Quenching above martensite start temperature in quenching and partitioning (Q&P) steel through control of partial phase transformation

2018 ◽  
Vol 230 ◽  
pp. 36-39 ◽  
Author(s):  
Y.J. Li ◽  
D. Liu ◽  
W.N. Zhang ◽  
J. Kang ◽  
D. Chen ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Quenching And Partitioning ◽  
Partial Phase ◽  
Start Temperature

Stepwise conductance control of niobium nanocontacts by partial phase transformation

2021 ◽  
pp. 110247
Author(s):  
Yusuke Ochiai ◽  
Takuya Obi ◽  
Yuuki Tsuruoka ◽  
Tokushi Kizuka
Keyword(s):  
Phase Transformation ◽  
Partial Phase

scholarly journals Microstructure and Phase Transformation Analysis of Ni50−xTi50Lax Shape Memory Alloys

Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 345 ◽  
Author(s):  
Weiya Li ◽  
Chunwang Zhao
Keyword(s):  
Phase Transformation ◽  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Martensite Transformation ◽  
Transformation Behavior ◽  
Ni Content ◽  
Start Temperature

The microstructure and martensitic transformation behavior of Ni50−xTi50Lax (x = 0.1, 0.3, 0.5, 0.7) shape memory alloys were investigated experimentally. Results show that the microstructure of Ni50−xTi50Lax alloys consists of a near-equiatomic TiNi matrix, LaNi precipitates, and Ti2Ni precipitates. With increasing La content, the amounts of LaNi and Ti2Ni precipitates demonstrate an increasing tendency. The martensitic transformation start temperature increases gradually with increasing La content. The Ni content is mainly responsible for the change in martensite transformation behavior in Ni50−xTi50Lax alloys.

Influence of Mn and Ni on Austenite Stabilization during a High Temperature Q&P Treatment

2021 ◽  
Vol 1016 ◽  
pp. 379-384
Author(s):  
Eider Del Molino ◽  
Teresa Gutierrez ◽  
Mónica Serna-Ruiz ◽  
Maribel Arribas ◽  
Artem Arlazarov
Keyword(s):  
Phase Transformation ◽  
Electron Microscope ◽  
High Temperature ◽  
Retained Austenite ◽  
Nickel Content ◽  
X Ray Diffraction ◽  
Quenching And Partitioning ◽  
X Ray ◽  
Scanning Electron ◽  
P Cycle

The aim of this work was to study the influence of quenching and partitioning temperatures combined with various levels of Mn and Ni contents on the austenite stabilization along the quenching and partitioning (Q&P) cycle. Three steels with 2 wt.%, 4 wt.% and 6 wt.% manganese and one steel with 2 wt.% nickel content were investigated. Phase transformation temperatures and critical cooling rates were obtained experimentally using dilatometer for each alloy. Q&P cycles with different quenching and partitioning temperatures were also done in dilatometer, thus, allowing monitoring of the expansion/contraction during the whole Q&P cycle. Microstructure characterization was performed by means of a Scanning Electron Microscope and X-Ray Diffraction to measure retained austenite content. It was found that, strongly depending on the Q&P conditions, austenite stabilization or decomposition occurs during partitioning and final cooling. In case of high partitioning temperature cycles, austenite reverse transformation was observed. Certain cycles resulted in a very effective austenite stabilization and interesting microstructure.

Orientation Relationship during Partial α-γ-Phase Transformation in Microalloyed Steels

2005 ◽  
Vol 495-497 ◽  
pp. 447-452 ◽  
Author(s):  
I. Lischewski ◽  
Günter Gottstein
Keyword(s):  
Phase Transformation ◽  
Orientation Relationship ◽  
Microalloyed Steel ◽  
Austenite Phase ◽  
Microalloyed Steels ◽  
Special Focus ◽  
Partial Phase ◽  
Growth Selection

The ferrite to austenite phase transformation in microalloyed steel was studied, with a special focus on the orientation relationship between prior ferrite and subsequent austenite. Also the role of growth selection and preferred nucleation was investigated in this context. Their effects were examined at partial phase transformation.

Study of Phase Transformation of Medium Carbon Steel after Hot Plastic Deformation

2016 ◽  
Vol 258 ◽  
pp. 599-602
Author(s):  
Rostislav Kawulok ◽  
Ivo Schindler ◽  
Petr Kawulok ◽  
Janusz Dänemark ◽  
Petr Opěla ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Phase Transformation ◽  
Carbon Steel ◽  
Medium Carbon Steel ◽  
Transformation Kinetics ◽  
Bainite Transformation ◽  
Cooling Rates ◽  
Hot Plastic Deformation ◽  
Medium Carbon ◽  
Start Temperature

The CCT and DCCT diagrams of steel C60 (with approx. 0.6 % C) were constructed on the basis of dilatation tests with and/or without an influence of the previous deformation and they were then compared, order to make an evaluation of the influence of the previous deformation on the phase transformation kinetics. For the execution of the experiment, the dilatation module of the plastometer Gleeble 3800 was used. The accuracy of the diagrams was faced with metallographic analyses and measurements. The previous deformation expressly retarded a bainite transformation and slightly accelerated ferrite and pearlite transformations. The martensite start temperature was practically not influenced by the previous deformation; however, the applied deformation caused the creation of the martensite at lower cooling rates.

scholarly journals An original unified approach for the description of phase transformations in steel during cooling: first application to binary Fe–C

2019 ◽  
Vol 116 (6) ◽  
pp. 615
Author(s):  
Olivier Bouaziz
Keyword(s):  
Phase Transformation ◽  
Phase Transformations ◽  
Order Parameter ◽  
Second Step ◽  
Global Approach ◽  
Unified Approach ◽  
Original Order ◽  
Thermodynamic Conditions ◽  
Start Temperature

Exploiting Landau’s theory of phase transformations, defining an original order parameter and using the phenomenological transformation temperatures, it is reported that it is possible to describe in a global approach the conditions for the formation of each constituent (ferrite, bainite, martensite) from austenite during cooling in steel. It allowed to propose a new rigorous classification of the different thermodynamic conditions controlling each phase transformation. In a second step, the approach predicts naturally the effect of cooling rate on the bainite start temperature. Finally, perspectives are assessed to extend the approach in order to take into account the effect of an external field such as applied stress.

The Effect of Bainitic Transformation on Martensite Start Temperature of a Fe-C-Mn-Si Alloy

2011 ◽  
Vol 415-417 ◽  
pp. 974-978
Author(s):  
Guang Xu ◽  
Hang Zou ◽  
Cong Hua Bu
Keyword(s):  
Phase Transition ◽  
Phase Transformation ◽  
Bainitic Transformation ◽  
Mechanical Stabilization ◽  
Start Temperature

The martensite start temperature (Ms) of a Fe-0.40%C-1.87%Mn-1.65%Si alloy with bainite and martensite dual phases was studied. The phase transformation dilation curves were measured and Ms temperatures of deformed and non-deformed specimens were obtained. Finally the effect of bainitic transformation upon Ms was investigated. The results show that bainitic phase transition affects the Ms and the increase of transformation results in the decrease of Ms. The mechanical stabilization of austenite due to ausforming is partially eliminated by bainitic transformation, which weakens the effect of ausforming on Ms.

Sign in / Sign up

Export Citation Format

Share Document