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The microstructure and electrochemical properties of 316L stainless steel were investigated after two conditions: aged at 640°C for 100,700 h and solution annealed at 1050°C for 2 h. While the aged samples were obtained from a pipe of a petrochemical reactor plant that was in service, the solution annealing was carried out in a conventional laboratory furnace. After aging, the precipitates present in decreasing order of quantity were sigma, Laves phase, and M 23 C 6 . After solution annealing, the microstructure was full austenitic. These results were in agreement with equilibria phase simulation with Thermo-Calc software. Intergranular corrosion susceptibility, evaluated by means of the single loop electrochemical potentiokinetic reactivation technique and Practice A of ASTM 262, indicated a preponderant role for the sigma precipitate. The pitting potential (E pit ) was evaluated through potentiodynamic polarization curves in 0.6 M NaCl and electrochemical impedance spectroscopy was performed at the corrosion potential to complement the information about the corrosion resistance.

Resumo Um tubo soldado de aço inoxidável austeníticoAISI 316L com diâmetro nominal de 8 polegadas foi exposto por cerca de 100.700 horas a 640ºC, em um reator de uma planta petroquímica.As modificações na microestrutura, nas propriedades mecânicas e na resistência à corrosão foram investigadas e os resultados iniciais são apresentados neste trabalho. As análises revelaram a formação de fasesigma nos contornos e no interior dos grãos. A precipitação causou aumento da dureza, dos limites de escoamento e de resistência e diminuiçãona ductilidade, na tenacidade e na resistência à corrosão intergranular.. Palavras-chave:AISI 316L; caracterização microestrutural; fases intermetálicas; propriedades mecânicas e de corrosão.

The presence of crystalline defects, including dislocations and pipeline defect, is detrimental to both the processing and the intrinsic quality of semiconductor devices. The electrical parametric or functional failures generated by those defects require accurate identification and proper classification in a continuous improvement mindset. Depending on the failure analyst choice of the investigation technique, the distinction between a dislocation and a pipeline defect can be difficult. In this paper, based on case studies of mixed-mode devices, the various electrical and physical FA investigation techniques are explored and compared. From an electrical investigation standpoint, fault localization techniques will be reviewed (Thermal Laser Stimulation and Photon Emission Microscopy) as well as the direct electrical measurements means (external measurement and nanoprobing AFP). From a physical analysis standpoint, the use of various methods after deprocessing will be considered: top down delineation etch, Atomic Force Microscopy (AFM), Scanning Microwave Microscopy (SMM), and Transmission Electron Microscopy (TEM). The position of the defect as well as its physical signature observed through the various methods will determine its proper classification and will determine the appropriate corrective actions. The paper will be concluded with a discussion on the physical differences between a dislocation and a pipeline defect, as well as insights into the wafer fab manufacturing process.