Journal of Materials Engineering and Performance

, Volume 27, Issue 4, pp 1694–1705 | Cite as

Effect of Different Thermomechanical Processes on the Microstructure, Texture, and Mechanical Properties of API 5L X70 Steel

  • Mohammad Masoumi
  • Edwan Anderson Ariza Echeverri
  • Cleiton Carvalho Silva
  • Miloslav Béreš
  • Hamilton Ferreira Gomes de Abreu


A commercial API 5L X70 steel plate was subjected to different thermomechanical processes to propose a novel thermomechanical rolling path to achieve improved mechanical properties. Scanning electron microscopy, electron backscatter diffraction, and x-ray texture analysis were employed for microstructural characterization. The results showed that strain-free recrystallized {001} ferrite grains that developed at higher rolling temperature could not meet the American Petroleum Institute (API) requirements. Also, refined and work-hardened grains that have formed in the intercritical region with high stored energy do not provide suitable tensile properties. However, fine martensite–austenite constituents dispersed in ferrite matrix with grains having predominantly {111} and {110} orientations parallel to the normal direction that developed under isothermal rolling at 850 °C provided an outstanding combination of tensile strength and ductility.


API 5L X70 steel crystallographic texture thermomechanical processes 



The authors acknowledge the CAPES and CNPq Brazilian research agencies for financial support and Central Analítica-UFC/CT-INFRA/MCTI-SISNANO/Pró-Equipamentos for providing research facilities used in this work.


