About this Abstract |
| Meeting |
2025 AWS Professional Program
|
| Symposium
|
2025 AWS Professional Program
|
| Presentation Title |
Effect of Ni on Charpy Impact Toughness of Low Ti, C-Mn-Ni Multi-Pass Steel Weld Metal |
| Author(s) |
Jesse Porter, Carolin Fink, Glyn Evans |
| On-Site Speaker (Planned) |
Jesse Porter |
| Abstract Scope |
This study investigates the effect of nickel (Ni) content on the microstructural evolution and toughness behavior of low Ti, C-Mn-Ni steel multi-pass weld metal, with a particular focus on notch location and the stability of acicular ferrite (AF) under thermal cycling. Multi-pass welds were produced using shielded metal arc welding with controlled variations in manganese (0.6 wt.% and 1.4 wt.%) and titanium (5 ppm and 30 ppm) content, along with varying Ni levels (0.03% wt.% through 3.1wt.%). Charpy V-notch (CVN) impact testing at multiple temperatures revealed that the notch location’s microstructure distribution within the multi-pass weld metal influenced toughness. In the as-welded condition of the top bead, welds containing .6% Mn and 30 ppm Ti, combined with higher nickel content, developed a high fraction of AF. Notably in the notch location, even after subsequent thermal cycles from additional weld passes—where the AF fraction was significantly reduced or removed—these high-Ni samples demonstrated the highest impact toughness as compared to lower-Ni content welds. This behavior suggests that the initial presence of AF may impart a refined microstructural framework or favorable transformation behavior that persists despite its eventual disappearance. Ongoing electron microscopy characterization is focused on further investigating the presence of AF and its influence on the microstructure following additional thermal cycles. Additionally, the role of Mn and Ti content will be examined to assess their effect on the stability of beneficial microstructures during reheating. These findings will offer valuable insights for optimizing Mn-Ni-Ti in steel compositions to ensure consistent toughness in multi-pass welded structures. |
| Proceedings Inclusion? |
Undecided |