Mitigating Scatter in Mechanical Properties in AISI 410 Fabricated via Arc-Based Additive Manufacturing Process

Area of Science:

• Materials Science
• Manufacturing Engineering
• Metallurgy

Background:

• Wire-based metal additive manufacturing enables large-scale component fabrication, with martensitic steels traditionally used for stamping dies.
• Additive manufacturing's thermal cycles can lead to microstructural inhomogeneity and inconsistent mechanical properties, particularly reduced toughness.

Purpose of the Study:

• To investigate the microstructural heterogeneity and mechanical property scatter in additively manufactured AISI 410 steel.
• To develop post-processing treatments to mitigate these issues and improve material performance for tooling applications.

Main Methods:

• Fabrication of AISI 410 steel samples using robotic gas metal arc welding (GMAW).
• Detailed characterization of microstructure, tensile properties, and Charpy V-notch impact toughness.
• Development and application of post-processing (austenitizing and tempering) treatments.

Main Results:

• Significant scatter observed in tensile properties and impact toughness, correlated with microstructural heterogeneity and delta ferrite formation.
• Post-processing treatments resulted in approximately 70% reduction in tensile data scatter.
• A four-fold improvement in toughness was achieved after post-processing.

Conclusions:

• Microstructural evolution during additive manufacturing directly impacts mechanical property uniformity in martensitic steels.
• Post-processing is effective in enhancing the toughness and consistency of additively manufactured AISI 410 steel.
• Tailoring steel composition for additive manufacturing can lead to printable steels with isotropic and uniform mechanical properties for tooling.