Effect of solution treatments on the FCC/HCP isothermal martensitic transformation in Co-27Cr-5Mo-0.05C aged at 800°C

The effects of tensile deformation on the amount of hcp phase formed during a 3 hour isothermal aging at 800 °C is studied using in-situ X-ray diffraction and scanning electron microscopy. It is shown that the start of the isothermal martensitic transformation during aging of this material is delayed by prior plastic deformation. Nevertheless, the total amount of hcp phase present in the microstructure at the beginning of aging increases at a continuously decreasing rate due to stress-assisted transformation. This behavior is attributed to the relieving of internal stresses produced by plastic deformation prior to aging. Finally, during the last stage of aging, the amount of hcp phase in the microstructure increases as a result of isothermal martensitic transformation. It is suggested that the presence of mechanically-induced hcp phase during aging inhibits the thermally activated nucleation process that leads to the isothermal martensitic transformation.

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On the Isothermal Martensitic Transformation in 3Y-TZP

Journal of the American Ceramic Society ◽

10.1111/j.1151-2916.1993.tb05330.x ◽

1993 ◽

Vol 76 (4) ◽

pp. 1025-1030 ◽

Cited By ~ 29

Author(s):

Gesa Behrens ◽

Gerd W. Dransmann ◽

Arthur H. Heuer

Keyword(s):

Martensitic Transformation ◽

Isothermal Martensitic Transformation

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HVEM in situ Observation of Isothermal Martensitic Transformation under Applied Stress

Transactions of the Japan Institute of Metals ◽

10.2320/matertrans1960.26.861 ◽

1985 ◽

Vol 26 (12) ◽

pp. 861-868 ◽

Cited By ~ 8

Author(s):

T. Kikuchi ◽

S. Kajiwara

Keyword(s):

Martensitic Transformation ◽

Applied Stress ◽

Isothermal Martensitic Transformation

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Erratum an isothermal martensitic transformation in a quenched Au-49.5at%Cd alloy

Scripta Materialia ◽

10.1016/s1359-6462(99)00005-6 ◽

1999 ◽

Vol 40 (7) ◽

pp. 879

Author(s):

M Kozuma ◽

Y Murakami ◽

T Kawano ◽

K Otsuka

Keyword(s):

Martensitic Transformation ◽

Isothermal Martensitic Transformation

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The strain variation during the isothermal B2→B19’ martensitic transformation in the quenched or annealed Ni51Ti49 alloy

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1213/1/012005 ◽

2022 ◽

Vol 1213 (1) ◽

pp. 012005

Author(s):

A Ivanov ◽

A Gabrielian ◽

S Belyaev ◽

N Resnina ◽

V Andreev

Keyword(s):

Martensitic Transformation ◽

Volume Fraction ◽

Isothermal Holding ◽

Isothermal Transformation ◽

Annealed Sample ◽

Strain Variation ◽

Maximum Value ◽

Niti Phase ◽

Alloy Heat ◽

Isothermal Martensitic Transformation

Abstract The strain variation during the isothermal holding under constant stress was studied in the quenched or annealed Ni51Ti49 alloy samples. The isothermal strain variation was found in both samples and this strain was completely recovered on subsequent unloading and heating. This allowed to conclude that the strain variation on holding was caused by the isothermal martensitic transformation. It was found that the maximum value of isothermal strain depended on the alloy heat treatment. This value was equal to 0.5 % in annealed sample and it was equal to 6 % in quenched sample. It was assumed that the formation of the Ni4Ti3 phase during annealing led to a decrease in concentration of substitutional Ni atoms in NiTi phase that were responsible for the isothermal transformation. As a result, the less volume fraction of the martensite formed during holding that supresses the strain variation in annealed samples.

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