Caracterização química e metalográfica dos aços inoxidáveis de implantes removidos de pacientes

Abstract

Objective: This study examines the chemical and metallogra-phic composition (microstructure, grain size, inclusion content) of austenitic stainless steel developed as biomaterials for used in the manufacture of orthopedic implants. Method: An analysis was carried out of twelve implants removed from patients affected by inflammation. Chemical analyses were carried out using Opti-cal Emission Spectrometry and Energy Dispersive Microanalysis (EDS), and the grain size was determined by optical microscopy and scanning electron microscopy (SEM) according to ASTM Standard E 1382 97. Results: It was observed that all the implants had a larger grain size than is recommended by the Standard. The presence of delta ferrite was also observed in ten of the twelve implants removed, which according to ASTM Standard F138-92, should not be perceived microscopically under magnification of 100x. Conclusions: In eight cases, there is a strong indication that the inflammation was triggered by pitting corrosion. Level of Evidence: Level III, Systematic review of studies.