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Pitting susceptibility of AISI 304 stainless steel after cold rolling
Autor
CORREA, OLANDIR V.
OLIVEIRA, MARA C.L. de
ANTUNES, RENATO A.
CONGRESSO BRASILEIRO DE CORROS??O, 34.; INTERNATIONAL CORROSION MEETING, 5th.; CONGRESO IBEROAMERICANO DE CORROSI??N Y PROTECCI??N, 10th.; CONCURSO DE FOTOGRAFIA DE CORROS??O E DEGRADA????O DE MATERIAIS, 19.; EXPOSI????O DE TECNOLOGIAS PARA PREVEN????O E CONTROLE DA CORROS??O, 34
Resumen
The austenitic grade AISI 304 stainless steel is traditionally employed for processing
equipment in chemical plants due to its relatively good corrosion resistance and mechanical
stability. However, it is susceptible to pitting corrosion due to chloride attack which can lead
to catastrophic failures during operation. Cold rolling of the metallic sheets used to construct
equipment such as tanks and pressure vessels can further aggravate the situation by increasing
the material???s susceptibility to localized corrosion. In this work the pitting corrosion
resistance of cold rolled AISI 304 stainless steel plates was assessed using
chronoamperometric curves and potentiodynamic polarization curves. Cold rolling was
performed in a two-roll mill at room temperature, achieving thickness reductions ranging
from 10% to 70%. The presence of pits on the surface of the samples was assessed using
optical microscopy. The onset of pitting corrosion was closely related to the strain level of the
rolled plates. There was a steep decrease of resistance to localized attack as the thickness
reduction increased.