Manipulating Martensitic Transformation and Residual Stress Development in Stress Superposed Incremental Forming of SS304

Published

May 1, 2025

Author(s)

Elizabeth Mamros, Fabian MaaB, Thomas Gnaupel-Herold, A. E. Tekkaya, Brad L. Kinsey, Jinjin Ha

Abstract

Stress superposition is one of the strategies used in metal deformation processes to increase the material formability, decrease the required forming forces, and create highly customized components. To investigate the effects of tensile and compressive stresses superposed to the single point incremental forming (SPIF) process, experiments and numerical simulations were conducted for a stainless steel 304 (SS304) truncated square pyramid geometry. Tensile stresses were superposed in-plane on the specimen blank by a custom hydraulic frame, and compressive stresses were incorporated via a polyurethane die. Identified parameters for the Beese and Mohr 2011 martensitic transformation kinetics model for SS304 were used in a two-step finite element approach to predict the '-martensite volume fraction. These results were compared to experimental results measured by a Feritscope at four locations along each pyramid wall and validated by electron backscatter diffraction. The residual stresses were measured using x-ray diffraction. The parts from each incremental forming process revealed differences in the residual stresses, which impacted the final geometries, and the '-martensite volume fraction at the four measurement locations. The evolution of the stress state, defined by the stress triaxiality and Lode angle parameter, for each process contributed to the phase transformation variance. Based on these results, stress-superposed incremental forming can be implemented to manipulate the final part properties, which is ideal for applications requiring highly customized parts, e.g., biomedical trauma fixation hardware.

Citation

Advances in Industrial and Manufacturing Engineering

Volume

10

Pub Type

Journals

Download Paper

https://doi.org/10.1016/j.aime.2025.100161

Local Download

Keywords

Stainless steel, stress superposition, incremental forming, martensite, phase transformation, residual stresses

Citation

Mamros, E. , MaaB, F. , Gnaupel-Herold, T. , Tekkaya, A. , Kinsey, B. and Ha, J. (2025), Manipulating Martensitic Transformation and Residual Stress Development in Stress Superposed Incremental Forming of SS304, Advances in Industrial and Manufacturing Engineering, [online], https://doi.org/10.1016/j.aime.2025.100161, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958651 (Accessed July 22, 2025)