Ekstrak Daun Pepaya sebagai Inhibitor Korosi pada Baja AISI 4140 dalam Medium Air Laut

Abstract

One of the inhibitors are derived from natural papaya extract. The utilization ofnatural products extracts as corrosion inhibitors for corrosion inhibitors chemical synthesis of the most dangerous, expensive and environmentally unfriendly. Thisstudy aims to determine the value of the corrosion rate of the steel using inhibitorsof papaya leaf extract and compare the corrosion rate between using inhibitors andwithout inhibitors on steel in seawater as a corrosion media, as well as determinethe inhibition efficiency. Methods of testing performed in this study, the method oflosing weight by using a variation of the longer soaking time (4, 8, 12, 16, 20, 24,28, 32, 36, and 40 days). Percent yield of papaya extract obtained in the amount of10.612%. The results showed that the effect of soaking time on the corrosion rate,which by using inhibitors of corrosion rate is slower than without inhibitor. Great-est value of the corrosion rate by using the inhibitor at 4 days of soaking 28,4.10-6gram/mm2.day and lowest value of the corrosion rate of 6,8.10-6 gram/mm2.day onsoaking of 36 days, while the biggest value of the corrosion rate with without in-hibitor that is equal 31,1.10-6 gram/mm2.day on soaking 4 days and the lowest valueof the corrosion rate on soaking 8,5.10-6 gram/mm2. at 40 days. Inhibition effi-ciency increases with increased soaking time and achieve optimum value of inhibi-tion efficiency of 21.59% at 36 days immersion.

Keywords: corrosion inhibitor, maceration, natural extract ingredients (papaya),the rate of corrosion