Open AccessBehavior of Phosphate Inhibitor on Pitting Corrosion Resistance of Cr-Mo Steel
Author(s) -
Sri Hastuty,
Muhammad Awwaluddin
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/536/1/012025
Subject(s) - corrosion , pitting corrosion , boiler (water heating) , metallurgy , materials science , boiler water , phosphate , corrosion inhibitor , polarization (electrochemistry) , nuclear chemistry , chemistry , waste management , organic chemistry , engineering
Trisodium phosphate (TSP) and disodium phosphate (DSP) inhibitors are widely used in industrial area, for example in boiler and condenser system. Their primary uses as scaling inhibitor through anodic and cathodic reaction. Therefore, concentration of TSP and DSP is a dominant factor to intended service; it could be advantage if the concentration is proportional, or on the contrary, destructive if the concentration is not proportional because it will drive localized corrosion on tube boiler made from Cr-Mo steel. In this research, type of localized corrosion will be focused on pitting corrosion. To gain maximum protection effect of TSP and DSP inhibitors, which is also for controlling corrosion as destructive process, optimum concentration of inhibitor was determined. To investigate the effect of concentration variation of TSP and DSP on pitting resistance Cr-Mo steel and optimum concentration of TSP and DSP as inhibitor, pitting corrosion tendency by using cyclic polarization was measured. The result was TSP and DSP retarded pitting corrosion by adsorbed on Cr-Mo steel surface. It was also found that inhibitor optimum concentration range is between 20.000 ppm TSP + 1.000 ppm DSP. 100.000 ppm TSP + 1.000 ppm DSP (10%V), which pH optimum range is between 11 to 12.