Abstract
The weld defects were detected by Nondestructive Testing Technology(NTT). The microstructure and microhardness were examined by optical microscope(OM), scanning electron microscopy (SEM) equipped with EDS and Vicker microhardness tester to identify the reasons of cracking failure in X70 pipeline steel weldment. As a result, the microstructure in the root layer and filling layer of the weld presents ferrite and pearlite while it is ferrite and bainite in the covering layer, but the morphology and distribution as well as the content of ferrite and pearlite in the root layer are different from which in the filling layer; the cracks initiate at the root of the weld and propagate towards filling layer, and the C, O, S segregation is serious, which contribute to the initiation and propagation of the crack in the weld; the hardness decreases sharply around the crack tip, which exhibits lower strength.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
E.S. Meresht, T.S. Farahani, J. Neshati, Failure analysis of stress corrosion cracking occurred in a gas transmission steel pipeline. J. Eng. Fail. Anal. 18, 963–970 (2011)
M.A. Mohtadi-Bonab, J.A. Szpunar, R. Basu et al., The mechanism of failure by hydrogen induced cracking in an acidic environment for API 5L X70 pipeline steel. J. international journal of hydrogen energy. 40, 1096–1107 (2015)
C.R.F. Azevedo, Failure analysis of a crude oil pipeline. J. Eng. Fail. Anal. 14, 978–994 (2007)
A.Q. Fu, X.R. Kuang, Y. Han et al., Failure analysis of girth weld cracking of mechanically lined pipe used in gasfield gathering system. J. Eng. Fail. Anal. 68, 64–75 (2016)
A. Farzadi, Gas pipeline failure caused by in-service welding. J. Pressure Vessel Technol. 138, 011405 (2016)
H. Alipooramirabad, A. Paradowska, R. Ghomashchi et al., Investigating the effects of welding process on residual stresses, microstructure and mechanical properties in HSLA steel welds. J. Manuf. Process. 28, 70–81 (2017)
F. Shen, B. Zhao, L. Li et al., Fatigue damage evolution and lifetime prediction of welded joints with the consideration of residual stresses and porosity. Int. J. Fatigue. 163, 272–279 (2017)
T. Łagoda, P. Biłous, Ł. Blacha, Investigation on the effect of geometric and structural notch on the fatigue notch factor in steel welded joints. Int. J. Fatigue 101, 224–231 (2017)
Wang A, Shi Y, Chen C, Effect of aging-deformation-treatment on the formation of intragranular ferrite in V-microalloyed steel. J. Mater. Sci. Technol. 1–6 (2017)
Natividad C, García R, López VH et al. Metallurgical characterization of API X65 steel joint welded by MIG welding process with axial magnetic field. J. Mater. Res. 8–17 (2017)
R. Jiang, S. Everitt, N. Gao et al., Influence of oxidation on fatigue crack initiation and propagation in turbine disc alloy N18. J. Int. Fatigue. 75, 89–99 (2015)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2018 Springer Nature Singapore Pte Ltd.
About this paper
Cite this paper
Wang, B., Zhang, S., Zhou, C., Liu, N., Wang, L., Tian, X. (2018). Cracking Failure Analysis of X70 Pipeline Steel Weld. In: Han, Y. (eds) Advances in Energy and Environmental Materials. CMC 2017. Springer Proceedings in Energy. Springer, Singapore. https://doi.org/10.1007/978-981-13-0158-2_40
Download citation
DOI: https://doi.org/10.1007/978-981-13-0158-2_40
Published:
Publisher Name: Springer, Singapore
Print ISBN: 978-981-13-0157-5
Online ISBN: 978-981-13-0158-2
eBook Packages: EnergyEnergy (R0)