About this Abstract |
| Meeting |
2025 AWS Professional Program
|
| Symposium
|
2025 AWS Professional Program
|
| Presentation Title |
Development of a GleebleTM--Based Test for Evaluation of DDC in Austenitic Alloys |
| Author(s) |
John Welsh, Anil Singh, Boian Alexandrov, Michael Mills |
| On-Site Speaker (Planned) |
John Welsh |
| Abstract Scope |
Ductility dip cracking (DDC) is a solid-state failure mechanism experienced in highly restrained multipass welds of austenitic alloys. A new approach for studying the effect of welding thermo-mechanical histories on DDC was recently developed and validated. It is based on quantifying welding process imposed mechanical energy (IME), which is calculated as a cumulative integral of multiple reheat stress-strain histories experienced in the weld metal. It was hypothesized that evolution of DDC can be attributed to IME in different temperature ranges. IME in the DDC temperature range (IMECT), 800-1050 °C, leads to void nucleation. IME in the low temperature range (IMELT), below 800 °C, leads to void growth and coalescence in DDC. IME in the recrystallization temperature range (IMERT), which is from 1050 °C to the solidus temperature, mitigates DDC through dynamic recrystallization (DRX). The local IME distribution in the weld metal is quantified using finite element analysis (FEA) models of the welding process.
A DDC susceptibility evaluation test which utilizes the IME approach has been developed at OSU. It replicates thermal histories experienced in highly restrained multipass welds via GleebleTM simulations. Thermal histories of weld locations that experience DDC and of DDC-free locations, which undergo extensive DRX, are extracted from FEA models and simulated over fully restrained GleebleTM specimens. The DDC and DRX response is quantified by metallurgical characterization and corelated to IMECT and IMERT values generated by the Gleeble simulations. DDC susceptibility is ranked by IMECT values needed to generate cracking and IMERT value that mitigates DDC. The test is demonstrated via replicating thermo-mechanical histories in a highly restrained narrow groove weld of FM-52i which contained DDC and DDC-free areas with extensive DRX. |
| Proceedings Inclusion? |
Undecided |