Physical-mechanical and electrochemical corrosion behaviors of additively manufactured Cr-Ni-based stainless steel formed by laser cladding

摘要

The physical-mechanical and electrochemical corrosion behaviors of additively manufactured Cr-Ni-based stainless steel were investigated. Microstructural characterizations of the claddings were tested utilizing EDS, XRD, SEM instruments. Microhardness and nano-indentation measurements were executed to evaluate the mechanical properties. Electrochemical corrosion behaviors of the claddings were evaluated in 10 wt.% NaCl solution, compared with AISI 1045 and 304L steels. The claddings showed the main peaks corresponding to the alpha-Fe and substitutional solid solution phases. The dendritic austenite and interdendritic ferrite phases grew up under the high solidification and cooling rate. The porosity level of 0.48% in area per cent with a mean pore size of 0.04 mu m was measured due to high energy delivered by the laser beam and good wettability of the powders. Microhardness of the claddings was found to be 550 HV0.05, indicating higher value compared to the substrate (250 HV0.05). Besides, material constitutive model was proposed by a power law description based on the reverse algorithm. The high yield strength reflected a difficult-to-cut potential in the subsequent cutting process. Moreover, the cladding provided the best corrosion resistance, followed by AISI 304L stainless steel, and AISI 1045 steel the worst. Pitting corrosion was prone to occur in enriched chloride environments. (C) 2016 Elsevier Ltd. All rights reserved.