Evaluating the Corrosion Performance of Wrought and Additively Manufactured (AM) Invar ® and 17-4PH

A Renishaw AM 400 was used to produce Laser Powder Bed fusion (LPBF) iron alloy Invar ® and 17-4PH components. Build parameters were systematically changed and the corrosion performance of the samples produced was investigated using a combination of scanning vibrating electrode technique (SVET) and advanced conventional electrochemical techniques. The results indicated that small changes in the density of the LPBF parts due to porosity resulted in large changes to the materials corrosion susceptibility. The LPBF samples also demonstrated significantly more variation in pitting potential measurements compared to wrought samples indicating inhomogeneity in the built parts. References to AM samples in this work refer to samples produced using LPBF.