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

Abstract

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.

Keywords

• A 333 Gr.6
• A350LF-2
• GTAW
• SMAW

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

Abstract

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.

Keywords

• A 333 Gr.6
• A350LF-2
• GTAW
• SMAW

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