The Friction Hydro-Pillar Process (FHPP) is an innovative process that has been recently studied regarding its possible in situ repair applications. There is still no literature about usage of the FHPP on duplex stainless steel (DSS) base materials to smaller forces than 25 kN. The investigation on DSS processing is crucial due his wide variety of critical uses in pipes and storage structures applied in chemical industry plants, where usual welding processes may lead to safety concerns. The aim of this study is to qualify the processing of SAF 2205 (UNS 31803) duplex stainless steel welded joints using FHPP as feasible repair procedure. For this, the studied samples were welded applying a range of axial forces. The welded joints were characterized by, α/γ phase ratio, intermetallic quantification, austenite spacing measurement, microhardness profile and microstructural qualitative studies. The results showed the efficiency in repair of the FHPP process on the production of DSS joints according with the material recommendations from the standard DNV-RP-F112.

Resumo Uma das principais exigências de uma prótese de quadril, além da biocompatibilidade, é que ela tenha um bom desempenho em fadiga. As propriedades de fadiga estão diretamente ligadas com a microestrutura do material, sendo assim, entendem-se as exigências microestruturais determinadas por normas para próteses. A microestrutura passa a ter um papel importante na qualidade desses componentes; e sendo ela diretamente influenciada pelos processos de fabricação precedentes, tais processos também devem ser rigorosamente controlados. Nesse trabalho foi analisada uma prótese de quadril, fabricada a partir de uma liga de aço inoxidável, que fraturou por fadiga durante o uso. A análise foi conduzida pelo uso de lupa, microscópio eletrônico de varredura, análise química e análise metalográfica. Foi verificado que apesar da análise química estar dentro dos limites determinados pela norma ABNT NBR ISO 5832-1, a microestrutura estava heterogênea, devido ao processo de forjamento, comprometendo o desempenho em fadiga do componente. Palavras-chave: Análise de falha; Prótese de quadril; Aço inoxidável ABNT NBR ISO 5832-1; Fadiga. THE IMPORTANCE OF MICROSTRUCTURE ON THE PERFORMANCE OF HIP PROSTHESIS Abstract One of the main requirements of a hip prosthesis, besides biocompatibility, is that it has a good fatigue performance. The fatigue properties are directly connected with the microstructure of the material, under these circumstances, is understood the standards specifications for microstructural in prosthetics. So, the microstructure becomes important in the quality of these components, and being it, directly influenced by the fabrication processes, such processes must also be rigorously controlled. In this study was analyzed a hip prosthesis manufactured from a stainless steel alloy that fractured by fatigue during use. The analysis was conducted by using a stereoscope, scanning electron microscopy, chemical and metallographic analysis. It was found that chemical analysis was as determined by ABNT NBR ISO 5832-1 while the microstructure was heterogeneous, due to the forging process, damaging the fatigue performance of the component.