ANALISA KETAHANAN STAINLESS STEEL AISI 308 TERHADAP PITTING CORROSION DENGAN MENGGUNAKAN METODE E-CRITICAL TEMPERATURE TEST FOR STAINLESS STEEL ASTM-G48

Stainless Steel merupakan salah satu material logam penting yang sering sekali digunakan dalam kehidupan sehari-hari di berbagai bidang. Walaupun begitu, Stainless Steel tidak dapat terhindarkan dari proses korosi dikarenakan adanya berbagai faktor yang mempengaruhi cepatnya proses korosi, seperti konsentrasi oksigen, pH, dan temperatur. Tujuan dari penelitian ini adalah mengetahui ketahanan logam Stainless Steel 308 dengan faktor yang ada pada proses korosi. Standar pengujian yang digunakan adalah ASTM-G48 dengan mengunakan 6% larutan ferric chloride (FeCl3) dan konsentrasi Cl- melalui penerapan lima kondisi temperature (10oC, 15oC, 20oC, 30oC, 35oC) selama 24 jam. Setelah itu dilakukan pengujian SEM dan pengamatan visual NDT. Berdasarkan perhitungan CPT menggunakan rumus ASTM G48, Stainless Steel 308 memiliki CPT sebesar 8.02oC. Hasil perhitungan luas area korosi spesimen 10oC, 15oC, 20oC, 30oC, dan 35oC diantaranya 0 cm2, 0 cm2, 2.648 cm2, 3.155 cm2, dan 2.788 cm2. Pada spesimen temperature 10oC dan 15oC tidak adanya proses pitting menunjukkan korosi pitting terjadi kisaran 15oC sampai 20oC sehingga material dinyatakan layak pakai. ========================================================= Stainless Steel is one of the important metal materials that is often used in daily life in various fields. Even so, stainless steel cannot be avoided from the corrosion process because of the factors that affect the speed of the corrosion process, such as oxygen concentration, pH, and temperature. The purpose of this research is to determine the resistance of the metal stainless steel 308 with the factors that exist in the corrosion process. The test standard used is ASTM-G48 using 6% ferric chloride (FeCl3) solution and the Cl-concentration through the application of five temperature conditions (10oC, 15oC, 20oC, 30oC, 35oC) for approximately 24 hours. After that, SEM examiners and visual NDT observations were carried out. Based on the CPT calculation using the ASTM G48 formula, Stainless Steel 308 has a CPT of 8.02oC. The results of the calculation of the pitting area of 10oC, 15oC, 20oC, 30oC, and 35oC specimen corrosion area were 0 cm2, 0 cm2, 2,648 cm2, 3,155 cm2, and 2,788 cm2. At 10oC and 15oC specimen temperatures there is no process that shows corrosion occurring in the range of 15oC to 20oC so that the material is declared fit for use