<![CDATA[Penelitian mengenai penggunaan ekstrak metanol daun kaliandra sebagai inhibitor korosi logam besi telah dilakukan. Tujuan dari penelitian ini adalah untuk mengetahui senyawa metabolit sekunder yang terkandung dalam ekstrak daun kaliandra (Calliandra calothyrsus M.) dan kondisi optimum pada variasi waktu perendaman, konsentrasi dan suhu pada proses inhibisi logam besi dalam media HCl. Ekstrak daun kaliandra diperoleh melalui ekstraksi maserasi dengan pelarut metanol. Uji inhibisi korosi dilakukan menggunakan metode pengurangan berat dengan variasi waktu perendaman, konsentrasi ekstrak daun kaliandra, dan suhu untuk mengetahui laju korosi per tahun dan % efisiensi inhibisi. Hasil penelitian menunjukkan bahwa ekstrak metanol daun kaliandra mengandung senyawa metabolit sekunder alkaloid, flavonoid, tanin, dan saponin. Kondisi optimum untuk proses inhibisi logam besi pada media korosif HCl dengan ekstrak daun kaliandra diperoleh pada waktu peredaman 6 hari dengan efisiensi inhibisi dan nilai laju korosi sebesar 86,49% dan 0,00119 mm/tahun, serta pada konsentrasi 13.000 ppm dan suhu 26? dengan efisiensi inhibisi dan nilai laju korosi sebesar 91,60 % dan 0,00073 mm/tahun. Pada perendaman menggunakan variasi suhu, semakin tinggi suhu yang digunakan maka efisiensi inhibisinya semakin menurun dan laju korosinya semakin meningkat sehingga logam besi mengalami korosi lebih cepat. Kata kunci: Besi, Korosi, Ekstrak Metanol, Inhibitor, Daun Kaliandra. ABSTRACT In this research, the use of methanol extract from calliandra leaves as an iron metal corrosion inhibitor has been conducted. The purpose of this study was to determine the type of secondary metabolite compounds contained in the extract of calliandra leaves (Calliandra calothyrsus M.) and to determine the optimum conditions at variations (immersion time, concentration, and temperature) in the process of iron metal inhibition using calliandra leaf extract in the HCl corrosion media. The calliandra leaves were extracted using the maceration method with a methanol solvent. The corrosion inhibition test was carried out using the weight loss method with variations in soaking time, the concentration of calliandra leaf extract, and temperature to determine the optimum corrosion rate per year and inhibition efficiency. The results showed that the methanol extract of calliandra leaves contained secondary metabolite compounds of alkaloids, flavonoids, tannins, and saponins. The optimum conditions for the inhibition process of iron metal in HCl corrosive media with calliandra leaf extract were at the soaking time of 6 days with the inhibition efficiency and corrosion rate of 86.49% and 0.00119 mm/year, and the concentration of 13,000 ppm and temperature of 26? with the inhibition efficiency and corrosion rate of 91.60% and 0.00073 mm/year. In immersion using temperature variation, the higher the temperature used, the lower the inhibition efficiency and the higher the corrosion rate obtained so that the iron metal corroded faster. Keywords: Iron, Corrosion, methanol extract, Inhibitor, Calliandra Leaf.]]>
