Influence of homogenisation treatments on the hot ductility of cast ATI® 718Plus®: Effect of niobium and minor elements on liquation characteristics
Journal article, 2020

The hot ductility of cast ATI® 718Plus® was assessed using the Gleeble thermo-mechanical simulator after being subjected to different homogenisation heat treatments. The hot ductility deteriorated significantly after long-dwell homogenisation heat treatments for 24 h at temperatures of 1120 and 1190 °C as compared with those treated at a short dwell time of 4 h at the same temperatures. The observed ductility deterioration was related to more extensive liquation along the grain boundaries caused by different mechanisms, e.g., liquation by solute segregation mechanism, Laves melting, constitutional liquation of MC carbides and supersolidus grain boundary melting, with the effect and extent depending on the solute changes after the homogenisation heat treatments. Furthermore, the role of Nb as the solute element and as the precipitate former, as well as the effect of minor alloying elements segregating along the grain boundaries, is discussed in connection to grain boundary liquation, which contributes to a better understanding of heat-affected zone liquation cracking susceptibility of cast ATI® 718Plus®.

Segregation

Diffusion

Boron

HAZ Cracking

Constitutional liquation of carbides

Niobium

Author

Sukhdeep Singh

Chalmers, Industrial and Materials Science, Materials and manufacture

Fabian Hanning

Chalmers, Industrial and Materials Science, Materials and manufacture

Joel Håkan Andersson

Chalmers, Industrial and Materials Science, Materials and manufacture

Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

0921-5093 (ISSN)

Vol. 799 140151

Subject Categories

Metallurgy and Metallic Materials

Areas of Advance

Materials Science

DOI

10.1016/j.msea.2020.140151

More information

Created

9/15/2020