scholarly journals Interaction of martensite and bainite transformations and its dependence on quenching temperature in intercritical quenching and partitioning steels

2019 ◽  
Vol 181 ◽  
pp. 107921 ◽  
Author(s):  
Fei Peng ◽  
Yunbo Xu ◽  
Jiayu Li ◽  
Xingli Gu ◽  
Xu Wang
Keyword(s):  
Quenching Temperature ◽  
Quenching And Partitioning

scholarly journals Effect of Quenching and Partitioning Temperatures in the Q-P Process on the Properties of AHSS with Various Amounts of Manganese and Silicon

2012 ◽  
Vol 706-709 ◽  
pp. 2734-2739 ◽  
Author(s):  
Hana Jirková ◽  
Ludmila Kučerová ◽  
Bohuslav Mašek
Keyword(s):  
Tensile Strength ◽  
Retained Austenite ◽  
Isothermal Holding ◽  
Bainitic Ferrite ◽  
High Strength Steels ◽  
High Strength ◽  
Experimental Program ◽  
Quenching Temperature ◽  
Quenching And Partitioning ◽  
Advanced High Strength Steels

The use of the combined influence of retained austenite and bainitic ferrite to improve strength and ductility has been known for many years from the treatment of multiphase steels. Recently, the very fine films of retained austenite along the martensitic laths have also become the centre of attention. This treatment is called the Q-P process (quenching and partitioning). In this experimental program the quenching temperature and the isothermal holding temperature for diffusion carbon distribution for three advanced high strength steels with carbon content of 0.43 % was examined. The alloying strategies have a different content of manganese and silicon, which leads to various martensite start and finish temperatures. The model treatment was carried out using a thermomechanical simulator. Tested regimes resulted in a tensile strength of over 2000MPa with a ductility of above 14 %. The increase of the partitioning temperature influenced the intensity of martensite tempering and caused the decrease of tensile strength by 400MPa down to 1600MPa and at the same time more than 10 % growth of ductility occurred, increasing it to more than 20%.

Effect of Quenching and Partitioning Processing on Microstructure and Mechanical Properties of a Low Alloyed Steel

2018 ◽  
Vol 941 ◽  
pp. 52-57
Author(s):  
Bernd Pfleger ◽  
Marina Gruber ◽  
Gerald Ressel ◽  
Peter Gruber ◽  
Matthew Galler ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Phase Evolution ◽  
Tensile Tests ◽  
Austenite Phase ◽  
Phase Fraction ◽  
Quenching Temperature ◽  
Quenching And Partitioning ◽  
Low Alloyed Steel ◽  
A Minor

The concept of quenching and partitioning (Q&P) is a tool to generate steels with high strength and high ductility resulting from a relatively high amount of martensite and austenite. As the parameters of the Q&P treatment influence the strength and ductility properties, the goal of this work was to analyze the effects of varying quenching and partitioning temperatures on the phase evolution, on the retained austenite phase fraction and on the mechanical properties. The phase evolution during heat treatment was analyzed by dilatometer and the microstructure after processing was characterized by light microscopy in combination with color etching according to Klemm. The austenite phase fraction and its carbon content were determined by X-Ray diffraction and the mechanical properties were evaluated by tensile tests. It is shown that the quenching temperature has a minor impact on the phase fraction of austenite as well as its stabilization by carbon and thus, also the mechanical properties. Furthermore, austenite transformation during the partitioning treatment is illustrated.

Effects of Quenching and Partitioning Process on Mechanical Properties of a Hot-Stamping Steel

2014 ◽  
Vol 788 ◽  
pp. 340-345 ◽  
Author(s):  
Ming Cheng ◽  
Hong Wu Song ◽  
Xin Li ◽  
Shi Hong Zhang ◽  
Ming Cheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Treatment Process ◽  
Volume Fraction ◽  
Hot Stamping ◽  
Quenching Temperature ◽  
Quenching And Partitioning ◽  
22Mnb5 Steel ◽  
Partitioning Time ◽  
Hot Stamping Steel ◽  
Quenching And Partitioning Process

As a novel heat treatment process, Q&P (quenching and partitioning) process can be applied to enhance the ductility of steels. In this paper, the effects of different parameters of Q&P process (such as quenching temperature, partitioning temperature and partitioning time) on mechanical properties and microstructure of 22MnB5 steel was investigated. Analysis demonstrated that austenite can be stabilized via Q&P process and the volume fraction of retained austenite increases with the partitioning temperature and the partitioning time. The mechanical properties of the steel can be controlled to acquire the steel with excellent strength-ductility balance by Q&P process.

