Green Ferritic Stainless Steel: A Sustainable, Advanced and Cost-Effective Solution for the Concrete Mixer Drum

Abstract

AbstractThe use of stainless steel has been increasing in sectors where mechanical wear acts in conjunction with corrosion, such as mining and agribusiness, particularly biofuels. This replacement has led to an increase in the service life and a reduction in the weight of the structures, significantly improving the sustainability of these sectors. When using materials having a longer functional life, the production chain is more environmentally friendly because less coke and less iron ore are needed. In the case of green steels, i.e., steel produced with charcoal instead of coke and entirely recyclable, the Life Cycle Assessment (LCA) is even more favourable. Due to the unique supply chain, certified by the Forest Stewardship Council, Aperam South America is the only global producer of steels that uses 100% charcoal from proprietary eucalyptus forests instead of mineral coke. Laboratory and field tests were performed that compared abrasion-corrosion of carbon steels, advanced high-strength steels, weathering steel and nine different green stainless steels. Initially, rubber wheel and free-ball microabrasion tests were performed. In addition, a laboratory device approaching actual service conditions was built. In the field, samples were placed in sand processing equipment and inside a concrete mixer drum in a truck. Both the field and laboratory samples were collected and extensively analysed using SEM and hardness tests. Finally, a complete green stainless-steel concrete mixer drum entirely manufactured from green 410M steel was built, adapted to a truck and field-tested for five years (beginning in 2015). The useful life of the equipment increased up to three times compared to that made with standard carbon steel. It is worth noting that the concrete mixer made of green steel still preserves 70% of its thickness, predicting production of 72,000 m3 of concrete and work for 12 years without the need for maintenance, which makes it the most sustainable, advanced, and cost-effective solution for the concrete mixer drum.KeywordsSDG 13 and SDG 15SustainabilityGreen stainless steelAbrasion-corrosion; synergy; ferritic stainless steelConcrete mixer drum