Corrosion Study of AISI 304, AISI 321 and AISI 430 Stainless Steels in a Tar Sand Digester

摘要

This work has investigated the corrosion properties of three types of stainless steels in a tar sand digester environment with the aim of establishing their relative resistances in the environment. The corrosion experiments for the stainless steels were conducted by the non-electrochemical immersion technique with corrosion rates expressed in mils per year (mpy). The spectroscopy analysis of the Nigerian tar sand was done by the energy dispersive x-ray analysis. The surface study of the corroded stainless steels was accomplished via a scanning electron microscopy (SEM) to reveal the form of corrosion. The results of the corrosion experiments show that all the stainless steels have a relatively low corrosion rates (<5mpy). The SEM analyses of their corroded surfaces however revealed great tendency in them to exhibit crevice and pitting corrosions. On the basis of resistance to the two forms of corrosion the AISI 321 stainless steel exhibited the best resistance in the environment.