ABSTRACT
The purpose of this work was to evaluate the influence of the average grain size on the corrosion susceptibility of AISI 316L austenitic stainless steel, which is widely used in welded joints, at room temperature and at very low temperatures (cryogenic conditions) because it has excellent corrosion resistance and good ductility. For this, samples were thermally simulated on a Gleeble 3800 at temperatures of 900°C and 1200°C under the residence time of 0, 5, 20 and 100 seconds, controlling the cooling rate to around 20°C/s followed by metallography and corrosion analysis using linear polarization electrochemical techniques using a solution of 3,5% sodium chloride (NaCl). In addition, tests were performed by x-ray analysis on samples of greater and lesser susceptibility to corrosion for microstructural verification. The results showed that the samples submitted to 1200ºC presented a bigger increase in the average grain size in relation to the samples of 900ºC, having a lower susceptibility to corrosion, except for the condition of 1200ºC to 100s. However in the samples with 1200ºC to 100s, carbides were detected by X-ray analysis and finally, the corrosion phenomena were observed by pitting in all samples.
Keywords
AISI 316L; Corrosion; Average grain size; Thermal simulation; Gleeble
