Investigation on Weldability and Post-Weld Heat Treatment of A 333 Gr.6 and A350LF-2 Steels

Öz

In this study, as the first welding process, GTAW (Gas Tungsten Arc Welding) welding process was carried out on 9.53 mm thick A 333 Gr.6 pipe and A350LF-2 flange steels using 2.4 mm ER70S-6 electrode and SMAW (Manual Arc Welding) welding process was carried out using 2.5 mm E 7018-1 electrode for filler and cover passes. As the second welding process, GTAW welding process was carried out on 5.49 mm thick A 333 Gr.6 pipe and A350LF-2 flange steels using 2.4 mm ER70S-6 electrode and SMAW welding process was carried out using 2.5 mm E 7018-1 electrode for filler and cover passes. Post-weld heat treatment was applied during the first welding process. No post-weld heat treatment was applied during the second welding process. The effect of heat treatment on some mechanical properties of the materials and the changes that occur after stress relief were investigated for the welds made with the same materials, the same electrodes, the same welding methods but with different thicknesses. Tensile test, bending test, hardness test, notch impact test was performed as mechanical tests of the welded parts, macro images were taken and comparisons were made. As a result, the effects on the weld quality were investigated and results indicate that welding processes were successfully carried out with given filler electrodes and steel pipes.

Anahtar Kelimeler

• A 333 Gr.6
• A350LF-2
• GTAW
• SMAW

A 333 Gr.6 ile A350LF-2 Çeliklerinin Kaynaklanabilirliğinin ve Kaynak Sonrası Isıl İşlemlerinin İncelenmesi

Öz

Bu çalışamada ilk kaynak işlemi olarak, 9.53 mm kalınlığında A 333 Gr.6 boru ile A350LF-2 flanş çeliklerinin GTAW (Gaz Tungsten Ark Kaynağı) kaynak işlemi 2,4 mm ER70S-6 elektrodu kullanılarak, SMAW (Manuel Ark Kaynağı) kaynak işlemi ise dolgu ve kapak pasoları için 2,5 mm E 7018-1 elektrodu kullanılarak gerçekleştirilmiştir. İkinci kaynak işlemi olarak, 5.49 mm kalınlığında A 333 Gr.6 boru ile A350LF-2 flanş çeliklerinin GTAW kaynak işlemi 2,4 mm ER70S-6 elektrodu kullanılarak, SMAW kaynak işlemi ise dolgu ve kapak pasoları için 2,5 mm E 7018-1 elektrodu kullanılarak gerçekleştirilmiştir. İlk kaynak işlemi gerçekleştirilirken kaynak sonrası ısıl işlem uygulanmıştır. İkinci kaynak işlemi gerçekleştirilirken kaynak sonrası ısıl işlem uygulanmamıştır. Aynı malzemelerle, aynı elektrotlarla, aynı kaynak yöntemleriyle ama farklı kalınlıklarda gerçekleştirilen kaynaklara ısıl işlem uygulamanın malzemelerin bazı mekanik özelliklerine olan etkisi ve gerilme giderme sonrası meydana gelen değişiklikler incelenmiştir. Elde edilen kaynaklı parçaların mekanik testleri olarak çekme testi, eğme testi, sertlik testi, çentik darbe testi gerçekleştirilmiş, makro görüntüleri çekilmiş, karşılaştırılmaları yapılmıştır. Sonuç olarak kaynak kalitesi üzerindeki etkiler araştırılmış ve sonuçlar verilen dolgu elektrotları ve çelik borularla kaynak işlemlerinin başarıyla gerçekleştirildiğini göstermektedir.

Anahtar Kelimeler

• A 333 Gr.6
• A350LF-2
• GTAW
• SMAW

Kaynakça

1. J.M. Tanzosh, Chapter A3: Piping Materials, in Piping Handbook, New York, McGraw-Hill, 2000.
2. Norsok Standard, M-001 Material Selection, Norwegian Petroleum Industry, Norway, 2004.
3. M. Stipanicev, F. Turcu, L. Esnault, O. Rosas, R. Basseguy, M. Sztyler, I.B. Beech, Corrosion of carbon steel by bacteria from North Sea offshore seawater injection systems: Laboratory investigation, Bioelectrochemistry 97, (2013), 76-88. https://doi.org/10.1016/j.bioelechem.2013.09.006
4. S. Papavinasam, Chapter 3 – Materials, Corrosion Control in the Oil and Gas Industry, 2014.
5. M.F. Ashby, Materials Selection in Mechanical Design, Burlington: Elsevier Publisher, 2005.
6. A.J. Bryhan, W. Troyer, Weldability of a low carbon Mo-Nb X-70 pipeline steel, Welding Research, 1980.
7. P. Smith, Piping Materials Selection and Applications, Burlington: Gulf Professional Publishing, 2005.
8. American Society for Testing and Materials (ASTM), ASTM A333: Standard specification for seamless and welded steel pipe for low-temperature service, American Society for Testing and Materials (ASTM), Washington, 2013.

