Analysis of electrochemical corrosion performance of 316L stainless steel fabricated and textured by selective laser melting

Abstract

Textured surfaces were used to increase the electrochemical corrosion resistance of the laser powder bed fusion, corrosion performance, DC corrosion and electrochemical impedance spectroscopy techniques were examined. Corrosion resistance could be optimized as a result of changing the surface energy on modified surfaces and eliminating selective laser melting (SLM)-induced morphological discontinuities. The corrosion resistance of optimum textured surfaces is higher than that of forged samples. Results close to texture-free surface performance were obtained on surfaces where texture density reached maximum. Increasing texture weakened the corrosion resistance. Thus the best corrosion resistance; icorr = 156 nA/cm2 with Ecorr = −327 mV observed at 5CR. Material losses are 49.40 mpy × 10−3 for 5CR, 63.48 mpy × 10−3 for 5SQ, 382.60 mpy × 10−3 for 15CR, 63.33 mpy × 10−3 for 15SQ, 394.6 mpy × 10−3 for 25CR and 174.80 mpy × 10−3 for 25SQ, respectively. The highest performance in terms of material losses was found to be 5CR. No significant change in the context of texture geometry was observed in the SEM images. According to quantitative evaluation in electrochemical corrosion tests, the differences are quite close to each other.