Some Effects of Strain Rate on the Transgranular Stress Corrosion Cracking of Ferritic Steels in Dilute Near-Neutral-pH Solutions

Parkins, R. N.; Beavers, J.A.

doi:10.5006/1.3277559

Cited by 61 publications

(39 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At lower ∆Ks, the data tended to a constant crack growth rate, independent of ∆K, and corresponded to the SCC growth rate divided by the frequency, given in eqn. (2). The SCC time dependent component was 2.94x10 -9 mm/s.…”

Section: Superposition Modelmentioning

confidence: 99%

“…This form of EAC which appears to be insensitive to temperature has been observed under the disbonded region of the pipeline coating where cathodic protection is not effective. Hydrogen assisted cracking due to the cathodic reaction at the crack tip and subsequent entry into the steel has been identified as the active mechanism [1,2]. TGSCC is termed "near neutral SCC" since it is uniquely different from intergranular SCC that is observed in concentrated carbonate/bicarbonate electrolytes of high pH (~10) at slightly elevated temperatures [3].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modelling environmentally assisted cracking in pipeline steels

Plumtree¹,

Lambert²

2007

WIT Transactions on Engineering Sciences, Vol 54

View full text Add to dashboard Cite

An investigation has been conducted on the environmentally assisted cracking (EAC) of ferritic-pearlitic pipeline steels in contact with simulated groundwater. The loading and environmental conditions were similar to those for buried natural gas pipelines in service. An anaerobic, dilute near-neutral pH solution was used in conjunction with the open-circuit potential for this system. The intent of this work was to determine and model the growth rate of environmentally assisted cracks in the form of transgranular stress corrosion cracks (TGSCC) that have been observed following field investigations. Combinations of low frequency cycling and high stress ratio R (=minimum load/maximum load), can produce transgranular fracture and a quantitative relationship between these two parameters has been developed for the conditions under which TGSCC takes place. The recorded crack growth rates were similar to those in the field and a superposition model was applied to the experimental data, giving good agreement between the observed and predicted single crack growth rates. Applying the superposition model to operating natural gas pipeline data indicated that more realistic predictions of crack growth would result by considering the interaction of multiple cracks, as observed in the field colonies.

show abstract

Section: Superposition Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modelling environmentally assisted cracking in pipeline steels

Plumtree¹,

Lambert²

2007

WIT Transactions on Engineering Sciences, Vol 54

View full text Add to dashboard Cite

show abstract

“…Evaluations of hydrogen permeation on the materials determine the effect of solutions in the transport of hydrogen by diffusion, and these effects could get the possibility to cause structural damage in materials, mainly by over loading conditions. Many authors have studied the hydrogen permeation and its effect in the susceptibility of embrittlement on different materials such as the welded stainless steel [1], 17-4PH type stainless steel [2] and a duplex stainless steel [3], where the consequences of hydrogen ingress were mainly loss of plasticity and deterioration of mechanical properties over all different microstructural phases present in these materials. Some others have carried out hydrogen permeation on pure materials and compound alloys [4][5][6][7], but just a few investigations were done on iron and low carbon steels [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

“…However, these researches were developed on pipeline body and did not include the welding zone. The slow strain rate testing (SSRT) technique is widely used to study both crack initiation and growth [1][2][3][4][5][6][7][8], however, one of its main uses is to identify alloys that should not experience SCC in service. Thus, this work is not dealing with the crack initiation or crack growth, but with the SCC susceptibility of welded X-52 and X-60 pipeline steels in …”

Section: Introductionmentioning

confidence: 99%

SCC of X‐52 and X‐60 weldements in diluted NaHCO₃ solutions with chloride and sulfate ions

