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

Abstract

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.