Laser Spot Welding of Additive Manufactured 304L Stainless Steel

Published

February 1, 2022

Author(s)

Brian Simonds, Cheryl Hawk, Stephen Liu, Daniel Javernick, Robin Pacheco, Michael Brand, Jack R. Tanner, Greg Vigil

Abstract

The goal of this work is to understand if an additively manufactured 304L stainless steel exhibited similar spot welding behavior as wrought 304L stainless steel. Due to the many differences between an additively manufactured component and wrought product, it is important to determine how the material interacts with the laser and how it would affect the weld bead morphology. In this paper, the laser coupling efficiency, weld size and solidification of spot welds produced in wrought and additively manufactured 304L stainless steel were investigated. The coupling efficiency of wrought and additively manufactured 304L stainless steel of the same surface condition were about the same over a range of applied laser energies. However, laser welding of the untreated (rougher) surface of additively manufactured 304L showed improved coupling efficiency ranging between 3.3% and 100%. The rougher surface traps the reflected light allowing for multiple reflections to occur at lower laser energies. The resulting spot weld microstructures differed from welds made in wrought 304L and additively manufactured 304L. Welds made in wrought 304L were fully austenitic containing what is suspected to be massive austenite, which suggests that these welds solidified as primary ferrite. Welds made in additively manufactured 304L were also fully austenitic and contained both cellular austenite and what is suspected to be massive austenite. These observations mean that welds made in additively manufactured 304L solidified as primary ferrite and primary austenite. The differences in weld microstructures made in wrought and AM 304L can be attributed to differences in the composition and solidification rate.

Citation

Welding Journal

Pub Type

Journals

Keywords

Laser Welding, Stainless Steel, Additive Manufacturing

Citation

Simonds, B. , Hawk, C. , Liu, S. , Javernick, D. , Pacheco, R. , Brand, M. , Tanner, J. and Vigil, G. (2022), Laser Spot Welding of Additive Manufactured 304L Stainless Steel, Welding Journal (Accessed March 15, 2025)