Induction Butt Welding Followed by Abnormal Grain Growth: A Promising Route for Joining of Fe–Mn–Al–Ni Tubes

• Published in: Shape memory and superelasticity : advances in science and technology Vol. 6; no. 1; pp. 131 - 138
• Main Authors: Vollmer, M., Baunack, D., Janoschka, D., Niendorf, T.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.03.2020; Springer Nature B.V
• Subjects: Butt welding; Characterization and Evaluation of Materials; Chemistry and Materials Science; Grain growth; Heat affected zone; Heat treating; Heat treatment; Iron; Joining; Manganese; Materials Science; Microstructure; Nickel; Process parameters; Shape memory alloys; Smst2019; Thermal cycling; Tubes; Reset of microstructure; Geometry independent single crystals; Complex geometry; Iron-based shape memory alloys
• ISSN: 2199-384X; 2199-3858
• DOI: 10.1007/s40830-019-00261-2

The present study focuses on induction butt welding of Fe–Mn–Al–Ni tubes. By comparing different processing routes, characterized by different temperatures and forces during welding, it was possible to find adequate process parameters for realization of defect-free joints. Moreover, it was feasible to fully reset the microstructure prevailing in the heat-affected zone by a subsequent cyclic heat treatment promoting abnormal grain growth. Tensile testing up to a maximum strain of 6% revealed excellent pseudoelastic properties of the final microstructural condition. The present study shows for the first time that welding with superimposed pressure is well suited for joining of Fe–Mn–Al–Ni shape memory alloys. Furthermore, it is revealed that abnormal grain growth induced by a cyclic heat treatment can be applied independently of the geometry of the component.