Metallurgical optimisation of PM superalloy N19

Abstract : Microstructures of the new PM superalloy N19 have been investigated for various heat treatments in order to reach the best compromise between static strength and cyclic resistance. One subsolvus and several supersolvus heat treatments were applied to produce fine (7 µm) and medium (25 µm) grain sizes, respectively. The alloy is shown to be quite sensitive to the cooling conditions after solutioning as the γ' hardening precipitates, both secondary and tertiary, have a direct influence on mechanical properties. Two cooling conditions after solutioning produce a high crack propagation resistance at 650°C with dwell time cycles, which is one of the basic requirements. The low cycle fatigue behaviour appears to be correlated to the grain size, which determines the origin of crack initiation (from ceramic inclusions or not). The other mechanical properties (tensile, creep) remain above target levels. Despite the medium size grain microstructure in the supersolvus condition, a high level of mechanical strength is observed in N19 at elevated temperature. It is understood that further improvement in properties can be achieved by developing coarse grain microstructures.
Document type :
Conference papers
Complete list of metadatas

Cited literature [1 references]  Display  Hide  Download

https://hal-onera.archives-ouvertes.fr/hal-01064956
Contributor : Véronique Soullier <>
Submitted on : Wednesday, September 17, 2014 - 3:12:45 PM
Last modification on : Tuesday, March 26, 2019 - 2:24:03 PM
Long-term archiving on : Thursday, December 18, 2014 - 11:25:30 AM

File

DMSM14014.1404294163.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : hal-01064956, version 1

Citation

Didier Locq, Loic Nazé, Jean-Michel Franchet, Pierre Caron, Alice Dumont, et al.. Metallurgical optimisation of PM superalloy N19. Eurosuperalloys 2014, May 2014, Giens, France. 6 p. ⟨hal-01064956⟩

Share

Metrics

Record views

720

Files downloads

495