Pengaruh temperatur sensitisasi dan variasi stress terhadap laju korosi SS 409 pada lingkungan salt spray

Maulana, Faris Hizrian (2015) Pengaruh temperatur sensitisasi dan variasi stress terhadap laju korosi SS 409 pada lingkungan salt spray. Undergraduate thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Korosi intergranular merupakan permasalahan yang sering terjadi pada stainless steel. Hal ini dipicu karena adanya proses sensitisasi yang menyebabkan terbentuk presipitasi karbida pada batas butir yang menyebabkan berkurangnya kadar Cr pada butir yang berakibat stainless steel menjadi rentan terhadap korosi. Ferritic stainless steel 409 merupakan material yang biasa digunakan pada heat exchanger maupun exhaust pada kendaraan otomotif dimana sering mendapatkan temperatur yang tinggi. Jika terdapat internal stress yang merupakan hasil welding maupun cold working pada material tersebut dapat menyebabkan laju korosi menjadi lebih tinggi. Penelitian ini bertujuan mempelajari laju korosi pada spesimen ferritic stainless steel tipe 409 yang telah mengalami proses sensitisasi serta mendapatkan tegangan aplikasi sebesar 20% dan 40% yield stress pada lingkungan salt spray. Hasil Metalografi dan SEM menunjukkan adanya senyawa TiC yang merupakan presipitat karbida yang muncul pada spesimen dengan temperatur anil 550oC sampai 850oC yang menyebabkan laju korosi yang lebih tinggi dari spesimen lain. Pengujian ini menunjukkan bahwa semakin tinggi temperatur sensitisasi dan semakin besar stress yang diberikan, laju korosi akan semakin meningkat.

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Intergranular corrosion is a common problem that often occurs in stainless steel. It is triggered due to sensitization that led to form carbide at grain boundaries that can reduce Cr content on grains that resulting the stainless steel becomes susceptible to corrosion. Ferritic stainless steel type 409 is commonly used in the heat exchanger and exhaus on automotive which often operated at elevated temperature. If there exist an internal stress as the result of welding or cold working, that can cause the material become more susceptible to corrosion and as the result, corrosion rate becomes higher. This research is focused to study the rate of corrosion on the 409 ferritic stainless steel which has undergone sensitization process and an applied stress by 20% and 40% of its yield stress in salt spray environment. Metallography and SEM results indicate that the TiC carbide precipitates exist on specimen with annealing temperature of 550oC to 850°C which causes the corrosion rate is higher than the other specimens. The study showed that the higher the temperature of sensitization and applied stress, the higher the corrosion rate will be.

Item Type:	Thesis (Undergraduate)
Additional Information:	RSMt 620.112 23 Mau p
Uncontrolled Keywords:	SS 409; Sensitisasi; Bent-Beam; Laju Korosi
Subjects:	T Technology > TN Mining engineering. Metallurgy > TN690 Metallography. Physical metallurgy
Divisions:	Faculty of Industrial Technology > Material & Metallurgical Engineering > 28201-(S1) Undergraduate Thesis
Depositing User:	- Taufiq Rahmanu
Date Deposited:	01 Nov 2018 03:35
Last Modified:	01 Nov 2018 03:35
URI:	http://repository.its.ac.id/id/eprint/59928

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