Damage of Stainless Steel Components by Olive Paste

Failure of equipment for processing olives interrupted oil production after only 3 weeks in service. Macroscopic and microscopic analyses were used in the present investigation to analyze damaged surfaces. Observations and data suggest that failure was induced via tribocorrosion with a predominance of mechanical damage. This damage is attributed to abrasive wear combined with corrosion of AISI 304L stainless steel in olive paste (seed particles and pulp) mixed with tap water. Microscopic observations revealed fracture and localized plastic deformation in the damaged area along with a tribologically transformed structure and work-hardened surfaces. The tribological behavior of AISI 304L was determined using a pin-on-disc tribometer, and these results were compared to damage on the olive processing equipment. The steel was sensitive to tribo-oxidation, mostly due to abrasion by seeds and steel wear particles, and somewhat due to corrosion reactions with the environment.