Influence of scanning strategies on microstructure, residual stress, and corrosion behavior of 17-4 PH stainless steel fabricated by selective laser melting

• Published in: Proceedings of the Institution of Mechanical Engineers. Part E, Journal of process mechanical engineering Journal of process mechanical engineering, 2023-06, Vol.237 (3), p.690-701
• Main Authors: Kartikeya Sarma, I., Selvaraj, N., Kumar, Adepu
• Format: Article
• Language: English
• Subjects: Austenite; Casting alloys; Corrosion; Corrosion resistance; Corrosion resistant steels; Crystal defects; Density; Electron backscatter diffraction; Grain size; Laser beam melting; Martensitic stainless steels; Microstructure; Precipitation hardening steels; Residual stress; Scanning; Stainless steel
• ISSN: 0954-4089; 2041-3009
• DOI: 10.1177/09544089221106263

In the present study, the effect of hexagonal (inside out and outside in), rectangular (horizontal, vertical, alternate, and both), and strip (horizontal, vertical, alternate, and both) scan strategies on the microstructure, residual stresses, and the corrosion behavior of 17-4 PH stainless steel samples fabricated by selective laser melting were investigated. The results indicate that through hexagonal inside-out scanning strategy, the sample density and hardness are double than that of wrought and cast alloys. Microstructure consists of small and large molten pools on the side and front surface of each sample generated using a different scan strategy. Austenite phase and ferrite peak at the highest intensity were observed by X-ray diffraction for hexagonal inside-out sample. Electron back scattered diffraction (EBSD) orientation maps showed a high-density of ɣ-austenite phase (43%) in the finer grain size area of the hexagonal inside-out scan strategy sample. Low residual stresses and high corrosion resistance (