Speaker
Description
Among different joining methods the electron beam welding is recently applied for manufacturing of turbine components from temperature-resistant nickel-based conventionally cast Alloy 247.
However, the high susceptibility to hot cracking and especially to solidification cracking is a serious obstacle.
Experiments indicate a significant reducing of hot cracking when welding outside the common welding parameter range. To understand these observations, a study of local thermo-mechanical conditions in the samples using numerical simulations was carried out and compared to the experiments. For this purpose, a finite element model for coupled transient thermal and mechanical analysis was created and used. The work presents a comparative analysis of the evolution of strain components in brittle temperature range during cooling, considering the distribution and orientation of the cracks. It could be found various relations between local strain kinetics and crack appearance, with notable influence of the plastic strain vector. Finally, the aspects of assessment of hot crack susceptibility with aid of thermo-mechanical welding simulation are put into discussion.
Keywords: Hot crack susceptibility, Nickel-based alloys, Electron beam welding, Computational welding mechanics, Modeling of welding and joining
| Speaker Country | Deutschland |
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