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(PDF) Study of Electrochemical Behavior, Hydrogen

Dec 01, 2020 · hydrogen distribution, trapping and its diffusion in X70 pipeline steel. It has been found that corrosion behavior of pipeline steel in the sour environment is higher than the near neutral soil 2D modelling of the effect of grain size on hydrogen In order to do this, hydrogen diffusion in both grains and grain boundaries was modelled using Cellular Automaton technique combined with the finite difference method. The simulation was implemented in two-dimensions (2D) in both grains and grain boundaries to highlight the significance of grain boundaries in hydrogen diffusion.

Effect of Microstructure on Hydrogen Diffusion in Weld and

Jan 01, 2017 · [41] V. Olden, A. Alvaro, and O. M. Akselsen, "Hydrogen diffusion and hydrogen influenced critical stress intensity in an API X70 pipeline steel welded joint - Experiments and FE simulations," International Journal of Hydrogen Energy, vol. 37, no. 15, pp. 11474-11486, 2012. Effect of Microstructure on Hydrogen Diffusion in Weld and tested the hydrogen trapping efficiency of API X65 and showed an increase in order of ferrite/degenerated pearlite, ferrite/bainite, and ferrite/acicular ferrite. Haq et al. showed that, due to hydrogen trapping, X70 medium strip exhibits lower hydrogen diffusivity than the standard Mn strip. This is mainly due to finer ferrite grains and a higher density of carbonitride precipitates. Effect of Nanosized NbC Precipitates on Hydrogen Diffusion Jun 28, 2017 · For further study of the effects of NbC as an irreversible trap on hydrogen diffusion, different hydrogen trap types in Nb-bearing steel were designed using different heat treatments [21,22]. According to the TDS curve and T c, three steps of hydrogen permeations were applied as mentioned in Section 2.2.3. In the first step, hydrogen atoms

Effect of microstructure on hydrogen diffusion in X70

hydrogen concentration and corresponding trapping parameters in an X70 grade pipeline steel and its weldments. 2 Basis for Calculations The lattice diffusion coefcient for hydrogen in steel is given by:D l =D0exp E l RT ; (1) where E l =5:69 kJ=mol is the energy barrier for hydrogen jumps between two lattice points and D0 is 7:23 10 4 cm2=s [16]. Effect of thermomechanical processing on hydrogen Electrochemical hydrogen permeation tests were utilized to investigate the diffusion and trapping of hydrogen in API X70 pipeline steel. Thermomechanical processing was used in order to produce 4 samples with different microstructural features. Detailed characterization was Hydrogen diffusion in low alloy steels under cyclic Sep 25, 2019 · The influence of plastic strain on hydrogen diffusion and trapping in weld simulated heat affected zone of X70 pipeline steel. In:Proceedings of Eurocorr, Istanbul, Turkey, 2012. Olden V, Saai A, Jemblie L, Johnsen R. FE simulation of hydrogen diffusion in duplex stainless steel. Int J Hydrogen Energy 2014; 39:11561163. Oriani RA.

Hydrogen-induced cracking susceptibility and hydrogen

Aug 28, 2010 · The rate of hydrogen diffusion in steel is influenced mainly by two factors:one is the concentration of hydrogen at the steel surface, the other is the microstructure. Primary and secondary phases including non-metallic inclusions and precipitates can affect both the hydrogen trapping and diffusion in the steel. Influence of Thermomechanically Controlled Processing on The effect of different thermomechanical controlled processing routes on susceptibility of X70 pipeline steel to hydrogen induced cracking (HIC) have been studied. Two X70 pipeline steel specimens labelled WE and WD were investigated. These specimens have the same chemical composition, but they were processed with seperate thermomechanical treatments parameters. Investigation of hydrogen diffusion and accumulation in However, they occasionally fail leading to environmental pollution, fatalities and financial losses. Pipeline cracking by hydrogen embrittlement is the main cause of pipeline failure. The main focus of this research was on the effect of grain size and misorientation on hydrogen diffusion and accumulation in X70 pipeline steel.

Numerical Evaluation on Analysis Methods of Trapping Site

For example, by analyzing permeation curves, the trapping site density in an X70 steel was examined as 1.3~3.1 × 10 18 /m 3 . However, in another X70 steel, the trapping site density was fitted as 2.81 × 10 27 /m 3 . Such a large difference could be accounted for in the use of incorrect simplified formulas . In this present study, with the The Influence of Plastic Strain on the Effective Hydrogen INTRODUCTIONThe trapping phenomenon of hydrogen in steel has been known, and worked on, for a long time, and according to Oriani, 1970 the first attempt to describe this was done in 1949 by Darken and Smith. Typical trapping sites in steel are dislocations, vacations, grain boundaries, phase boundaries, inclusions and precipitates.Effect of Cold-Rolling on Hydrogen Diffusion and Trapping Jan 13, 2021 · 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.