9. Z. Wang, Y. Li, C. Chang, Application of automatic TIG welding for Yamal LNG process piping fabrication International Journal of Oil, Gas and Coal Engineering 6, (2018), 44-49. https://doi.org/10.11648/j.ogce.20180604.11
10. A.B. Nissan, K.C. Baker, Determination of the cause of low temperature charpy toughness values in ASTM A350 LF2 Flanges, Proceedings of the 28th ASM Heat Treating Society Conference, USA, 2015: pp. 342-349.
11. P.K. Ghosh, P.K. Singh, K.K. Vaze, H.S. Kushwaha, Characterisation of pipe welds and HAZ in primary heat transport system piping of pressurised heavy water reactors, Science and Technology of Welding and Joining, 9 (2004) 200-208.
12. M.E. Efzan, S. Kesahvanveraragu, J. Emerson, Microstructural characterization and hardness properties of A333 grade 6 low carbon steel in offshore platform pipelines, Journal of Advanced Research in Materials Science 2 (2014) 1-9.
13. E.S. Kayalı, C. Ensari, F. Dikeç, Metalik malzemelerin mekanik deneyleri, İTÜ Kimya-Metalurji Fakültesi, Ofset Atölyesi, İstanbul, 1996.
14. S. Fowler, A. Toumpis, A. Galloway, Fatigue and bending behaviour of friction stir welded DH36 steel, Int J Adv Manuf Technol 84, (2016), 2659-2669.
15. T.L. Dickerson, J. Przydatek, Fatigue of friction stir welds in aluminium alloys that contain root flaws, Int J Fatigue 25, (2003), 1399–1409.
16. I.V. Vlasov, A.I. Gordienko, V. M. Semenchuk, Heat treatment effect on structure and mechanical properties of gas metal arc-welded pearlitic steel, Russ Phys J, 67, (2024), 1590-1598. https://doi.org/10.1007/s11182-024-03286-y
17. X. Wang, D. Wang, L. Dai, C. Deng, C. Li, Y. Wang, K. Shen, Effect of post-weld heat treatment on microstructure and fracture toughness of X80 pipeline steel welded joint, Materials, 15(19), (2022), 6646.
18. K.A.M.B. Gonçalves, G.L. de Faria, R.H.M. de Siqueira, T.R. de Oliveira, M.S.F. de Lima, Heat treatment effects on the hardness and wear behavior of laser-welded AISI40 martensitic steel plates, Int J Adv Manuf Technol 114, (2021), 1155-1163.
19. C. Köse, R. Kaçar, The effect of preheat & post weld heat treatment on the laser weldability of AISI 420 martensitic stainless steel, Mater Design 64, (2014), 221-226.
20. L. Yu, K. Nishimoto, H. Hirata, K. Saida, Hardness prediction of the heat-affected zone in multilayer welded SUS316 stainless steel based on dislocation density change behavior, Metall Mater Trans A, 55, (2024) 1788-1803.
21. L.E. Svenson, B. Gretoft, Microstrcuture and impact toughness of C Mn weld metals, Welding Journal, (1990) 454-461.
22. A. Ilić, I. Miletić, R.R. Nikolić, V. Marjanović, R. Ulewicz, B. Stojanović, L. Ivanović, Analysis of influence of the welding procedure on Impact Toughness of welded joints of the High-Strength Low-Alloyed Steels, Applied Sciences 10(7), (2020), 2205.
23. C.F. Jatczak, D.J. Girardi, E.S. Rowland, On banding in steel, Transactions of the ASM 48, (1956), 279-305.
24. P.G. Bastien, The mechanism of formation of banded structures. Journal of the Iron and Steel Institute, 187, (1957), 281-291.
25. G. Evans, Effect of Si on the microstructure and properties of C-Mn all weld metal deposits, Metal Construction (1986).