PENGENDALIAN LAJU KOROSI BAJA A36 DALAM MEDIUM AIR LAUT, AIR HUJAN, DAN AIR TAWAR MENGGUNAKAN INHIBITOR EKSTRAK DAUN PEPAYA DENGAN PENGUJIAN FOTO MIKRO

Abstract This study aims to determine the rate of corrosion produced on steel A36 by adding inhibitor papaya leaf extract and also know the efficiency of papaya leaf extract is optimal on steel A36. The corrosive medium used in this study was sea water, rainwater, and fresh water. Steel is immersed in corrosive medium with the addition of inhibitor and without inhibitor with long immersion ie 6 days, 12 days, 18 days. The longer the immersion time without the use of inhibitor the corrosion rate increases and the longer the immersion using the inhibitor the corrosion rate decreases. The optimal efficiency value is obtained at 18 days soaking where the water is 68,88%, rain water 72,09%, fresh water equal to 72,97%. This suggests that papaya leaf extract inhibitors are efficient in controlling the corrosion rate. From microstructure photo analysis of A36 steel surface showing steel surface with addition of papaya leaf extract less corrosion