Stainless steels as a solution for corrosion and erosion problems involving grains in agribusiness sector applications

Agricultural activities such as grain processing play a crucial role in Brazil's economy, contributing significantly to its gross domestic product (27.4% in 2021). The use of carbon steel equipment leads to considerable environmental and economic losses in agribusiness due to corrosion. This study explores the erosion-corrosion behavior of a dual-phase 11Cr and an 18Cr8Ni stainless steel (SS), compared to a mild (ASTM A36) and a high-strength carbon (AHSS) steel under conditions close to the agribusiness reality. The impact of corn particles as erosive component associated to pure water and chloride-containing environments was studied using a fog chamber, a topic until now unexplored in the literature. The methodology adopted is novel and explores the erosion-corrosion synergy in cumulative steps, aiming to shed light on the mechanisms of corrosion and wear that affect the materials in the agribusiness industry. The findings reveal that corn particles, despite their soft nature, can easily remove non-adherent corrosion products from the steel surface. In the deionized water medium, the impact of the soft particles can also shift the corrosion pattern of advanced high-strength steels from general corrosion to localized pitting damage reduzing the corrosion rates. The carbon and 11Cr steels showed the highest corrosion rates under the pure corrosion condition in both media. The erosion-corrosion process considerably reduced the corrosion rate, mainly in the deionized water medium for the carbon steels. An exception to this behavior was 18Cr8Ni steel, whose corrosion rates, however, were the lowest among the materials. Low-chromium stainless steel emerges as a cost-effective solution to erosion-corrosion challenges in the agribusiness segment.