Espinosa-Medina

Ángeles–Chávez

Zeferino-Rodriguez

2007

Materials & Corrosion

View full text Add to dashboard Cite

Stress corrosion cracking tests were performed in both X-52 and X-60 weldments in sodium bicarbonate (NaHCO 3 ) solutions at 50 C using the Slow Strain Rate Testing (SSRT) technique. Solution concentrations varied between 0.1 to 0.0001 M, and to simulate the NS-4 solution, chloride (Cl À ) and/or sulfate (SO 2À 4 ) ions were added to the 0.01 M solution. Tests were complemented with hydrogen permeation measurements and polarization curves. It was found that the corrosion rate, taken as the corrosion current, I corr , was maximum in 0.01 M NaHCO 3 and with additions of SO 2À 4 ions. Higher or lower solution concentrations or additions of Cl À alone decreased the corrosion rate of the weldment. The SSC susceptibility, measured as the percentage reduction in area, was maximum in 0.01M NaHCO 3 . Higher or lower solution concentrations of additions of Cl À or SO 2À 4 decreased the SCC susceptibility of the weldment. The amount of hydrogen uptake for the weldment was also highest in 0.01 M NaHCO 3 solution, but it was minimum with the addition of Cl À or SO 2À 4 ions. Thus, the most likely mechanism for the cracking susceptibility of X-52 and X-60 weldments in diluted NaHCO 3 solutions seems to be hydrogen-assisted anodic dissolution.

show abstract

“…NS4 synthetic solution has been widely used to simulate the soil solution in the study of near neutral pH-SCC behavior. However, another synthetic soil solution called NS1, NS2, NS3, NS4, NOVA and C1 has been used in similar studies [22][23][24][25] . Table 2 shows the chemical composition of the NS4 solution used.…”

Section: Test Solutionmentioning

confidence: 99%

Electrochemical Noise for Detection of Stress Corrosion Cracking of Low Carbon Steel Exposed to Synthetic Soil Solution

2017

View full text Add to dashboard Cite

In the last years, electrochemical noise (EN) has demonstrate that is capable of detect the initiation of cracks during the slow strain rate tests (SSRT). In this research, EN has been used as a tool to detect stress corrosion cracking (SCC) in low carbon steel (X52) exposed to a synthetic soil solution called NS4 at room temperature with pH of 5, 8 and 10. The electrochemical potential and current noise were measured simultaneously during SSRT. Relation between EN and SCC process was analyzed. EN readings of current consisted of transients with high intensity and frequency during all SSRT tests. EN readings of potential at the maximum strength (UTS) and before fracture, increase intensity and amplitude of the transients, attributed to beginning of cracking. Localized index (LI) values indicate a mix corrosion type (general and localized corrosion) during SSRT tests. According to SCC index obtained from mechanical properties, it is clear that X52 steel has low SCC susceptibility. Scanning electron microscopy (SEM) observations were carried out in the fracture surface and longitudinal sections. The specimens tested in NS4 solution with pH 5 were the most likely to present SCC, additionally in this condition a brittle fracture with transgranular appearance was observed.

show abstract

Some Effects of Strain Rate on the Transgranular Stress Corrosion Cracking of Ferritic Steels in Dilute Near-Neutral-pH Solutions

Cited by 61 publications

References 3 publications

Modelling environmentally assisted cracking in pipeline steels

Modelling environmentally assisted cracking in pipeline steels

SCC of X‐52 and X‐60 weldements in diluted NaHCO₃ solutions with chloride and sulfate ions

Electrochemical Noise for Detection of Stress Corrosion Cracking of Low Carbon Steel Exposed to Synthetic Soil Solution

Contact Info

Product

Resources

About

Some Effects of Strain Rate on the Transgranular Stress Corrosion Cracking of Ferritic Steels in Dilute Near-Neutral-pH Solutions

Cited by 61 publications

References 3 publications

Modelling environmentally assisted cracking in pipeline steels

Modelling environmentally assisted cracking in pipeline steels

SCC of X‐52 and X‐60 weldements in diluted NaHCO3 solutions with chloride and sulfate ions

Electrochemical Noise for Detection of Stress Corrosion Cracking of Low Carbon Steel Exposed to Synthetic Soil Solution

Contact Info

Product

Resources

About

SCC of X‐52 and X‐60 weldements in diluted NaHCO₃ solutions with chloride and sulfate ions