, Volume 68, Issue 3, pp 869–875 | Cite as

A Metallurgical Evaluation of the Powder-Bed Laser Additive Manufactured 4140 Steel Material

  • Wesley Wang
  • Shawn Kelly


Using laser powder bed fusion (PBF-L) additive manufacturing (AM) process for steel or iron powder has been attempted for decades. This work used a medium carbon steel (AISI 4140) powder to explore the feasibility of AM. The high carbon equivalent of 4140 steel (CEIIW ≈ 0.83) has a strong tendency toward cold cracking. As such, the process parameters must be carefully controlled to ensure the AM build quality. Through an orthogonally designed experimental matrix, a laser-welding procedure was successfully developed to produce 4140 steel AM builds with no welding defects. In addition, the microstructure and micro-cleanliness of the as-welded PBF-L AM builds were also examined. The results showed an ultra-fine martensite lath structure and an ultra-clean internal quality with minimal oxide inclusion distribution. After optimizing the PBF-L AM process parameters, including the laser power and scan speed, the as-welded AM builds yielded an average tensile strength higher than 1482 MPa and an average 33 J Charpy V-notch impact toughness at −18°C. The surface quality, tensile strength, and Charpy V-notch impact toughness of AM builds were comparable to the wrought 4140 steel. The excellent mechanical properties of 4140 steel builds created by the PBF-L AM AM process make industrial production more feasible, which shows great potential for application in the aerospace, automobile, and machinery industries.



The authors would like to thank the Edison Welding Institute (EWI) for funding this project. The authors’ appreciation also extends to Dr. Mahdi Jamshidinia for dedicating his time to organizing the data for this paper, and Ms. Mary Reynolds for the editing work


  1. 1.
    S. Akhtar, C.S. Wright, and M. Youseffi, University of Bradford, Bradford, UK, C. Hauser, T.H.C. Childs, C.M. Taylor, and M. Baddrossamay, University of Leeds, Leeds, West Yorshire, J. Xie, P. Fox, and W. O’Neill, University of Liverpool, UK, UK Solid Freeform Fabrication Proceedings, 656 (2003).Google Scholar
  2. 2.
    S. Akhtar, C.S. Wright, and M. Youseffi, University of Bradford, Bradford, UK, UK Solid Freeform Fabrication Proceedings, 141 (2004).Google Scholar
  3. 3.
    H.J. Niu and I.T.H. Chang, Scr. Mater. 41, 1229 (1999).CrossRefGoogle Scholar
  4. 4.
    H.J. Niu and I.T.H. Chang, Scr. Mater. 41, 25 (1999).CrossRefGoogle Scholar
  5. 5.
    A.N. Chatterjee, S. Kumar, P. Sha, P.K. Mishra, and A.R. Choudhury, Mater. Process. Technol. 136, 151 (2003).CrossRefGoogle Scholar
  6. 6.
    M.A. Taha, A.F. Yousef, K.A. Gany, and H.A. Sabour, Mater.-wiss.u. Werkstofftech, 43, 913 (2012).Google Scholar
  7. 7.
    A. Simchi and H. Pohl, Mater. Eng. A359, 119 (2003).CrossRefGoogle Scholar
  8. 8.
    E. Jelis, M. Clements, S. Kerwien, N.M. Ravindra, and M.R. Hespos, J. Mater. 67, 582 (2015).Google Scholar
  9. 9.
    J.M. Holt, Structural Alloys Handbook (West Lafayette: Cindas Purdue University, 1996), 4140 Steel, pp. 1–27.Google Scholar

Copyright information

© The Minerals, Metals & Materials Society 2016

Authors and Affiliations

  1. 1.Edison Welding InstituteColumbusUSA

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