Volume 19, Issue 7 (July 2019)                   Modares Mechanical Engineering 2019, 19(7): 1591-1600 | Back to browse issues page

XML Persian Abstract Print

Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:

Hashemi H, Hashemi S. Investigation of Macroscopic Fracture Surface Characteristics of API X65 Steel Using Three-point Bending Test. Modares Mechanical Engineering 2019; 19 (7) :1591-1600
URL: http://mme.modares.ac.ir/article-15-21024-en.html
1- Mechanical Engineering Department, Engineering Faculty, University of Birjand, Birjand, Iran
2- Research Center on Pipeline & Related Industries, University of Birjand, Birjand, Iran , shhashemi@birjand.ac.ir
Abstract:   (7467 Views)
The API X65 steel (with a minimum yield strength of 65ksi equivalent to 448MPa) is one of the most common types of pipe steels in the transportation of natural gas in Iran. By studying the ductile and brittle fracture areas at the fracture surface of this steel, we can show the quality of this type of steel. In the present study, macroscopic fracture surface characteristics in three-point bending test specimen are studied (based on the geometry and standard notch of drop-weight tear test specimen). Test specimens were machined from an actual steel pipe of API X65 grade with an external diameter of 1219 mm (48 inches) and wall thickness of 14.3 mm. Due to the quasi-static test conditions and speed of the machine's jaw (0.1 mm/s), the test was carried out on base metal specimens with machine chevron notch of 15, 10, and 5.1 mm depth, respectively, that was controlled with changing location. By applying the test load, cracking initiated from the notch root in each specimen and continued without crack specimen (ligament). At the end of the test, test specimens were cooled by liquid nitrogen and were broken in a brittle manner. In this paper, after investigation of the failure mode and the crack expansion in the standard specimen, investigation of macroscopic fracture surface characteristics was conducted by optical microscopy. By observing the fracture surface, different features such as thickness variation, shear regions (ductile fracture), cleavage fracture, shear lips, inverse fracture, and brittle fracture were studied. Having above 85% shear area, the ductile fracture of specimen was confirmed.
Full-Text [PDF 1106 kb]   (2988 Downloads)    
Article Type: Original Research | Subject: Damage Mechanics
Received: 2018/05/19 | Accepted: 2019/03/19 | Published: 2019/07/2

