High temperature corrosion of steels used in petroleum refinery heaters

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Metalurji ve Malzeme Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2005

Öğrenci: ABDELRAHMAN SULTAN

Danışman: İSHAK KARAKAYA

Özet:

The oxidation of three different steels used in the construction of petroleum refineryheaters was investigated by using thermogravimetric analysis technique (TGA). C-5,P-11, and P-22 steel samples were tested in two different oxidizing environments; air and CO2+N2+H2O (that simulates the combustion products of natural gas) at two different temperatures; 450oC and 500oC. In air oxidation P-22 had the best oxidation resistance among the three steels at two temperatures. In CO2+N2+H2O environment,C-5 possessed better oxidation resistance than P-22 and P-11. Analyses of oxidation products by using optical microscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were carried out to correlate TGA results to oxide composition and morphology. Lower oxidation rate of P-22 in air was explained with reference to the formation of Cr-O phase. Analytical rate equations showed that all the steels obeyed parabolic rate equation during oxidation and no transition was observed