Perilaku inhibisi organik terhadap baja karbon rendah di lingkungan HCl 1M yang berupa ekstrak ubi ungu, telah diteliti dengan pengaruh waktu perendaman (3, 6, 9, dan 12 hari) dan menggunakan metode kehilangan berat. Penggunaan ekstrak ubi ungu sebagai inhibitor organik, karena terdapat kandungan antioksidan yang dapat memperlambat laju korosi. Konsentrasi ekstrak ubi ungu yang digunakan bernilai sama untuk semua waktu perendaman, senilai 6 ml. Hasil penelitian ini menunjukkan ekstrak ubi ungu merupakan inhibitor korosi yang efektif untuk baja karbon rendah di lingkungan asam kuat, hal ini dibuktikan dengan dapat menghambat laju korosi secara signifikan dengan efisiensi sebesar 77,96% - 84,88% selama waktu rendam 3 -12 hari.

---

Behavior of organic inhibition on low carbon steels in HCl 1M in purple sweet potato extract, has been shown to result with the effects of submersion time (3, 6, 9, and 12 days) and investigated by the weight loss method. Purple sweet potatoes as an organic inhibitor because antioxidant compounds contained in purple sweet potatoes which can reduce the corrosion rate. Extract concentration and immersion time of purple sweet potatoes have the same equation, which are 6 ml. The research results indicate that extract of purple sweet potatoes was an effective corrosion inhibitor for low carbon steels in acidic environment, this results is proved that could reduce the corrosion rate significantly with inhibition efficiency of 77,96%-84,88% with immersion times ranging between 3-12 days.