Limits...
Microstructure inhomogeneity of Fe-31%Ni alloy and stabilization of austenite.

Dzevin IM - Nanoscale Res Lett (2015)

Bottom Line: Сrystal structure and mechanism of crystallization of Fe-Ni alloys were studied by methods of X-ray diffraction and metallography.It has been found that macro- and microstructure of austenitic alloy was essentially heterogeneous at the contact and free surfaces and in the volume of a ribbon.The indentified peculiarities of the austenitic phase in different areas of the ribbon are attributed to different cooling rates and the melt crystallization conditions.

View Article: PubMed Central - PubMed

Affiliation: G.V.Kurdyumov Institute of Metal Physics NAS of Ukraine, Vernadsky blvd. 36, Kiev, 03680 Ukraine.

ABSTRACT
Сrystal structure and mechanism of crystallization of Fe-Ni alloys were studied by methods of X-ray diffraction and metallography. It has been found that macro- and microstructure of austenitic alloy was essentially heterogeneous at the contact and free surfaces and in the volume of a ribbon. The indentified peculiarities of the austenitic phase in different areas of the ribbon are attributed to different cooling rates and the melt crystallization conditions.

No MeSH data available.


Related in: MedlinePlus

Amount of martensite vs heating temperature for reverse α–γ transformation. Amount of martensite vs heating temperature for reverse α-γ transformation of quenched Fe-30.6 wt.% Ni-0.05 wt.% C alloy: 1 ribbon, 2 bulk alloy. It should be noted that an interval of α-γ transformation of the ribbon and the bulk alloy shifted to higher temperatures after γ-α-γ cycling. Temperature shift for the ribbon was about 80 K according to X-ray data (Figure 2). After repeated γ-α-γ cycles finish, temperature (Ak) of reverse α-γ transformation remarkably increases (by 75 to 80 K after the 30 cycles of γ-α-γ transformations). Abovementioned results mean that it is necessary to heat a pre-quenched ribbon for each α-γ transformation to higher Ак temperature for the achievement of higher degree of phase hardening by γ-α-γ transformations. It should be noted that overheating of quenched alloy to the temperatures higher than Ак by 1015 K results in development of relaxation processes and to the corresponding decline the phase hardening.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4385281&req=5

Fig3: Amount of martensite vs heating temperature for reverse α–γ transformation. Amount of martensite vs heating temperature for reverse α-γ transformation of quenched Fe-30.6 wt.% Ni-0.05 wt.% C alloy: 1 ribbon, 2 bulk alloy. It should be noted that an interval of α-γ transformation of the ribbon and the bulk alloy shifted to higher temperatures after γ-α-γ cycling. Temperature shift for the ribbon was about 80 K according to X-ray data (Figure 2). After repeated γ-α-γ cycles finish, temperature (Ak) of reverse α-γ transformation remarkably increases (by 75 to 80 K after the 30 cycles of γ-α-γ transformations). Abovementioned results mean that it is necessary to heat a pre-quenched ribbon for each α-γ transformation to higher Ак temperature for the achievement of higher degree of phase hardening by γ-α-γ transformations. It should be noted that overheating of quenched alloy to the temperatures higher than Ак by 1015 K results in development of relaxation processes and to the corresponding decline the phase hardening.

Mentions: It should be noted that an interval of α-γ transformation of the ribbon and the bulk alloy shifted to higher temperatures after γ-α-γ cycling. Temperature shift for the ribbon was about 80 K according to X-ray data (Figure 3). After repeated γ-α-γ cycles finish, temperature (Ak) of reverse α-γ transformation remarkably increases (by 75 to 80 K after the 30 cycles of γ-α-γ transformations). Abovementioned results mean that it is necessary to heat a pre-quenched ribbon for each α-γ transformation to higher Ак temperature for the achievement of higher degree of phase hardening by γ-α-γ transformations. It should be noted that overheating of quenched alloy to the temperatures higher than Ак by 10 to 15 K results in development of relaxation processes and to the corresponding decline the phase hardening.Figure 3


Microstructure inhomogeneity of Fe-31%Ni alloy and stabilization of austenite.

