TY - JOUR
T1 - Effect of chemistry on martensitic phase transformation kinetics and resulting properties of additively manufactured stainless steel
AU - Wang, Zhuqing
AU - Beese, Allison M.
N1 - Funding Information:
The authors gratefully acknowledge the financial support provided by the National Science Foundation through award number CMMI-1402978. Any opinions, findings, and conclusions or recommendations in the materials are those of the authors and do not necessarily reflect the views of the Nation Science Foundation. We acknowledge Dr. Todd Palmer and Mr. Jay Tressler for component fabrication and Mr. Griffin Jones for the X-ray CT scans at the Center for Innovation Materials Processing through Direct Digital Deposition (CIMP-3D). We acknowledge Dr. Dong Ma and Mr. Matthew Frost of ORNL for neutron diffraction data collection and technical support at the VULCAN beamline. In addition, AMB acknowledges funding from the Oak Ridge Associated Universities Ralph E. Powe Junior Faculty Enhancement Award.
Publisher Copyright:
© 2017 Acta Materialia Inc.
PY - 2017/6/1
Y1 - 2017/6/1
N2 - Here we investigate the effect of chemistry, including initial powder chemistry and spatial chemical variations due to vaporization during fabrication, on strain-induced martensitic phase transformation in 304L stainless steel components fabricated by directed energy deposition (DED) additive manufacturing (AM). The austenite stability was altered by mixing pre-alloyed 304L stainless steel powder with Fe powder, which promoted martensitic phase transformation and resulted in an increase in ultimate tensile strength and elongation to failure over pure 304L walls deposited by DED AM. The chemical composition variation with position, due to spatial variations in thermal history, was quantified, showing that austenite stabilizing elements Cr, Mn, and Ni were preferentially vaporized during deposition. We present a martensitic transformation kinetics equation that describes the evolution of martensite volume fraction with respect to plastic strain as a function of chemistry. This allows for the prediction of strain-induced martensite evolution as a function of strain, nominal chemistry, and heterogeneous chemistry due to vaporization within additively manufactured components.
AB - Here we investigate the effect of chemistry, including initial powder chemistry and spatial chemical variations due to vaporization during fabrication, on strain-induced martensitic phase transformation in 304L stainless steel components fabricated by directed energy deposition (DED) additive manufacturing (AM). The austenite stability was altered by mixing pre-alloyed 304L stainless steel powder with Fe powder, which promoted martensitic phase transformation and resulted in an increase in ultimate tensile strength and elongation to failure over pure 304L walls deposited by DED AM. The chemical composition variation with position, due to spatial variations in thermal history, was quantified, showing that austenite stabilizing elements Cr, Mn, and Ni were preferentially vaporized during deposition. We present a martensitic transformation kinetics equation that describes the evolution of martensite volume fraction with respect to plastic strain as a function of chemistry. This allows for the prediction of strain-induced martensite evolution as a function of strain, nominal chemistry, and heterogeneous chemistry due to vaporization within additively manufactured components.
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U2 - 10.1016/j.actamat.2017.04.022
DO - 10.1016/j.actamat.2017.04.022
M3 - Article
AN - SCOPUS:85017510292
VL - 131
SP - 410
EP - 422
JO - Acta Materialia
JF - Acta Materialia
SN - 1359-6454
ER -