Synergistic effect of essential oil distillates on the corrosion protection of GX4CrNiMo16-5-1 stainless in acid-chloride electrolyte
No Thumbnail Available
Date
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Description
The inhibition capability of admixed rosemary oil with cinnamon cassia oil (RC), and
grapefruit oil with lemongrass oil (GL) on GX4CrNiMo16-5-1 martensitic stainless steel
(GX4ST) corrosion was studied in 6 M H2SO4/3.5% NaCl electrolyte by potentiodynamic
polarization and optical microscopy characterization. Results show both admixed distillates
performed effectively on GX4ST. The corrosion rate of GX4ST without the distillates at 2.82
mm/y significantly decreased to average value of 0.04 mm/y and 0.05 mm/y analogous to
average inhibition efficiency of 98.64%and 98.23%for RC and GL compound. The oil distillates
exhibit consistent anodic corrosion inhibition behavior at all concentrations studied. Corrosion
thermodynamic calculations showed the distillates chemisorbed on the martensitic steel with
Gibbs free energy values greater than -46.01 Kjmol-1with respect to Langmuir isothermequation
which indicates negligible of lateral interaction effect among inhibitor molecules and surface
coverage protection mechanism. Optical image representations of GX4ST after corrosion
without the distillates showed severe surface degradation of general and localized corrosion. This
contrast the images of the inhibited steel surface which were closely similar to the steel image
before corrosion.
Keywords
TJ Mechanical engineering and machinery, TP Chemical technology