Effect of heat treatments on microstructural evolution of additively manufactured and wrought 17-4PH stainless steel. (15th October 2018)

• Record Type: Journal Article
• Authors: Sun, Yu; Hebert, Rainer J.; Aindow, Mark
• Is Part Of: Materials & design. Volume 156(2018)
• Page Start: 429
• Page End: 440
• Publication Date: 2018-10-15
• Subjects: 17-4PH stainless steel -- Selective laser melting -- Heat treatment -- EBSD -- TEM; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2018.07.015
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Additively manufactured (AM) components usually have nonequilibrium microstructures. Post-built heat treatments are recommended for AM components to achieve homogenous microstructures. In this study, the effects were investigated of conventional solutionizing and precipitation hardening (H-900) heat treatments on the microstructure evolution of 17-4PH AM and wrought components. Microstructural characterization techniques including SEM, TEM and EBSD analysis were used on 17-4PH AM and wrought components to obtain quantitative information about the microstructure and phase evolution during these heat treatments. These microstructural studies demonstrate that 17-4PH AM components can achieve microstructures and hardnesses similar to those of wrought samples by post-built heat treatments. Graphical abstract: Highlights: As-built 17-4 PH has steel an inhomogeneous columnar microstructure composed of ferrite, martensite, and some austenite. Solution heat treatments homogenized the grain structure and eliminated the {100} texture observed in as-built samples. Oxide inclusions pinned grain boundaries during heat treatment thereby refining the grain structure. Precipitation heat treatment yielded Cu-rich nano-precipitates without further changes in the grain structure. Heat treatments can achieve comparable microstructures and hardness in additively manufactured and wrought 17-4 PH samples.