About this Abstract |
| Meeting |
2025 AWS Professional Program
|
| Symposium
|
2025 AWS Professional Program
|
| Presentation Title |
Microalloying Effects on Grain Size in the CGHAZ of TMP Steels |
| Author(s) |
Sawyer Gill, Jonah Klemm-Toole, Kip O. Findley, Gregory Lehnhoff |
| On-Site Speaker (Planned) |
Sawyer Gill |
| Abstract Scope |
Toughness in the heat affected zone (HAZ) of welds in structural steels is of the utmost importance for fracture critical applications. In particular, maintaining high toughness in the coarse grain heat affected zone (CGHAZ) is of interest in structural and linepipe steel applications. One of the microstructural features that strongly influences toughness in the CGHAZ is the prior austenite grain size (PAGS) that develops during thermal cycles in the heat affected zone. Microalloying additions are often made to base metal chemistries to result in the desired microstructure and properties after thermomechanical processing (TMP), but different alloying strategies might be needed to control austenite grain growth in the CGHAZ. In this work, a systematic variation of microalloying additions were evaluated to determine their influence on PAGS in the CGHAZ of gas metal arc welds (GMAW). A series of TMP microalloy steels containing variable Nb, V, and Mo content were subjected to GMAW with heat inputs from 9.4 – 107 kJ/in to evaluate the degree of austenite grain size control over a wide range of heat inputs. The HAZ regions of the welds were etched to reveal the PAGS, and the results are compared against model predictions of non-isothermal grain growth accounting for microalloy precipitates that coarsen and/or dissolve during the HAZ thermal cycle. The results of this work are expected to highlight microalloying strategies that can be used to produce fine PAGS in the CGHAZ of structural steels thus achieving the high toughness requires for demanding structural applications. |
| Proceedings Inclusion? |
Undecided |