Fracture Surface Investigations of Api Pipes Welded With Parameters Determined By Taguchi Method

Year 2018, Volume: 22 Issue: 5, 1392 - 1402, 01.10.2018

Elif Aşıkuzun , Cemil Çetinkaya , Mustafa Boz , Hakan Ada

https://doi.org/10.16984/saufenbilder.397639

Cited By: 1

Abstract

In this study,
SEM images of the samples taken from welded nick break tests of API 5L X65 pipe
joints, whose welding parameters were determined by Taguchi method, were
examined. As a result of the investigations, the elongations and orientations
exhibited by the grains showed that ductile and brittle fractures were observed
in the welded joints. As it was observed from equiaxed, honeycomb like images
that the fractures exhibited a ductile behavior. Brittle fractures that occurred
due to cleavage breaks in some regions were detected. An  apparent effect of welding direction was
observed in fracture behavior. It was detected from the SEM images that a
ductile fracture structure had occurred in all joints that were performed from
bottom to top, while it was observed in the joints performed from top to bottom
that generally cleavage planes had developed along with fibrous structures in
places, therefore brittle fractures had occurred.

Keywords

API 5L X65, Fracture surface, SEM

References

• Reference 1 Umbach, F., “Global energy security and the implications for the EU”, Energy Policy, 38: 1229 – 1240, (2010).Reference 2 Ada, H., Aksöz, S., Fındık, T., Çetinkaya, C., and Gülsün, M. (2016). Tozaltı kaynak yöntemiyle birleştirilen petrol ve doğalgaz borularının mikroyapı ve mekanik özelliklerinin incelenmesi. Politeknik Dergisi, 19 (3): 275-282. Reference 3 Ada, H., Aksöz S., Fındık T., Çetinkaya C., Bostan B., Candan İ., “API 5L X65 Çeliklerinin MAG Kaynak Yöntemi ile Birleştirilmesinde, Kaynak İşleminin Mikroyapı ve Mekanik Özelliklere Etkisinin İncelenmesi”, Çukurova University Journal of the Faculty of Engineering and Architecture, 31: (ÖS 1), 1- 9, (2016).Reference 4 API Specifications 5L, “Specifications for Line Pipe”. 45th Edition, American Petroleum Institute, USA, 2012.Reference 5 Hashemi, S.H., "Strength - hardness statistical correlation in API X65 steel", Mater. Sci. Eng. A, Cit 528: 1648–1655, 2011. Reference 6 Rakhshkhorshid, M., Hashemi, S.H., “Experimental study of hot deformation behavior in API X65 steel”, Materials Science & Engineering A, Cilt 573 :37–44, 2013.Reference 7 Hashemi, S.H., Mohammadyani, D., “Characterization of weldment hardness, impact energy and microstructure in API X65 steel”, Int. J. Pressure Vessels Piping, Cilt 98: 8–15, 2012. Reference 8 Radovic, A., Bajic, N., and Grabulov, V., “Specific quality of the weld metal of welded joints of finegrained microalloyed steels”, Zavarivanje 96, 61–72, Belgrade, 1996.Reference 9 Bajic, N., Sijacki-Zeravcic, V., Rakin, M., and Kovacevic, K., “Structure optimization of weld metal and HAZ in microalloyed high strength steel welded joints”, Yucomat 2005, Herceg Novi, (ISBN: 86- 80321-08-7), pp. 193–200, 2005. Reference 10 Bajic and, N.V. Šijaki-Žeravi, “The analysis of change of structural and mechanical properties of welded joints of microalloyed Nb/V steel grade by changing the composition of filler material”, Internat. Conf. On Welding, Belgrade, 2003. Reference 11 Rani, Amitha, B.E. and Basu, Bharathibai, J., “Green corrosion inhibitors - an overview”, Technical Report, National Aerospace Laboratories, Bangalore, India, 2009.Reference 12 Migahed, M.A., Al-Sabagh, A.M., Khamis, E.A., Zaki, E.G., “Quantum Chemical calculations, synthesis and corrosion inhibition efficiency of ethoxylated- [2- (2 - {2 - [2- (2 –benzen esulfonylaminoethylamino) - ethylamino] - ethylamino} - ethylamino) - ethyl] -4 - alkyl benzenesulfonamide on API X65 steel surface under H2S environment”, Journal of Molecular Liquids, 212: 360–371, 2015. Reference 13 http://w3.balikesir.edu.tr/~ay/lectures/km/lecture1.pdfReference 14 Hagedorn, K. E., Kaspar, R., and Kleine, R. (1990). Untersuchungen zum einfluss des gefügesauf bruchmechanische kennwerte. Steel Research, 61(10): 510-517.Reference 15 Taş, Z. (2004). Termomekanik İşlem Görmüş Mikroalaşımlı Çeliklerin Kırılma Mekaniği -Kırılma Tokluğu- Açısından İncelenmesi, Doktora Tezi, YTÜ Fen Bilimleri Enstitüsü, İstanbul, 107.