Reversible hydrogen trapping in a 3.5NiCrMoV medium strength steel

et al. 2016

Corrosion Science

Self Cite

Please cite this article in press as: J. Venezuela, et al., Influence of hydrogen on the mechanical and fracture properties of some martensitic advanced high strength steels in simulated service conditions, Corros. Sci. (2016), http://dx. a b s t r a c tThis work investigated the influence of hydrogen on the mechanical and fracture properties of four martensitic advanced high-strength steels in simulated service conditions: (i) immersed in 3.5 wt% NaCl solution, and (ii) at substantial applied stress rates. There was little influence of hydrogen for the four MS-AHSS in 3.5 wt% NaCl. Similarly, there was little influence of hydrogen for hydrogen-precharged MS1300 and MS1500 subjected to tensile tests at substantial stress rates. The diffusivities of hydrogen in MS980, MS1300 and MS1500 were similar. The use of a Pt counter electrode during cathodic hydrogen charging is not recommended.

Section: Diffusible Hydrogen Concentrationmentioning

confidence: 97%

Section: Diffusible Hydrogen Concentrationmentioning

confidence: 99%

Influence of hydrogen on the mechanical and fracture properties of some martensitic advanced high strength steels in simulated service conditions

Venezuela

Zhou²,

et al. 2016

Corrosion Science

Self Cite

“…There was a significant increase in hydrogen entering the specimen for about 48 h until a quasi-stable surface condition was reached on the input side. The specimen was pure Fe as annealed low interstitial steel [4,5,10]. Figure 4 shows a succession of hydrogen permeation transients measured with increasing and decreasing hydrogen fugacity, by charging at various potentials in 0.1 M NaOH solution, for pure Fe hydrogen pre-charged at −1.500 VAg/AgCl in 0.1 M NaOH solution for 48 h to achieve steady state surface conditions on the input side.…”

Section: Permeation Cellmentioning

confidence: 99%

“…H-charging conditions are established on the left side of the specimen in the electrochemical permeability cell [4,5]. The amount of H exiting the right hand side is measured as a current.…”

Section: Hydrogen Characterizationmentioning

confidence: 99%

Influence of Hydrogen on Steel Components for Clean Energy

Atrens

Tapia-Bastidas

et al. 2018

CMD

Self Cite

The influence of hydrogen on the mechanical properties of four, medium-strength, commercial, quenched-and-temped steels has been studied using the linearly increasing stress test (LIST) combined with cathodic hydrogen charging. The relationship was established between the equivalent hydrogen pressure and the hydrogen charging overpotential during cathodic hydrogen charging, though the use of electrochemical permeation experiments and thermal desorption spectroscopy. The cathodic hydrogen charging conditions were equivalent to testing in gaseous hydrogen at hydrogen fugacities of over a thousand bar. Under these hydrogen-charging conditions, there was no effect of hydrogen up to the yield stress. There was an influence of hydrogen on the final fracture, which occurred at the same stress as for the steels tested in air. The influence of hydrogen was on the details of the final fracture. In some cases, brittle fractures initiated by hydrogen, or DHF: Decohesive hydrogen fracture, initiated the final fracture of the specimen, which was largely by ductile micro-void coalescence (MVC), but did include some brittle fisheye fractures. Each fisheye was surrounded by MVC. This corresponds to MF: Mixed fracture, wherein a hydrogen microfracture mechanism (i.e., that producing the fisheyes) competed with the ductile MVC fracture. The fisheyes were associated with alumina oxide inclusion, which indicated that these features would be less for a cleaner steel. There was no subcritical crack growth. There was essentially no influence of hydrogen on ductility for the hydrogen conditions studied. At applied stress amplitudes above the threshold stress, fatigue initiation, for low cycle fatigue, occurred at a lower number of cycles with increasing hydrogen fugacity and increasing stress amplitude. This was caused by a decrease in the fatigue initiation period, and by an increase in the crack growth rate. In the presence of hydrogen, there was flat transgranular fracture with vague striations with some intergranular fracture at lower stresses. Mechanical overload occurred when the fatigue crack reached the critical length. There was no significant influence of hydrogen on the final fracture.

“…Hydrogen traps are generally classified as reversible and irreversible traps depending on their binding energy with hydrogen atoms [5,6]. A reversible trap is one from which a hydrogen atom can easily jump out of due to fluctuations in thermal energy [7]. It is known that grain boundaries, dislocations, vacancies, and microvoids have low binding energy with hydrogen atoms and are considered as reversible traps.…”

Section: Introductionmentioning

confidence: 99%

Effect of Batch Annealing Temperature on Microstructure and Resistance to Fish Scaling of Ultra-Low Carbon Enamel Steel

Kang

Zhang

et al. 2017

Metals

Abstract:In the present work, an ultra-low carbon enamel steel was batch annealed at different temperatures, and the effect of the batch annealing temperature on the microstructure and resistance to fish scaling was investigated by optical microscopy, transmission electron microscopy, and a hydrogen permeation test. The results show that the main precipitates in experimental steel are fine TiC and coarse Ti 4 C 2 S 2 particles. The average sizes of both TiC and Ti 4 C 2 S 2 increase with increasing the batch annealing temperature. The resistance to fish scaling decreases with increasing the annealing temperature, which is caused by the growth of ferrite grain and the coarsening of the TiC and Ti 4 C 2 S 2 particles.