies, Direct Quenching (DQ), Intermediate Quenching (IQ) and Step Quenching (SQ) heat treatments were applied at an intercritical annealing temperature (IAT) of 760℃. The treatment (DQ) allowed the formation of fine martensite evenly distributed in the ferrite matrix. (IQ) treatment showed the formation of martensite along the ferrite / ferrite grain boundaries. In contrast, treatment (SQ) induced the formation of a banded morphology of martensite and ferrite. The realization of borides on X70 (DP) steel was carried out in a powder mixture containing 5% of B4C as source of boron, 5% of NaBF4 as activator and 90% of SiC as diluent at 950℃ for a period of time from 4 h. The corrosion behavior of X70 (DP) steel has been explored by the Tafel extrapolation method in a 5 wt. % H2SO4 solution. The corrosion resistance of steel which has undergone boriding (BDP) is higher than that of steel which has not undergone it (DP).

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Microstructural Characterization and Corrosion-Resistance Behavior of Dual-Phase Steels Compared to Conventional Rebar

Crystals ◽

10.3390/cryst10111068 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1068

Author(s):

Hany S. Abdo ◽

Asiful H. Seikh ◽

Biplab Baran Mandal ◽

Jabair A. Mohammed ◽

Sameh A. Ragab ◽

...

Keyword(s):

Corrosion Resistance ◽

Galvanic Corrosion ◽

Microstructural Characterization ◽

Carbon Steels ◽

Dual Phase ◽

Low Carbon ◽

Dp Steel ◽

Dp Steels ◽

Superior Corrosion Resistance ◽

Corrosive Environments

Dual-phase (DP) steels consist of a ferritic matrix dispersed with some percentage of martensite, which gives the material a good combination of strength and ductility, along with the capacity to absorb energy and enhanced corrosion protection properties. The purpose of this work was to study the microstructural and corrosion behavior (mainly pitting and galvanic corrosion) of DP steel compared with that of conventional rebar. To obtain DP steel, low-carbon steels were heat-treated at 950 °C for 1 h and then intercritically annealed at 771 °C for 75 min, followed by quenching in ice-brine water. The corrosion rates of DP steel and standard rebar were then measured in different pore solutions. Macro- and microhardness tests were performed for both steels. It was found that DP steels exhibited a superior corrosion resistance and strength compared to standard rebar. The reported results show that DP steels are a good candidate for concrete reinforcement, especially in aggressive and corrosive environments.

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Effect of Microstructure on Hydrogen Diffusion in Weld and API X52 Pipeline Steel Base Metals under Cathodic Protection

International Journal of Corrosion ◽

10.1155/2017/4927210 ◽

2017 ◽

Vol 2017 ◽

pp. 1-14 ◽

Cited By ~ 1

Author(s):

R. C. Souza ◽

L. R. Pereira ◽

L. M. Starling ◽

J. N. Pereira ◽

T. A. Simões ◽

...

Keyword(s):

Corrosion Resistance ◽

Weld Metal ◽

Base Metal ◽

Cathodic Protection ◽

Hydrogen Diffusion ◽

Hydrogen Permeation ◽

Pipeline Steel ◽

Sodium Thiosulfate ◽

Hydrogen Flow ◽

Electrochemical Tests

The aim of this research was to evaluate the influence of microstructure on hydrogen permeation of weld and API X52 base metal under cathodic protection. The microstructures analyzed were of the API X52, as received, quenched, and annealed, and the welded zone. The test was performed in base metal (BM), quenched base metal (QBM), annealed base metal (ABM), and weld metal (WM). Hydrogen permeation flows were evaluated using electrochemical tests in a Devanathan cell. The potentiodynamic polarization curves were carried out to evaluate the corrosion resistance of each microstructure. All tests were carried out in synthetic soil solutions NS4 and NS4 + sodium thiosulfate at 25°C. The sodium thiosulfate was used to simulate sulfate reduction bacteria (SRB). Through polarization, assays established that the microstructure does not influence the corrosion resistance. The permeation tests showed that weld metal had lower hydrogen flow than base metal as received, quenched, and annealed.

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Fractographic analysis of the role of hydrogen diffusion on the hydrogen embrittlement susceptibility of DP steel

Materials Science and Engineering A ◽

10.1016/j.msea.2015.09.124 ◽

2016 ◽

Vol 649 ◽

pp. 201-208 ◽

Cited By ~ 61

Author(s):

T. Depover ◽

E. Wallaert ◽

K. Verbeken

Keyword(s):

Hydrogen Embrittlement ◽

Hydrogen Diffusion ◽

Fractographic Analysis ◽

Dp Steel

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Microstructures of Ti-1.5 w/o Ni Alloys with Mo and A1 Additions

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100113895 ◽

1975 ◽

Vol 33 ◽

pp. 54-55

Author(s):

Anna C. Fraker

Keyword(s):

Corrosion Resistance ◽

Beneficial Effect ◽

Crevice Corrosion ◽

Local Corrosion ◽

Precipitate Size ◽

Ni Alloys

Small amounts of nickel are added to titanium to improve the crevice corrosion resistance but this results in an alloy which has sheet fabrication difficulties and is subject to the formation of large Ti2Ni precipitates. These large precipitates can serve as local corrosion sites; but in a smaller more widely dispersed form, they can have a beneficial effect on crevice corrosion resistance. The purpose of the present work is to show that the addition of a small amount of Mo to the Ti-1.5Ni alloy reduces the Ti2Ni precipitate size and produces a more elongated grained microstructure. It has recently been reported that small additions of Mo to Ti-0.8 to lw/o Ni alloys produce good crevice corrosion resistance and improved fabrication properties.

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