Additively Manufactured Nitrogen-Atomized 17-4 PH Stainless Steel with Mechanical Properties Comparable to Wrought

Abstract

The microstructure of additively manufactured (AM) nitrogen-atomized 17-4 contains 12 ± 4 pct retained austenite after conventional solutionization annealing at 1323 K (1050 °C) resulting in a yield strength of about half that of wrought, which contains ≈ 100 pct BCC/martensite. An AM17-4 microstructure containing a volume fraction of ≈ 95 pct martensite is achieved by solutionizing at 1273 K (1000 °C) instead of 1323 K (1050 °C), where more nitrogen is trapped as M(C,N)-carbides, followed by further cooling to 233 K (− 40 °C). This alternative solutionization recovers the yield strength of the AM material to > 90 pct of its wrought counterpart, a critical first step toward the implementation of AM17-4 in real-world applications.