Influence of Selective Laser Melting Process and Heat Treatment Parameters on the Corrosion Resistance of 17-4 Precipitation Hardening Stainless Steel

Selective laser melting (SLM) is an advanced additive manufacturing technique that enables the fabrication of complex metal components with high precision. However, inadequate parameter optimization can lead to defects that compromise the corrosion resistance of fabricated parts. Therefore, optimizing both SLM and heat treatment parameters is essential for enhancing electrochemical properties. The present work aims to determine the effect of the SLM process and heat treatment parameters on the corrosion resistance of SLM-made 17-4 PH stainless steel. A set of SLM and heat treatment parameters (laser power, scanning speed, aging time, and aging temperature) was determined by employed Taguchi method and a set of cyclic potentiodynamic polarization and electrochemical impedance experiments was performed in 3.5 wt% NaCl solution to generate corrosion data. The Taguchi method and statistical analysis of variance reveal the effect of laser power, scanning speed, aging time, and aging temperature on corrosion current density and passive film resistance of the SLM-made 17-4 PH samples. Laser power and aging temperature had the most significant effects, with lower laser power and higher aging temperature leading to decreased corrosion resistance, as indicated by higher corrosion current density and lower passive film resistance. Additionally, this study proposes empirical predictive models to estimate the electrochemical properties of SLM-made 17-4 PH stainless steel.