Cracking during High-Temperature Deformation of a High-Strength Polycrystalline CoNi-Base Superalloy

Hausmann D, Freund L, Solis C, Giese S, Göken M, Gilles R, Neumeier S (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Metals MDPI

Book Volume: 12

Journal Issue: 9

DOI: 10.3390/met12091520

Abstract

The crack susceptibility during processing has a crucial influence on the workability of wrought alloys. In particular, the processing of high-strength alloys that are prone to cracking is challenging and various process parameters have to be optimized to achieve a good formability. The polycrystalline CoNi-base superalloy CoWAlloy1 provides a high potential for high-temperature applications due to it having a large forging window, a high gamma ' fraction and excellent creep properties. In order to study its formability during hot rolling, its deformation behavior and susceptibility to cracking were characterized by sub- and supersolvus compression tests at temperatures between 1000-1150 degrees C. At temperatures around the gamma ' solvus temperature, no cracks formed during the compression testing, while at lower temperatures, cracking occurred. Additionally, an in-situ high-temperature small-angle neutron scattering revealed the phase fractions and the precipitate size distributions at different processing temperatures. It was found that a high fraction of gamma ' forms during cooling and cracking starts at the surface of the bar, when the hot bar encounters the cold rolls during hot rolling. Apparently, the precipitation of gamma ', which causes a high strength and reduced ductility, and the absent recrystallization leads to pronounced crack propagation and limited formability below the gamma ' solvus temperature.

Authors with CRIS profile

Daniel Hausmann Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Lisa Freund Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Sven Giese Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Mathias Göken Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Steffen Neumeier Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Involved external institutions

Helmholtz-Zentrum Geesthacht Zentrum für Material- und Küstenforschung GmbH (HZG) DE Germany (DE) Technische Universität München (TUM) DE Germany (DE)

How to cite

APA:

Hausmann, D., Freund, L., Solis, C., Giese, S., Göken, M., Gilles, R., & Neumeier, S. (2022). Cracking during High-Temperature Deformation of a High-Strength Polycrystalline CoNi-Base Superalloy. Metals, 12(9). https://doi.org/10.3390/met12091520

MLA:

Hausmann, Daniel, et al. "Cracking during High-Temperature Deformation of a High-Strength Polycrystalline CoNi-Base Superalloy." Metals 12.9 (2022).

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