Effect of Magnetic Field on Isothermal Martensitic Transformation in SUS304L Stainless Steel

2007 ◽  
Vol 561-565 ◽  
pp. 2333-2336 ◽  
Author(s):  
Jae Hwa Lee ◽  
Takashi Fukuda ◽  
Tomoyuki Kakeshita
Keyword(s):  
Magnetic Field ◽  
Stainless Steel ◽  
Martensitic Transformation ◽  
Isothermal Holding ◽  
Holding Time ◽  
Solution Treated ◽  
Α Phase ◽  
Fcc Phase ◽  
Isothermal Martensitic Transformation

We have found that solution-treated or sensitized SUS304L stainless steel transforms isothermally from the γ (fcc)-phase to the α' (bcc) martensite via the ε' (hcp) martensite, that is, the amount of the α'-phase increases with increasing holding time. By applying magnetic field, the α' martensite can be induced in the ε'-plate when the steel has a sufficiently large ε' plate formed beforehand by isothermal holding. However, the α' martensite cannot be induced by magnetic field in the ε'-plate formed beforehand by a deformation-induced transformation.

scholarly journals Evaluation of the Aging Effect on the Microstructure of Co-28Cr-6Mo-0.3C Alloy: Experimental Characterization and Computational Thermodynamics

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 581 ◽  
Author(s):  
Shahab Zangeneh ◽  
Ersoy Erisir ◽  
Mahmoud Abbasi ◽  
Ali Ramazani
Keyword(s):  
Martensitic Transformation ◽  
Solution Treatment ◽  
Aging Effect ◽  
Sample Solution ◽  
Solution Temperature ◽  
Solution Treated ◽  
The Matrix ◽  
Fcc Phase ◽  
Experimental Findings ◽  
Lamellar Type

In the current research, we studied the role of the solution treatment and aging on the microstructure of a Co–28Cr–5Mo–0.3C alloy. We used metallographic observations, scanning electron microscopy (SEM), and hardness measurements for the evaluations. We also made a comparison between the phase equilibrium calculated with Thermo-Calc, using TCFE8 and TCNI8 thermodynamic databases and experimental findings. The experimental results showed that the transformation of the metastable FCC phase to the HCP phase during aging was extremely sensitive to the solution treatment prior to aging. The effect of the increase in the solution temperature and time was detectable through promotion of the martensitic transformation during quenching in which HCP1 (straight bands) and HCP2 (lamellar-type constitution) phases had developed. In contrast, a low solution temperature and time caused most of the primary carbides to remain in an undissolved condition in the matrix; therefore, during aging, no sign of the FCC to HCP1 (straight bands) phase transformation could be observed. However, we observed the formation of the HCP2 phase (lamellar-type constitution) at the grain boundaries. In addition, the X-ray diffraction pattern indicated that the sample solution treated at lower temperatures and shorter times had a stronger martensitic transformation during aging compared to the sample solution treated at higher temperatures and longer times. Hardness measurements confirmed the results. Thermodynamical calculations showed that an agreement existed between the experiments and calculations. We also discuss the results from the TCFE8 and TCNI8 databases.

Isothermal Martensitic Transformation in a Sensitized SUS304 Stainless Steel under Magnetic Field

2010 ◽  
Vol 654-656 ◽  
pp. 130-133 ◽  
Author(s):  
Ju Young Choi ◽  
Takashi Fukuda ◽  
Tomoyuki Kakeshita
Keyword(s):  
Magnetic Field ◽  
Stainless Steel ◽  
Incubation Time ◽  
Isothermal Holding ◽  
Solution Treatment ◽  
Austenitic Phase ◽  
Sus304 Stainless Steel ◽  
The Stability ◽  
Nose Temperature ◽  
The Magnetic Field

We have investigated effect of magnetic field at cryogenic temperature on the stability of austenitic phase in a sensitized SUS304 stainless steel. The sensitization of the steel was made by heat-treatment in vacuum at 973 K for 100h after the solution treatment at 1323 K for 0.5 h. Isothermal holding of the sensitized specimens was made under a static magnetic field of 5 T in the temperature range between 60 and 260 K for various holding times. As a result, the TTT diagram under the magnetic field corresponding to the formation of 0.5 vol. % of -martensite shows a double-C curve with two noses. We found that by the application of magnetic field, the nose temperature and the incubation time of upper part of the C-curve, that is due to the    transformation, become lower and shorter, respectively. On the other hand, the nose temperature of lower part of the C-curve, that is due to the      transformation, does not change under the magnetic field although the incubation time shortens by the application of magnetic field.

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

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.

scholarly journals Isothermal martensitic transformation in a 12Cr–9Ni–4Mo–2Cu stainless steel in applied magnetic fields

2008 ◽  
Vol 320 (10) ◽  
pp. 1722-1728 ◽  
Author(s):  
D. San Martín ◽  
K.W.P. Aarts ◽  
P.E.J. Rivera-Díaz-del-Castillo ◽  
N.H. van Dijk ◽  
E. Brück ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Martensitic Transformation ◽  
Magnetic Fields ◽  
Isothermal Martensitic Transformation
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