The influence of external and internal factors on stress corrosion cracking of low-alloyed pipe steel

Authors

  • L. I. Nyrkova

DOI:

https://doi.org/10.31471/2311-1399-2020-1(13)-8-15

Keywords:

alternating wetting; cathodic polarization; low alloyed pipe steel; near-neutral environment; slow strain rate test; stress-corrosion cracking.

Abstract

The article presents investigation results of the regularities of stress corrosion cracking (SCC) of controllable rolling X70
pipeline steel under the influence of various factors: corrosion-active environment, potential, pre-accumulated stresses, periodic wetting, etc. Factors, acting in the conditions of the gas pipe mains operation, were simulated in the laboratory conditions and their influence on the SCC susceptibility of X70 pipe steel was investigated. It was found that in NS4 solution, potential shifting to the cathode area promotes the increasing of the SCC susceptibility of X70 steel. Under cathodic protection at potential equal to -1.0 V, the fracture characteristics change, a brittle component appears in the fracture, and the coefficient KS increases compared to the breaking of samples without cathodic potential. Under such a potential there may appear some differences in the SCC susceptibility of X70 steel, which have a minor structural features: steel with less contamination of non-metallic inclusions is less susceptible to brittle cracking. Accumulated cyclic stresses, periodic wetting, the presence of coatings with different transient resistance and the stress concentrator promote the increase of the degree of SCC susceptibility of X70 pipeline steel at a potential of -1.0 V.

Downloads

Download data is not yet available.

References

Stress corrosion cracking. URL :

https://www.slideshare.net/SHIВAJICHOUDHURY/damagemechanism-

in-boiler-thermal-power-plant (the date of access

02.2020)

Glazov, NP, Glazov, NG & Bashaev, MA 2009,

‘The influence of the insulation state of pipelines on the rate of

their corrosion failure’, Pipeline transport (theory and

practice), no 1, pp. 47–49.

Maocheng, Y, Wang, J, Han, E & Ke, W 2008,

‘Local environment under simulated disbonded coating on

steel pipelines in soil solution’, Corrosion Science, vol. 50,

iss. 5, pp. 1331–1339.

Eslami, A at all 2010, ‘Stress corrosion cracking

initiation under the disbonded coating of pipeline steel in nearneutral

pH environment’, Corrosion Science, vol. 52, iss. 11,

pp. 3750–3756.

Harris, NA, Ismagilov, NG & Bakhtegareeva, AN

, ‘Changes in the thermophysical characteristics of soil

around a large-diameter gas pipeline as a reason for the

intensification of corrosion processes’, Oil and Gas Business,

iss. 1, pp. 1–9. URL: http://www.ogbus.ru. 2010.

Liu, ZY, Li, XG, Du, CW & Cheng, YF 2009, ‘Local

additional potential model for effect of strain rate on SCC of

pipeline steel in an acidic soil solution’, Corrosion Science,

vol. 51, iss. 12, pp. 2863–2871.

Liu, ZY, Li, XG, Du, CW, Zhai, GL & Cheng, YF

, ‘Stress corrosion cracking behavior of X70 pipe steel in

an acidic soil environment’, Corrosion Science, vol. 50, iss. 8,

pp. 2251–2257.

Fu, AQ, Tang, X & Cheng, YF 2009,

‘Characterization of corrosion of X70 pipeline steel in thin

electrolyte layer under disbonded coating by scanning Kelvin

probe’, Corrosion Science, vol. 51, iss. 1, pp. 186–190.

Liu, ZY, Li, NG & Cheng, YF 2012, ‘Mechanistic

aspect of near-neutral pH stress corrosion cracking of

pipelines under cathodic polarization’, Corrosion Science,

vol. 55, iss. 2, pp. 54–60.

Shipilov, SA & Le May, I 2006, ‘Structural

integrity of aging buried pipelines having cathodic protection’,

Engineering Failure Analysis, no 13, pp. 1159–1176.

Fu, AQ & Cheng, YF 2010, ‘Electrochemical

polarization behaВior of X70 steel in thin

carbonate/bicarbonate solution layers trapped under a

disbonded coating and its implication on pipeline SCC’,

Corrosion Science, vol. 52, iss. 7, pp. 2511–2518.

Khizhnyakov, VI 2009, ‘Prevention of hydrogen

evolution when choosing the cathodic protection potential of

underground steel pipelines’, Corrosion: materials,

protection, no 9, pp. 7–10.

Liu, ZY, Li, NG & Cheng, YF 2012, ‘Mechanistic

aspect of near-neutral pH stress corrosion cracking of

pipelines under cathodic polarization’, Corrosion Science,

vol. 55, iss. 2, pp. 54–60.

Spiridovich, EA 2014, Improving the reliability of

gas pipelines in conditions of stress corrosion cracking: the

Doctor of Technical Sciences thesis: 25.00.19: defended on

/25/2014. Nizhny Novgorod: Gazprom VNIIGAZ LLC,

p. (in Russian)

Downloads

Published

2021-02-24

How to Cite

Nyrkova, L. I. . (2021). The influence of external and internal factors on stress corrosion cracking of low-alloyed pipe steel. JOURNAL OF HYDROCARBON POWER ENGINEERING, 7(1), 8–15. https://doi.org/10.31471/2311-1399-2020-1(13)-8-15