1. Forouzanfar M, Doustmohammadi A, Menhaj MB, Hasanzadeh S. Modeling and estimation of the natural gas consumption for residential and commercial sectors in Iran. Applied Energy. 2010;87(1):268-274. [Link] [DOI:10.1016/j.apenergy.2009.07.008]
2. Economides MJ, Wood DA. The state of natural gas. Journal of Natural Gas Science and Engineering. 2009;1(1-2):1-13. [Link] [DOI:10.1016/j.jngse.2009.03.005]
3. Hashemi SH. Strength-hardness statistical correlation in API X65 steel. Materials Science and Engineering A. 2011;528(3):1648-1655. [Link] [DOI:10.1016/j.msea.2010.10.089]
4. El-Danaf E, Baig M, Almajid A, Alshalfan W, Al-Mojil M, Al-Shahrani S. Mechanical, microstructure and texture characterization of API X65 steel. Materials & Design. 2013;47:529-538. [Link] [DOI:10.1016/j.matdes.2012.12.031]
5. Zhao MC, Yang K, Shan Y. The effects of thermo-mechanical control process on microstructures and mechanical properties of a commercial pipeline steel. Materials Science and Engineering A. 2002;335(1-2):14-20. [Link] [DOI:10.1016/S0921-5093(01)01904-9]
6. Van Tyne CJ. 1.01 - Introduction to Assessing Properties of Conventional and Specialized Materials. Comprehensive Materials Processing. 2014;1:1-2. [Link] [DOI:10.1016/B978-0-08-096532-1.00100-X]
7. Verlinden B, Driver J, Samajdar I, Doherty RD. Thermo-mechanical processing of metallic materials. 1st Editoin. London: Elsevier; 2007. pp. 425-429. [Link]
8. Zhu XK, Joyce JA. Review of fracture toughness (G, K, J, CTOD, CTOA) testing and standardization. Engineering Fracture Mechanics. 2012;85:1-46. [Link] [DOI:10.1016/j.engfracmech.2012.02.001]
9. Rudland DL, Wang YY, Wilkowski G, Horsley DJ. Characterizing dynamic fracture toughness of linepipe steels using the pressed-notch drop-weight-tear test specimen. Engineering Fracture Mechanics. 2004;71(16-17):2533-2549. [Link] [DOI:10.1016/S0013-7944(04)00015-3]
10. Fang J, Zhang J, Wang L. Evaluation of cracking behavior and critical CTOA values of pipeline steel from DWTT specimens. Engineering Fracture Mechanics. 2014;124-125:18-29. [Link] [DOI:10.1016/j.engfracmech.2014.04.031]
11. Majidi Jirandehi AA, Hashemi SH. Investigation of macroscopic fracture surface characteristics of spiral welded API X65 gas transportation pipeline steel. Modares Mechanical Engineering. 2018;17(11):219-228. [Persian] [Link]
12. Hari Manoj Simha C, Xu S, Tyson WR. Non-local phenomenological damage-mechanics-based modeling of the drop-weight tear test. Engineering Fracture Mechanics. 2014;118:62-82. [Link] [DOI:10.1016/j.engfracmech.2014.01.009]
13. Callister WD, Rethwisch DG. Materials science and engineering an introduction. 9th Edition. New York: Wiley; 2014. pp. 251-258. [Link]
14. Hwang B, Lee S, Kim YM, Kim NJ, Yoo JY, Woo CS. Analysis of abnormal fracture occurring during drop-weight tear test of high-toughness line-pipe steel. Materials Science and Engineering A. 2004;368(1-2):18-27. [Link] [DOI:10.1016/j.msea.2003.09.075]
15. Yang Z. The fracture during drop-weight tear test of high performance pipeline steel and its abnormal fracture appearance. Procedia Materials Science. 2014;3:1591-1598. [Link] [DOI:10.1016/j.mspro.2014.06.257]
16. Yang Z, Kim CB, Feng Y, Cho C. Abnormal fracture appearance in drop-weight tear test specimens of pipeline steel. Materials Science and Engineering A. 2008;483-484:239-241. [Link] [DOI:10.1016/j.msea.2006.09.182]
17. Sung HK, Sohn SS, Shin SY, Lee S, Kim NJ, Chon SH, et al. Effects of finish rolling temperature on inverse fracture occurring during drop weight tear test of API X80 pipeline steels. Materials Science and Engineering A. 2012;541:181-189. [Link] [DOI:10.1016/j.msea.2012.02.019]
18. Amano T, Fujishiro T, Shinohara Y, Inoue T. Evaluation of pre-strain effect on abnormal fracture occurrence in drop-weight tear test for linepipe steel with high charpy energy. Procedia Structural Integrity.2016;2:422-429. [Link]
19. Shin SY, Hwang B, Lee S, Kang KB. Effects of notch shape and specimen thickness on drop-weight tear test properties of API X70 and X80 line-pipe steels. Metallurgical and Materials Transactions A. 2007;38(3):537-551. [Link] [DOI:10.1007/s11661-006-9073-6]
20. Hashemi SH, Mohammadyani D. Characterisation of weldment hardness, impact energy and microstructure in API X65 steel. International Journal of Pressure Vessels and Piping. 2012;98:8-15. [Link] [DOI:10.1016/j.ijpvp.2012.05.011]
21. American Petroleum Institute. API RP 5L3: Recommended practice for conducting drop-weight tear tests on line pipe, fourth edition [Internet]. Washington: API; 2014 [cited 2018 Dec 01]. Available from: https://www.techstreet.com/standards/api-rp-5l3?product_id=1881831 [Link]
22. American Petroleum Institute. API Specification 5L/ISO 3183 (Modified), specification for line pipe, 44th edition [Internet]. Washington: API; 2007 [cited 2018 Dec 01]. Available from: http://www.shunitesteel.com/wp-content/uploads/2013/05/API-5L-2007-Specification-for-Line-Pipe.pdf [Link]
23. Hertzberg RW, Vinci RP, Hertzberg JL. Deformation and fracture mechanics of engineering materials. 5th Edition. New York: Wiley; 2012. pp. 336-353. [Link]
24. Yamada Y, Lacy T, Newman Jr J, Smith BL, Kumar B. Effects of crack closure on fatigue crack-growth predictions for 2024-T351 aluminum alloy panels under spectrum loading. International Journal of Fatigue. 2007;29(8):1503-1509. [Link] [DOI:10.1016/j.ijfatigue.2006.10.026]
25. El-Naaman SA, Nielsen KL. Observations on mode I ductile tearing in sheet metals. European Journal of Mechanics A Solids. 2013;42:54-62. [Link] [DOI:10.1016/j.euromechsol.2013.04.007]
26. Xu S, Tyson WR, Eagleson R, Mc Cowan CN, Drexler ES, Mc Colskey JD, et al. Measurement of CTOA of pipe steels using MDCB and DWTT specimens. ASME Proceedings Materials and Joining 8th International Pipeline Conference. 2010;2:IPC2010-31076. [Link] [DOI:10.1115/IPC2010-31076]

Add your comments about this article : Your username or Email:

Send email to the article author

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.