Impact of Heat Treatments on Residual Stress in Additively Manufactured AISI H13 Tool Steel

Author(s)

Conde, Fabio Faria ; Fonseca, Eduardo B. ; Freire, Suyanny A. ; Lopes, Eder S. N.

• Document type: Journal article
• Source: Journal of Materials Engineering and Performance; v. N/A, p. 11-pg., 2025-06-11.

Abstract

Additive manufacturing (AM), or 3D printing, enables the fabrication of complex and customized components directly from digital models. Despite its advantages, a major challenge is the generation of residual stresses due to the unique thermal cycles in AM processes. These stresses, caused by layer-by-layer material deposition with uneven heating and cooling, can affect the mechanical performance and reliability of parts-potentially leading to distortion, cracking, or failure. In this study, the formation and evaluation of residual stresses in AISI H13 tool steel processed by powder bed fusion with laser beam (PBF-LB) were investigated. The samples were manufactured using a Yb:YAG fiber laser with an 80 mu m spot size, 172 W power, and 700 mm/s scan speed. Post-processing included quenching followed by either single or double tempering, at temperatures of 650 degrees C and 550 degrees C. Thermodynamic simulations were performed to predict phase formation and physical properties, aiming to assess the impact of phase transformation on volumetric changes and, consequently, on residual stress development. Microstructural analysis and hardness tests were conducted, revealing that double-tempered samples at 550 degrees C exhibited the highest hardness, reaching 665 HV. A recently developed x-ray diffraction method was used to evaluate residual stresses by analyzing 2-theta peak shifts with a 2D detector, allowing for the estimation of lattice parameter changes. Residual stress results were correlated with microstructural features and hardness values. Compressive residual stresses were associated with the formation of fresh martensite from retained austenite and carbide precipitation. Additionally, hardness was strongly correlated with full width at half maximum (FWHM) variation, indicating microstructural refinement. This integrated approach provides valuable insights into the control and prediction of residual stresses in AM components, contributing to the optimization of processing parameters and post-treatment strategies. (AU)

• FAPESP's process: 24/02502-8 - Optimization study of microstructural and mechanical properties of AISI-H13 tool steel samples processed by additive manufacture with programmable laser beam
• Grantee: Suyanny Assunção Freire
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 24/14945-1 - Mitigation of retained austenite by compositional modification of AISI H13 tool steel processed by powder bed fusion
• Grantee: Fábio Faria Conde
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors
• FAPESP's process: 24/02060-5 - Mitigation of retained austenite by compositional modification of AISI H13 tool steel processed by powder bed fusion
• Grantee: Éder Sócrates Najar Lopes
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/06045-0 - Advanced manufacturing: exploration of methods for control and validation of powder bed fusion process in additive manufacturing process
• Grantee: Éder Sócrates Najar Lopes
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 19/06276-4 - Study of processability and post-processing of AISI H13 tool steel by powder bed fusion: micro/nanostructural and mechanical characterization
• Grantee: Eduardo Bertoni da Fonseca
• Support Opportunities: Scholarships in Brazil - Doctorate