Dzevin IM - Nanoscale Res Lett (2015)

Amount of martensite vs heating temperature for reverse α–γ transformation. Amount of martensite vs heating temperature for reverse α-γ transformation of quenched Fe-30.6 wt.% Ni-0.05 wt.% C alloy: 1 ribbon, 2 bulk alloy. It should be noted that an interval of α-γ transformation of the ribbon and the bulk alloy shifted to higher temperatures after γ-α-γ cycling. Temperature shift for the ribbon was about 80 K according to X-ray data (Figure 2). After repeated γ-α-γ cycles finish, temperature (Ak) of reverse α-γ transformation remarkably increases (by 75 to 80 K after the 30 cycles of γ-α-γ transformations). Abovementioned results mean that it is necessary to heat a pre-quenched ribbon for each α-γ transformation to higher Ак temperature for the achievement of higher degree of phase hardening by γ-α-γ transformations. It should be noted that overheating of quenched alloy to the temperatures higher than Ак by 1015 K results in development of relaxation processes and to the corresponding decline the phase hardening.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385281&req=5

Fig3: Amount of martensite vs heating temperature for reverse α–γ transformation. Amount of martensite vs heating temperature for reverse α-γ transformation of quenched Fe-30.6 wt.% Ni-0.05 wt.% C alloy: 1 ribbon, 2 bulk alloy. It should be noted that an interval of α-γ transformation of the ribbon and the bulk alloy shifted to higher temperatures after γ-α-γ cycling. Temperature shift for the ribbon was about 80 K according to X-ray data (Figure 2). After repeated γ-α-γ cycles finish, temperature (Ak) of reverse α-γ transformation remarkably increases (by 75 to 80 K after the 30 cycles of γ-α-γ transformations). Abovementioned results mean that it is necessary to heat a pre-quenched ribbon for each α-γ transformation to higher Ак temperature for the achievement of higher degree of phase hardening by γ-α-γ transformations. It should be noted that overheating of quenched alloy to the temperatures higher than Ак by 1015 K results in development of relaxation processes and to the corresponding decline the phase hardening.
Mentions: It should be noted that an interval of α-γ transformation of the ribbon and the bulk alloy shifted to higher temperatures after γ-α-γ cycling. Temperature shift for the ribbon was about 80 K according to X-ray data (Figure 3). After repeated γ-α-γ cycles finish, temperature (Ak) of reverse α-γ transformation remarkably increases (by 75 to 80 K after the 30 cycles of γ-α-γ transformations). Abovementioned results mean that it is necessary to heat a pre-quenched ribbon for each α-γ transformation to higher Ак temperature for the achievement of higher degree of phase hardening by γ-α-γ transformations. It should be noted that overheating of quenched alloy to the temperatures higher than Ак by 10 to 15 K results in development of relaxation processes and to the corresponding decline the phase hardening.Figure 3

Bottom Line: Сrystal structure and mechanism of crystallization of Fe-Ni alloys were studied by methods of X-ray diffraction and metallography.It has been found that macro- and microstructure of austenitic alloy was essentially heterogeneous at the contact and free surfaces and in the volume of a ribbon.The indentified peculiarities of the austenitic phase in different areas of the ribbon are attributed to different cooling rates and the melt crystallization conditions.

View Article: PubMed Central - PubMed

Affiliation: G.V.Kurdyumov Institute of Metal Physics NAS of Ukraine, Vernadsky blvd. 36, Kiev, 03680 Ukraine.

ABSTRACT
Сrystal structure and mechanism of crystallization of Fe-Ni alloys were studied by methods of X-ray diffraction and metallography. It has been found that macro- and microstructure of austenitic alloy was essentially heterogeneous at the contact and free surfaces and in the volume of a ribbon. The indentified peculiarities of the austenitic phase in different areas of the ribbon are attributed to different cooling rates and the melt crystallization conditions.

No MeSH data available.


Related in: MedlinePlus