  1. 1.
    K. Banerjee, Hydrogen-Induced Cold Cracking in High-Frequency Induction Welded Steel Tubes, Metall. Mater. Trans. A, 2016, 47(4), p 1677–1685CrossRefGoogle Scholar
  2. 2.
    X. Liang and A.J. Deardo, A Study of the Influence of Thermomechanical Controlled Processing on the Microstructure of Bainite in High Strength Plate Steel, Metall. Mater. Trans. A, 2014, 45(11), p 5173–5184CrossRefGoogle Scholar
  3. 3.
    S.Y. Shin, B. Hwang, S. Lee, N.J. Kim, and S.S. Ahn, Correlation of Microstructure and Charpy Impact Properties in API, X70 and X80 Line-Pipe Steels, Mater. Sci. Eng. A, 2007, 458(1–2), p 281–289CrossRefGoogle Scholar
  4. 4.
    S. Nafisi, M.A. Arafin, L. Collins, and J. Szpunar, Texture and Mechanical Properties of API, X100 Steel Manufactured Under Various Thermomechanical Cycles, Mater. Sci. Eng. A, 2012, 531, p 2–11CrossRefGoogle Scholar
  5. 5.
    H.K. Sung et al., Correlation Between Microstructures and Tensile Properties of Strain-Based API, X60 Pipeline Steels, Metall. Mater. Trans. A, 2016, 47(6), p 2726–2738CrossRefGoogle Scholar
  6. 6.
    H.K. Sung et al., Effects of Finish Cooling Temperature on Tensile Properties After Thermal Aging of Strain-Based API, X60 Linepipe Steels, Metall. Mater. Trans. A, 2015, 46(9), p 3989–3998CrossRefGoogle Scholar
  7. 7.
    K. Huang and R.E. Logé, A Review of Dynamic Recrystallization Phenomena in Metallic Materials, Mater. Des., 2016, 111, p 548–574CrossRefGoogle Scholar
  8. 8.
    M. Masoumi, C.C. Silva, H. Ferreira, and G. De Abreu, Effect of Rolling in the Recrystallization Temperature Region Associated with a Post-Heat Treatment on the Microstructure, Crystal Orientation, and Mechanical Properties of API, 5L X70 Pipeline Steel, Mater. Res., 2017, 20(1), p 151–160CrossRefGoogle Scholar
  9. 9.
    A. Gourgues, H.M. Flower, and T.C. Lindley, Electron Backscattering Diffraction Study of Acicular Ferrite, Bainite, and Martensite Steel Microstructures, Mater. Sci. Technol., 2000, 16, p 26–40CrossRefGoogle Scholar
  10. 10.
    V.R.D.J. Dingley and K.Z. Baba-Kishi, Atlas of Backscattering Kikuchi Diffraction Patterns, Microscopy in Materials Science Series Institute of Physics Publishing, Philadelphia, 1995, p 299–306Google Scholar
  11. 11.
    G. Sainath and B.K. Choudhary, Orientation Dependent Deformation Behaviour of BCC Iron Nanowires, Comput. Mater. Sci., 2016, 111, p 406–415CrossRefGoogle Scholar
  12. 12.
    C. Herrera, N.B. Lima, A.F. Filho, R.L. Plaut, and A.F. Padilha, Texture and Mechanical Properties Evolution of a Deep Drawing Medium Carbon Steel During Cold Rolling and Subsequent Recrystallization, J. Mater. Process. Technol., 2009, 209, p 3518–3524CrossRefGoogle Scholar
  13. 13.
    A. Ghosh, S. Kundu, and D. Chakrabarti, Effect of Crystallographic Texture on the Cleavage Fracture Mechanism and Effective Grain Size of Ferritic Steel, Scr. Mater., 2014, 81, p 8–11CrossRefGoogle Scholar
  14. 14.
    V. Venegas, F. Caleyo, J.M. Hallen, T. Baudin, and R. Penelle, Role of Crystallographic Texture in Hydrogen-Induced Cracking of Low Carbon Steels for Sour Service Piping, Metall. Mater. Trans. A, 2007, 38, p 1022–1031CrossRefGoogle Scholar
  15. 15.
    V. Venegas, F. Caleyo, T. Baudin, J.H. Espina-Hernández, and J.M. Hallen, On the Role of Crystallographic Texture in Mitigating Hydrogen-Induced Cracking in Pipeline Steels, Corros. Sci., 2011, 53, p 4204–4212CrossRefGoogle Scholar
  16. 16.
    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
  17. 17.
    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
  18. 18.
    B. Mirzakhani, M.T. Salehi, S. Khoddam, S.H. Seyedein, and M.R. Aboutalebi, Investigation of Dynamic and Static Recrystallization Behavior During Thermomechanical Processing in a API-X70 Microalloyed Steel, J. Mater. Eng. Perform., 2009, 18, p 1029–1034CrossRefGoogle Scholar
  19. 19.
    S.Y. Shin, K.J. Woo, B. Hwang, S. Kim, and S. Lee, Fracture-Toughness Analysis in Transition-Temperature Region of Three American Petroleum Institute X70 and X80 Pipeline Steels, Metall. Mater. Trans. A, 2009, 40, p 867–876CrossRefGoogle Scholar
  20. 20.
    E. El-Danaf, M. Baig, A. Almajid, W. Alshalfan, M. Al-Mojil, and S. Al-Shahrani, Mechanical, Microstructure and Texture Characterization of API, X65 Steel, Mater. Des., 2013, 47, p 529–538CrossRefGoogle Scholar
  21. 21.
    A. 562-02, Standard Test Method for Determining Volume Fraction by Systematic Manual Point Count (ASTM, 2002)Google Scholar
  22. 22.
    F. Bachmann, R. Hielscher, and H. Schaeben, Ultramicroscopy Grain Detection from 2d and 3d EBSD Data—Specification of the MTEX Algorithm, Ultramicroscopy, 2011, 111, p 1720–1733CrossRefGoogle Scholar
  23. 23.
    D.A. Hughes, High Angle Boundaries Formed by Grain Subdivision Mechanisms, Acta Mater., 1997, 45, p 3871–3886CrossRefGoogle Scholar
  24. 24.
