The effect of fuel on the corrosion rate of commercial steels- a field study

Abstract

This study focuses on investigating the effects of long-term exposure of different steel alloy samples in the superheater region of two boilers, situated in Biganos (Biomass fuel) and Grenoble (waste fuel). The purpose of this study is to analyze the corrosion mechanisms of various commercially used stainless-steel alloys and compare their costs to fulfill the goal of determining the most suitable alloy in terms of lifetime and maintenance cost. The value of this research is based upon the increasing global need for fuels in power and heat production as well as the need to solve both environmental and economic challenges associated with fossil fuels. It is of great value that the construction of future powerplants and especially boilers is constructed of high temperature corrosion resistant materials, both regarding the economical perspective of the companies but also concerning the global goals of environmental sustainability. The samples were analyzed using Scanning Electron Microscopy (SEM) together with Energy Dispersive X-ray Spectroscopy (EDX) in order to calculate material loss, due to corrosion, and chemical composition of attached deposit layers. Additionally, Ion Chromatography (IC) was used to investigate the presence of chlorine and sulfur containing compounds. This study presents data which indicates a great variation in corrosion resistance between steel alloys. Some samples showed signs of great material loss together with a dense and solid deposit layer and other samples showed little to no material loss. In conclusion the material with the most suitable properties for the two boilers is AISI TP310H with no significant material loss and a relatively low price.