Journal of Materials Engineering and Performance

, Volume 25, Issue 11, pp 4933–4940 | Cite as

Effect of Microstructural Parameters on Fatigue Crack Propagation in an API X65 Pipeline Steel

  • M. A. Mohtadi-BonabEmail author
  • M. Eskandari
  • H. Ghaednia
  • S. Das

In the current research, we investigate fatigue crack growth in an API X65 pipeline steel by using an Instron fatigue testing machine. To this, first the microstructure of steel was accurately investigated using scanning electron microscope. Since nonmetallic inclusions play a key role during crack propagation, the type and distribution of such inclusions were studied through the thickness of as-received X65 steel using energy-dispersive spectroscopy technique. It was found that the accumulation of such defects at the center of thickness of the pipe body was higher than in other regions. Our results showed that there were very fine oxide inclusions (1-2 µm in length) appeared throughout the cross section of X65 steel. Such inclusions were observed not at the fatigue crack path nor on both sides of the fatigue crack. However, we found that large manganese sulfide inclusions (around 20 µm in length) were associated with fatigue crack propagation. Fatigue experiments on CT specimens showed that the crack nucleated when the number of fatigue cycles was higher than 340 × 103. On fracture surfaces, crack propagation also occurred by joining the microcracks at tip of the main crack.


back-scattered electron energy-dispersive spectroscopy fatigue crack pipeline steel scanning electron microscopy 



We would like to thank Natural Sciences and Engineering Research Council of Canada for the financial support of this project. We also sincerely thank for the support received from Centre for Engineering Research in Pipelines (CERP) located in Windsor, ON, Canada.