    J.H. Yang, Q.Y. Liu, D.B. Sun, and X.Y. Li, Microstructure and Transformation Characteristics of Acicular Ferrite in High Niobium-Bearing Microalloyed Steel, J. Iron Steel Res. Int., 2010, 17(6), p 53–59CrossRefGoogle Scholar
  25. 25.
    R.D.A. Silva, L.F.G. Souza, E.V. Morales, P.R. Rios, and I.D.S. Bott, Formation of Microphases and Constituents from Remaining Austenite Decomposition in API, X80 Steel Under Different Processing Conditions, Mater. Res., 2015, 18(5), p 908–917CrossRefGoogle Scholar
  26. 26.
    E. Tsl and E. South, Phase Differentiation via Combined EBSD and XEDS, J. Microsc., 2004, 213, p 296–305CrossRefGoogle Scholar
  27. 27.
    S.J.S. Qazi, A.R. Rennie, J.K. Cockcroft, and M. Vickers, Use of Wide-Angle X-ray Diffraction to Measure Shape and Size of Dispersed Colloidal Particles, J. Colloid Interface Sci., 2009, 338, p 105–110CrossRefGoogle Scholar
  28. 28.
    P. Cizek, B.P. Wynne, C.H.J. Davies, B.C. Muddle, and P.D. Hodgson, Effect of Composition and Austenite Deformation on the Transformation Characteristics of Low-Carbon and Ultralow-Carbon Microalloyed Steels, Metall. Mater. Trans. A, 2002, 33, p 1331–1349CrossRefGoogle Scholar
  29. 29.
    J.B. Seol, D. Raabe, P.P. Choi, Y.R. Im, and C.G. Park, Atomic Scale Effects of Alloying, Partitioning, Solute Drag and Austempering on the Mechanical Properties of High-Carbon Bainitic-Austenitic TRIP Steels, Acta Mater., 2012, 60(17), p 6183–6199CrossRefGoogle Scholar
  30. 30.
    G. Thomas, J. Speer, D. Matlock, and J. Michael, Application of Electron Backscatter Diffraction Techniques to Quenched and Partitioned Steels, Microsc. Microanal., 2011, 17(3), p 368–373CrossRefGoogle Scholar
  31. 31.
    F.J. Humphreys, and M. Hatherly, The deformed state, in Recrystallization and Related Annealing Phenomena, 2 edn. (Elsevier, Oxford, 2004), pp. 11–65.Google Scholar
  32. 32.
    R. Blonde et al., High-Resolution X-ray Diffraction Investigation on the Evolution of the Substructure of Individual Austenite Grains in TRIP Steels During Tensile Deformation, Mater. Sci. Eng. A, 2014, 47(3), p 965–973Google Scholar
  33. 33.
    P.J. Konijnenberg, S. Zaefferer, and D. Raabe, Acta Materialia Assessment of Geometrically Necessary Dislocation Levels Derived by 3D EBSD, Acta Mater., 2015, 99, p 402–414CrossRefGoogle Scholar
  34. 34.
    S.I. Wright, M.M. Nowell, S.P. Lindeman, P.P. Camus, M. De Graef, and M.A. Jackson, Ultramicroscopy Introduction and Comparison of New EBSD Post-Processing Methodologies, Ultramicrosc. J., 2015, 159, p 81–94CrossRefGoogle Scholar
  35. 35.
    V.A. Borodin, P.V. Vladimirov, and A. Möslang, The Effects of Temperature on (001)〈110〉 crack propagation in bcc iron, J. Nucl. Mater., 2013, 442(1), p 612–617CrossRefGoogle Scholar
  36. 36.
    M. Eskandari, A. Zarei-Hanzaki, J.A. Szpunar, M.A. Mohtadi-Bonab, A.R. Kamali, and M. Nazarian-Samani, Microstructure Evolution and Mechanical Behavior of a New Microalloyed High Mn Austenitic Steel During Compressive Deformation, Mater. Sci. Eng. A, 2014, 615, p 424–435CrossRefGoogle Scholar
  37. 37.
    M. Eskandari, M.A. Mohtadi-Bonab, and J.A. Szpunar, Evolution of the Microstructure and Texture of X70 Pipeline Steel During Cold-Rolling and Annealing Treatments, Mater. Des., 2016, 90, p 618–627CrossRefGoogle Scholar
  38. 38.
    M.J. Serenelli, M.A. Bertinetti, and J.W. Signorelli, Investigation of the Dislocation Slip Assumption on Formability of BCC Sheet Metals, Int. J. Mech. Sci., 2010, 52, p 1723–1734CrossRefGoogle Scholar
  39. 39.
    L. Dezerald, D. Rodney, E. Clouet, L. Ventelon, and F. Willaime, Plastic Anisotropy and Dislocation Trajectory in BCC Metals, Nat. Commun., 2016, 7, p 11695CrossRefGoogle Scholar
  40. 40.
    J. Wang, A. Misra, R.G. Hoagland, and J.P. Hirth, Slip Transmission Across FCC/BCC Interfaces with Varying Interface Shear Strengths, Acta Mater., 2012, 60, p 1503–1513CrossRefGoogle Scholar
  41. 41.
    API 5L, Specification for Line Pipe, vol. 42 (American Petroleum Institute, 2000), p. 153Google Scholar
  42. 42.
    W.-S. Lee and T.-T. Su, Mechanical Properties and Microstructural Features of AISI, 4340 High-Strength Alloy Steel Under Quenched and Tempered Conditions, J. Mater. Process. Technol., 1999, 87(1–3), p 198–206CrossRefGoogle Scholar
  43. 43.
    M.Y. Tu, C.A. Hsu, W.H. Wang, and Y.F. Hsu, Comparison of Microstructure and Mechanical Behavior of Lower Bainite and Tempered Martensite in JIS SK5 Steel, Mater. Chem. Phys., 2008, 107(2–3), p 418–425CrossRefGoogle Scholar

Copyright information

© ASM International 2018

Authors and Affiliations

  • Mohammad Masoumi
    • 1
    • 2
  • Edwan Anderson Ariza Echeverri
    • 1
  • Cleiton Carvalho Silva
    • 2
  • Miloslav Béreš
    • 2
  • Hamilton Ferreira Gomes de Abreu
    • 2
  1. 1.Department of Metallurgical and Materials EngineeringUniversity of São PauloSão PauloBrazil
  2. 2.Department of Metallurgical and Materials EngineeringFederal University of CearáFortalezaBrazil

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