Search

This investigation concerns the application of the profilometry‐based indentation plastometry (PIP) methodology to obtain stress–strain relationships for material in the vicinity of fusion welds. These are produced by The Welding Institute (TWI), using submerged arc welding to join pairs of thick steel plates. The width of the welds varies from about 5 mm at the bottom to about 40–50 mm at the top. For one weld, the properties of parent and weld metal are similar, while for the other, the weld metal is significantly harder than the parent. Both weldments are shown to be approximately isotropic in terms of mechanical response, while there is a small degree of anisotropy in the parent metal (with the through‐thickness direction being slightly softer than the in‐plane directions). The PIP procedure has a high sensitivity for detecting such anisotropy. It is also shown that there is excellent agreement between stress–strain curves obtained using PIP and via conventional uniaxial testing (tensile and compressive). Finally, the PIP methodology is used to explore properties in the transition regime between weld and parent, with a lateral resolution of the order of 1–2 mm. This reveals variations on a scale that would be very difficult to examine using conventional testing.

© 2021 Acta Materialia Inc. This investigation concerns superalloy samples produced by an additive manufacturing procedure. Microstructural examination confirmed that they exhibited a columnar grain structure, with the grains elongated in the growth (“build”) direction and exhibiting a strong texture involving alignment of 〈100〉 parallel to this axis. Samples were tensile tested along both build and transverse directions, being found to be both stiffer and harder in the latter. This material thus exhibits well-characterized anisotropy, making it well-suited to study of how this affects outcomes from an indentation-based procedure for obtaining stress-strain curves. This is termed Profilometry-based Inverse FEM for Plasticity Parameters from Indentation (PIP). True stress-strain curves obtained using this methodology were found to be entirely consistent with the directly-measured curves. Furthermore, it is shown that full 3-D characterization of the indent profiles can be used to obtain at least a semi-quantitative indication of the nature and strength of the plastic anisotropy. This constitutes a significant advance in the context of a technique that could have a transformative effect on mechanical testing procedures.