  1. 1.
    E. Gamboa, V. Linton, and M. Law, Fatigue of Stress Corrosion Cracks in X65 Pipeline Steels, Int. J. Fatigue, 2008, 30, p 850–860CrossRefGoogle Scholar
  2. 2.
    R.L. Amaro, N. Rustagi, K.O. Findley, E.S. Drexler, and A.J. Slifka, Modeling the Fatigue Crack Growth of X100 Pipeline Steel in Gaseous Hydrogen, Int. J. Fatigue, 2014, 59, p 262–271CrossRefGoogle Scholar
  3. 3.
    M.A. Arafin and J.A. Szpunar, Effect of Bainitic Microstructure on the Susceptibility of Pipeline Steels to Hydrogen Induced Cracking, Mater. Sci. Eng., A, 2011, 528, p 4927–4940CrossRefGoogle Scholar
  4. 4.
    M.A. Arafin and J.A. Szpunar, A New Understanding of Intergranular Stress Corrosion Cracking Resistance of Pipeline Steel Through Grain Boundary Character and Crystallographic Texture Studies, Corros. Sci., 2009, 51, p 119–128CrossRefGoogle Scholar
  5. 5.
    M.A. Mohtadi-Bonab, R. Karimdadashi, M. Eskandari, and J.A. Szpunar, Hydrogen-Induced Cracking Assessment in Pipeline Steels Through Permeation and Crystallographic Texture Measurements, J. Mater. Eng. Perform., 2016, 25, p 1781–1793CrossRefGoogle Scholar
  6. 6.
    V.M. Pleskach and P.A. Averchenko, Effect of Gaseous Erosion on a Decrease of the Fatigue Strength of Specimens of Titanium Alloy VT8, Strength Mater., 1975, 7, p 1036–1037CrossRefGoogle Scholar
  7. 7.
    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, Int. J. Hydrogen Energy, 2012, 37, p 11474–11486CrossRefGoogle Scholar
  8. 8.
    H.J. Christ, A. Jung, H.J. Maier, and R. Teteruk, Thermomechanical Fatigue-Damage Mechanisms and Mechanism-Based Life Prediction Methods, Sadhana, 2003, 28, p 147–165CrossRefGoogle Scholar
  9. 9.
    S. Hassanifard, M.A. Mohtadi-Bonab, and Gh Jabbari, Investigation of Fatigue Crack Propagation in Spot-Welded Joints Based on Fracture Mechanics Approach, J. Mater. Eng. Perform., 2013, 22, p 245–250CrossRefGoogle Scholar
  10. 10.
    J.F. Cooper and R.A. Smith, The Measurement of Fatigue Cracks at Spot-Welds, Int. J. Fatigue, 1985, 7, p 137–140CrossRefGoogle Scholar
  11. 11.
    J.W. Sowards, T. Gnäupel-Herold, J.D. McColskey, V.F. Pereira, and A.J. Ramirez, Characterization of Mechanical Properties, Fatigue-Crack Propagation, and Residual Stresses in a Microalloyed Pipeline-Steel Friction-Stir Weld, Mater. Des., 2015, 88, p 632–642Google Scholar
  12. 12.
    J.A. Ronevich, B.P. Somerday, and C.W.S. Marchi, Effects of Microstructure Banding on Hydrogen Assisted Fatigue Crack Growth in X65 Pipeline Steels, Int. J. Fatigue, 2016, 82, p 497–504CrossRefGoogle Scholar
  13. 13.
    M. Yu, W. Chen, R. Kania, G. Boven, and J. Been, Crack Propagation of Pipeline Steel Exposed to a Near-Neutral pH Environment Under Variable Pressure Fluctuations, Int. J. Fatigue, 2016, 82, p 658–666CrossRefGoogle Scholar
  14. 14.
    B.T. Lu, Further Study on Crack Growth Model of Buried Pipelines Exposed to Concentrated Carbonate-Bicarbonate Solution, Eng. Fract. Mech., 2014, 131, p 296–314CrossRefGoogle Scholar
  15. 15.
    F. Huang, J. Liu, Z.J. Deng, J.H. Cheng, Z.H. Lu, and X.G. Li, Effect of Microstructure and Inclusions on Hydrogen Induced Cracking Susceptibility and Hydrogen Trapping Efficiency of X120 pipeline steel, Mater. Sci. Eng., A, 2010, 527, p 6997–7001CrossRefGoogle Scholar
  16. 16.
    J. Moon, C. Park, and S.J. Kim, Influence of Ti Addition on the Hydrogen Induced Cracking of API, 5L X70 Hot-Rolled Pipeline Steel in Acid Sour Media, Met. Mater. Int., 2012, 18, p 613–617CrossRefGoogle Scholar
  17. 17.
    G.T. Park, S.U. Koh, H.G. Jung, and K.Y. Kim, Effect of Microstructure on the Hydrogen Trapping Efficiency and Hydrogen Induced Cracking of Linepipe Steel, Corros. Sci., 2008, 50, p 1865–1871CrossRefGoogle Scholar
  18. 18.
    M.L. Hayne, P.I. Anderson, K.O. Findley, and C.J. Van Tyne, Effect of Microstructural Banding on the Fatigue Behavior of Induction-Hardened 4140 steel, Metall. Mater. Trans. A, 2013, 44, p 3428–3433CrossRefGoogle Scholar
  19. 19.
    N. Cyril, A. Fatemi, and B. Cryderman, Effects of Sulfur Level and Anisotropy of Sulfide Inclusions on Tensile, Impact, and Fatigue Properties of SAE 4140 Steel, SAE Int. J. Mater. Manuf., 2009, 1, p 218–827CrossRefGoogle Scholar
  20. 20.
    Y. Yang, L. Shi, Z. Xu, H. Lu, X. Chen, and X. Wang, Fracture Toughness of the Materials in Welded Joint of X80 Pipeline Steel, Eng. Fract. Mech., 2015, 148, p 337–349CrossRefGoogle Scholar
  21. 21.
    C. Ruggieri and E. Hippert, Delamination Effects on Fracture Behavior of a Pipeline Steel: A Numerical Investigation of 3-D Crack Front Fields and Constraint, Int. J. Pres. Vess. Pip., 2015, 128, p 18–35CrossRefGoogle Scholar
  22. 22.
    M.A. Mohtadi-Bonab, J.A. Szpunar, L. Collins, and R. Stankiewich, Evaluation of Hydrogen Induced Cracking Behavior of API, X70 Pipeline Steel at Different Heat Treatments, Int. J. Hydrogen Energy, 2014, 39, p 6076–6088CrossRefGoogle Scholar
  23. 23.
    M.A. Mohtadi-Bonab, J.A. Szpunar, and S.S. Razavi-tousi, Hydrogen Induced Cracking Susceptibility in Different Layers of a Hot Rolled X70 Pipeline Steel, Int. J. Hydrogen Energy, 2013, 38, p 13831–13841CrossRefGoogle Scholar
  24. 24.
    M.A. Mohtadi-Bonab, M. Eskandari, and J.A. Szpunar, Texture, Local Misorientation, Grain Boundary and Recrystallization Fraction in Pipeline Steels Related to Hydrogen Induced Cracking, Mater. Sci. Eng., A, 2015, 620, p 97–106CrossRefGoogle Scholar
  25. 25.
    M.A. Mohtadi-Bonab, J.A. Szpunar, R. Basu, and M. Eskandari, The Mechanism of Failure by Hydrogen Induced Cracking in an Acidic Environment for API, 5L X70 Pipeline Steel, Int. J. Hydrogen Energy, 2015, 40, p 1096–1107CrossRefGoogle Scholar
  26. 26.
    M.A. Mohtadi-Bonab, M. Eskandari, K.M.M. Rahman, R. Ouellet, M. Eskandari, and J.A. Szpunar, An Extensive Study of Hydrogen-Induced Cracking Susceptibility in an API, X60 Sour Service Pipeline Steel, Int. J. Hydrogen Energy, 2016, 41, p 4185–4197CrossRefGoogle Scholar
  27. 27.
    M.A. Mohtadi-Bonab, J.A. Szpunar, and S.S. Razavi-tousi, A Comparative Study of Hydrogen Induced Cracking Behavior in API, 5L X60 and X70 Pipeline Steels, Eng. Fail. Anal., 2016, 33, p 163–175CrossRefGoogle Scholar

Copyright information

© ASM International 2016

Authors and Affiliations

  • M. A. Mohtadi-Bonab
    • 1
    Email author
  • M. Eskandari
    • 2
  • H. Ghaednia
    • 3
  • S. Das
    • 3
  1. 1.Department of Mechanical Engineering, Faculty of EngineeringUniversity of BonabBonabIran
  2. 2.Department of Materials Science and Engineering, Faculty of EngineeringShahid Chamran University of AhvazAhvazIran
  3. 3.Centre for Engineering Research in Pipelines (CERP)University of WindsorWindsorCanada

Personalised recommendations