Gas Atomization of Duplex Stainless Steel Powder for Laser Powder Bed Fusion

Area of Science:

• Materials Science
• Metallurgy
• Additive Manufacturing

Background:

• Duplex stainless steel powders are crucial for additive manufacturing applications.
• Limited research exists on developing super duplex stainless steel powders for laser additive manufacturing.

Purpose of the Study:

• To investigate the effects of atomization gas (argon vs. nitrogen) and temperature on super duplex stainless steel powder characteristics.
• To evaluate the processability of these powders using laser powder bed fusion (PBF-LB/M).

Main Methods:

• Atomization of X2CrNiMoCuWN25-7-4 (AISI F55) super duplex stainless steel using argon or nitrogen at varying temperatures.
• Characterization of powder properties, including nitrogen content and internal porosity.
• Assessment of powder processability via PBF-LB/M.

Main Results:

• Nitrogen gas in the melting chamber increased nitrogen dissolution and content in powders.
• Argon-atomized powders exhibited higher internal gas porosity compared to nitrogen-atomized powders.
• Higher atomization gas temperatures yielded finer powder particles.
• The developed duplex stainless steel powders demonstrated good processability in PBF-LB/M.

Conclusions:

• Gas chemistry and content within powder particles had a negligible impact on the porosity of as-built PBF-LB/M parts.
• Optimized atomization parameters are key for producing high-quality duplex stainless steel powders for additive manufacturing.