Selective laser melted stainless steel CX: Role of built orientation on microstructure and micro-mechanical properties

Abstract

In this work, the effect of built direction on the small-scale mechanical properties and microstructure of a novel maraging stainless steel (SS-CX) manufactured through the selective laser melting (SLM) process was studied. Advanced electron microscopy and nanoindentation techniques were utilized to evaluate retained austenite fraction and micro-mechanical properties, respectively. Different thermal histories caused by the change of the built direction resulted in microstructures with different volume fractions of retained austenite and grain morphology. Furthermore, the slower cooling rates in the vertically built sample was found to result in the formation of large elongated grains and lower hardness values during the nanoindentation experiments.