Corrosion resistance study of 439L ferritic stainless steel subjected to high temperature variation
No Thumbnail Available
Date
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Cogent Engineering
Abstract
Description
for the production of exhaust mufflers due to corrosion failures associated
with their operating lifespan and conditions of application. Corrosion vulnerability
of as received and heat treated (500oC and 1000oC) 439 L ferritic
stainless in 3.5 M H2SO4 electrolyte at 0% to 6% NaCl concentration was evaluated
with potentiodynamic polarization, potentiostatic measurement, open circuit
potential measurement, and optical microscopy characterization. Potentiodynamic
polarization results show heat treatment improved the general corrosion resistance
of the steel. Heat treated 439 L steel at 500°C displayed the lowest corrosion rate
trailed by the heat treated steel at 1000°C. However, potentiostatic measurement
shows that heat treatment decreases the resistance of the steel to localized corrosion
deterioration from inspection of the metastable pitting current and passivation
potential values. Results from open circuit potential measurement show heat
treatment increases the thermodynamic tendency for 439 L steel to corrosion while
improving its corrosion resistance. Optical images of the as-receive and heat treated
steels show the presence of numerous corrosion pits and corrosion along the grain
boundaries. However, the extent of deterioration is significantly higher for the asreceived
steel.
Keywords
TJ Mechanical engineering and machinery