Yüksek Basınçlı Sıcak Proses Geçiş Hatlarında Bağlantı Mikroyapı ve Mekanik Özelliklerinin Araştırılması

Abstract

Günümüzde önemi artan rafinerilerin ana bölümlerinin başında sıcak proses geçiş hatları (SPG) yer almaktadır. SPG’ler rafinerilerde ham petrol vakum distilasyon ünitesi ve diğer ünitelerde bulunan vakum hatları olarak da isimlendirilen hatlardır. SPG hatlarında meydana gelebilecek hatalar insan ve çevre üzerinde olumsuz etkilerin oluşacağı büyük endüstriyel kazalara neden olmaktadır. Bu hatlarda sızdırmazlığın sağlanması, ısıl genleşme problemlerinin önüne geçilebilmesi ve ekonomik bir bağlantı yöntemi olduğu için birleştirme işlemlerinde kaynak yöntemleri tercih edilmektedir. SPG hatlarında ortalama 14 MPa basınç altında ve yaklaşık 640 °C sıcaklıktan 30 °C sıcaklığa kadar akışkan transferinin sağlandığı fırın giriş çıkış hatları yer almaktadır. Fırın içinde SS 316L paslanmaz çelik, fırın dışında ASTM A106 Grade B düşük karbonlu çelik kullanılmaktadır. Bu çalışma kapsamında fırın giriş-çıkış hatlarında TİG kaynak yöntemi ile birleştirilen bağlantılar incelenmiştir. Endüstriyel uygulamalarda sıklıkla tercih edilen parametrelerin hangilerinin en güvenli kaynak bağlantılarını meydana getirdiği imalatçılar tarafından belirsizliğini korumaktadır. Bu çalışmada deneyler yapılarak en güvenli kaynak parametreleri tespit edilmiştir. En iyi sonuçlar; eğme deneyinde kaynak bölgesinde çatlak oluşmaması ve 678 MPa çekme mukavemeti ile S6 nolu numuneden elde edilmiştir. S6 nolu numune kök, sıcak, dolgu ve kapak pasolarının sırasıyla 90, 150, 165 ve 170 A akımda gerçekleştirilen numunedir.

Keywords

• Sıcak proses hatları
• TİG
• SS 316L
• A106 Grade B
• Mikroyapı
• Mekanik özellikler

Investigation of Connection Microstructure and Mechanical Properties in High Pressure Hot Process Transition Lines

Abstract

Hot process transition lines (HPTLs) are among the most important parts of refineries, with their increasing importance today. HPTLs are also known as vacuum lines located in the crude oil vacuum distillation unit and other units within refineries. Failures in HPT lines can lead to major industrial accidents that can have adverse effects on humans and the environment. Welding is preferred in joining processes in these lines because it ensures leak-TİGhtness, prevents thermal expansion problems, and is an economical joining method. HPT lines include furnace inlet and outlet lines, where fluid transfer occurs from approximately 640°C to 30°C under an average pressure of 14 MPa. SS 316L stainless steel is used inside the furnace, and ASTM A106 Grade B low-carbon steel is used outside the furnace. In this study, joints joined by TİG welding in furnace inlet and outlet lines were invesTİGated. It remains unclear by manufacturers which of the frequently preferred parameters in industrial applications create the safest welded joints. In this study, the safest welding parameters were determined through experiments. The best results were; No cracks were formed in the weld area in the bending test and a tensile strength of 678 MPa was obtained from sample S6. Sample S6 is the sample in which the root, hot, filler and cover passes were performed at 90, 150, 165 and 170 A currents, respectively.

Keywords

• Hot process lines
• TİG
• SS 316L
• A106 Grade B
• Microstructure
• Mechanical properties

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