Controlling Phase Composition in Selective Laser Melted Stainless Steels
Abstract
Commercially important stainless steels can be austenitic or martensitic and this phase
composition fundamentally controls the mechanical properties of the material. With selective
laser melting (SLM), 17-4 stainless steel can be produced in either phase depending on powder
composition, SLM conditions and post-build heat treatment. This behavior is examined using
optical and electron microscopy and high temperature x-ray diffraction in order to better
understand the formation of metastable austenite and its transformation to martensite. Control of
phase composition can produce a material with either extremely large strain-to-failure or high
yield strength and can provide a method for completely eliminating residual stress.