CORROSION FAILURE ASSESSMENT ON AISI 310S STEEL USED AS SUPPORT OF REFRACTORY CONCRETE PANELS IN A CLINKER COOLER

Abstract

This article presents the corrosion failure assessment on AISI 310 Steel, used as support of refractory concrete panels in a Clinker cooler under a combination of high temperatures and atmospheres with high concentration of sulfur and carbon. It was  performed  a  microstructural  analysis  by  scanning  electron  microscope  with  energy-dispersive  X-Ray  Spectrometer and by optic microscopy techniques. Furthermore it was used Raman spectroscopy in order to determinate the compounds formed in the rust layers. To understand the proposed corrosion mechanism, a thermodynamic simulation was performed on the basis of the 310S steel alloy main elements and temperatures between 700 and 1100 °C in an atmosphere mostly compound by sulfur and low oxygen. The results demonstrate that the material degradation  occurred due to a combined process of carburation and sulfidication. As a result of these processes, on one side, it was the impoverishment of chrome in  some  areas  due  to  the  formation  of  carbides,  on  the  other  side,  some  nickel  sulphides  compunds  emerge  as  eutectic  compounds (Ni-N3S2) with melting points lower than 800 ºC, which under this conditions, produce losses of material at the expense of their mechanical properties.