scholarly journals The Effect of Temperature on the Hydrogen Permeation of Pipeline Steel in Wet Hydrogen Sulfide Environments

Author(s):  
Zhu Wang ◽  
2017 ◽  
Vol 26 (8) ◽  
pp. 3775-3783 ◽  
Author(s):  
Paul C. Okonkwo ◽  
Mostafa H. Sliem ◽  
R. A. Shakoor ◽  
A. M. A. Mohamed ◽  
Aboubakr M. Abdullah

2018 ◽  
Vol 175 ◽  
pp. 01027
Author(s):  
Hai Zhang ◽  
Shaopo Li ◽  
Wenhua Ding ◽  
Ning Hao

Hydrogen sulfide corrosion test was used to test the hydrogen-induced cracking sensitivity of the normalized BNS pipeline steel. The microstructure and morphology of hydrogen induced crack(HIC) of the normalized BNS pipeline steel after hydrogen sulfide corrosion test were observed with optical microscopy(OM), scanning electron microscopy(SEM). Combined with electron probe microanalyzer(EPMA) and hardness test, the hydrogen-induced cracking behavior of BNS pipeline steel was studied from the aspects of microstructure, crack morphology, center segregation and harness. The results showed that the pearlite band with high hardness caused by center segregation of C and Mn was the main crack initiation and propagation path for the long-size and linear shape hydrogen induced crack at the center of plate thickness, and the type of crack propagation was transgranular. Some tiny hydrogen induced crack nucleated from the small calcium-aluminate inclusion and the tiny hydrogen induced crack would not propagate to form long-size cracks with no suitable propagation path existing around the inclusion.


Author(s):  
Alen Thomas ◽  
Jerzy Szpunar

Abstract In this investigation, we prepared samples with five different grain misorientations by cold rolling an X70 pipeline steel plate. The hydrogen permeation and hydrogen visualization experiments were used to compute the diffusion parameters and to reveal the diffusion path in steel samples. The dual-polarized permeation experiment allowed us to show that permeability and effective diffusion coefficient were decreased with an increase in misorientation. Hence, the total and irreversible trapping sites were also raised with the extent of deformation in the steel. On the other hand, the visualization study permitted us to show that hydrogen diffusion intensity changes within the microstructure. The diffusion intensity increases in the order of non-deformed grains, grain boundaries and deformed grains with deformed grains as the easiest path for hydrogen diffusion.


2012 ◽  
Vol 538-541 ◽  
pp. 1724-1731
Author(s):  
Hong Wei Zheng ◽  
Di Tang ◽  
Hui Bin Wu ◽  
Liu Yang

The high-temperature deformation resistance of X120 pipeline steel was studied under different deformation temperature and different deformation rate through the hot compression test on the Gleeble-3500 thermal/mechanics simulation test machine. The influence of deformation degree, deformation temperature and deformation rate on deformation resistance was thoroughly investigated. The deformation resistance of X120 pipeline steel increased slowly when deformation degree was higher than 0.2. With the increase of deformation temperature, the work-hardening effect was weakened, so the deformation resistance decreased. And the deformation rate had dual influences on the deformation resistance, including the effect of temperature and time. Based on the experiment data, the parameters in the mathematical model were regressed by using SPSS (Statistic Package for Social Science), and the mathematical model of the deformation resistance of X120 pipeline steel was established finally. Through the regression analysis, the model had been proved to have great matching precision.


2013 ◽  
Vol 743-744 ◽  
pp. 589-596 ◽  
Author(s):  
Meng Liu ◽  
Jian Qiu Wang ◽  
Wei Ke

The corrosion behavior of X52 pipeline steel in H2S solutions was investigated through immersion corrosion test which was carried out in a high temperature and high pressure autoclave at different temperatures and H2S concentrations. General corrosion rates were calculated based on the weight loss of samples. The morphology and the chemical composition of the corrosion products were obtained by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The crystal structure of corrosion products was analyzed by X-Ray diffraction patterns (XRD). The corrosion products consisted mainly of the sulfide compounds (mackinawite, cubic ferrous sulfide, troilite and pyrrhotite). The corrosion products included two layers: the inner iron-rich layer and the outer sulfur-rich layer. Under H2S concentrations of 27g/L, the corrosion rate increased with the increase of temperature up to 90°C and then decreased at 120°C, finaly increased again. The corrosion rate first increased with H2S concentrations then decreased at 120°C. The structure and stability of the corrosion products due to different corrosion mechanism had a major impact on the corrosion rate. The corrosion resistance of the corrosion products increased as follows: mackinawite < cubic ferrous sulfide < troilite < pyrrhotite.


CORROSION ◽  
1956 ◽  
Vol 12 (1) ◽  
pp. 22-32 ◽  
Author(s):  
E. B. BACKENSTO ◽  
R. D. DREW ◽  
C. C. STAPLEFORD

Abstract High temperature hydrogen sulfide corrosion of carbon steel and low chrome alloys has become a serious problem in the petroleum industry in connection with the increasing use of high pressure hydrogenation and dehydrogenation processes for upgrading petroleum fractions. The effect of temperature, pressure and hydrogen sulfide concentration on the corrosion rate of a wide range of commonly used carbon steels and alloys has been determined in laboratory tests. It has been established that the low chrome alloys (up to 5 percent chromium) which have been used to combat sulfur corrosion in fractionation and cracking equipment, show little or no advanage over carbon steel in resisting attack by hydrogen sulfide. Of the conventional alloy steels tested, only the 18-8 chrome nickel and higher alloys have shown good resistance to this type of corrosion over a wide range of pressure, temperature and hydrogen sulfide concentration. It was found that aluminum coated steels also showed very good corrosion resistance. Three methods were proposed for minimizing hydrogen sulfide corrosion: (1) Reduction of hydrogen sulfide in process streams, (2) Use of chrome-nickel alloys, and (3) Protection of metals by aluminum coating.


Author(s):  
Weixing Chen ◽  
Sheng-Hui Wang ◽  
Fraser King ◽  
Tom R. Jack ◽  
Martyn J. Wilmott

This paper reports the hydrogen permeation behavior of an X-70 pipeline steel in a synthetic near neutral pH field solution under both galvanostatic and potentiostatic conditions. The hydrogen flux through the steel exposed to the solution is influenced by the chemical reactions at the steel surface on the charging side. Results from tests done under potentiostatic and galvanostatic conditions were compared to predictions based on different boundary conditions assumed in solving Fick’s diffusion equations. Constant concentration boundary conditions gave the best fit. It was also found that the diffusible hydrogen generated in a near neutral pH soil environment is likely to be 3 to 10 times lower than the minimum hydrogen concentration required to initiate hydrogen blistering in pipeline steels.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
R. C. Souza ◽  
L. R. Pereira ◽  
L. M. Starling ◽  
J. N. Pereira ◽  
T. A. Simões ◽  
...  

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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