scholarly journals A Study of the Optimum Quenching Temperature of Steels with Various Hot Rolling Microstructures after Cold Rolling, Quenching and Partitioning Treatment

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 579 ◽  
Author(s):  
Bin Chen ◽  
Juhua Liang ◽  
Tao Kang ◽  
Ronghua Cao ◽  
Cheng Li ◽  
...  
Keyword(s):  
Electron Backscatter Diffraction ◽  
High Strength ◽  
Quenching Temperature ◽  
Austenite Grain Size ◽  
Quenching And Partitioning ◽  
Transmission Electron ◽  
Cold Rolled ◽  
Lower Temperature ◽  
Means Of Transmission ◽  
Hot Rolled

Quenching and partitioning (Q&P) processes were applied to a cold-rolled high strength steel (0.19C-1.26Si-2.82Mn-0.92Ni, wt %). The effects of the prior hot-rolled microstructure on the optimum quenching temperature of the studied steels were systematically investigated. The microstructure was analyzed by means of transmission electron microscope (TEM), electron backscatter diffraction (EBSD) and X-ray diffraction (XRD). Compared with the ferrite pearlite mixture matrix, the lower martensite start (Ms) temperature and smaller prior austenite grain size in the cold-rolled martensite matrix are the main reasons for the optimum quenching temperature shifting to a lower temperature in the Q&P steels. We found that an empirical formula that only considers the influence of the alloy composition in the calculation of the Ms temperature will cause a certain interference to the pre-determined optimum quenching temperature of the Q&P steel.

A New Hot Stamping Process with Quenching and Partitioning Treatment

2015 ◽  
Vol 1095 ◽  
pp. 673-676 ◽  
Author(s):  
Pei Xing Liu ◽  
Xiang Yun Yu ◽  
Kai Wang ◽  
Bin Zhu ◽  
Jian Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Retained Austenite ◽  
Hot Stamping ◽  
Quenching Temperature ◽  
Quenching And Partitioning ◽  
Servo Press ◽  
Stamping Process ◽  
Partitioning Time

A new hot stamping process with quenching and partitioning treatment is proposed in the paper. Compared to direct hot stamping process, the microstructures with some retained austenite not only including martensite are formed according to the constrained carbon equilibrium (CCE) model. During the new hot stamping process, tools with high temperature are used to control the quenching temperature (QT) between Ms and Mf, and the partitioning treatment of the part is also implemented in the tools by prolonging holding times. In this paper, different holding times (partitioning times) controlled by servo press, are used to research the influence of partitioning time on mechanical properties.

scholarly journals Microstructure Analysis and Mechanical Properties of Low Alloy High Strength Quenched and Partitioned Steel

2016 ◽  
Vol 258 ◽  
pp. 574-578 ◽  
Author(s):  
Farnoosh Forouzan ◽  
Suresh Gunasekaran ◽  
Ali Hedayati ◽  
Esa Vuorinen ◽  
Frank Mücklich
Keyword(s):  
Mechanical Properties ◽  
Retained Austenite ◽  
Lath Martensite ◽  
High Strength ◽  
Microstructure Analysis ◽  
Quenching Temperature ◽  
Precipitate Formation ◽  
Quenching And Partitioning ◽  
Fine Grained ◽  
Impact Tests

Gleeble study of the quenching and partitioning (Q&P) process has been performed on Domex 960 steel (Fe, 0.08 %C, 1.79 %Mn, 0.23 %Si, 0.184 %Ti, and 0.038 %Al). The effect of different Q&P conditions on microstructure and mechanical properties were investigated. The aim of the process is to produce a fine grained microstructure for better ductility and controlled amounts of different micro-constituents to increase the strength and toughness simultaneously. Three different quenching temperatures, three partitioning temperatures and three partitioning times have been selected to process the 27 specimens by Gleeble® 1500. The specimens were characterized by means of OM, SEM, XRD, hardness and impact tests. It was found that, fine lath martensite with retained austenite is achievable without high amount of Si or Al in the composition although lack of these elements may cause the formation of carbides and decrease the available amount of carbon for partitioning into the austenite. The hardness increases as the quenching temperature is decreased, however, at highest partitioning temperature (640◦C) the hardness increases sharply due to extensive precipitate formation.

Effect of quenching temperature on stretch flangeability of a medium Mn steel processed by quenching and partitioning

2018 ◽  
Vol 729 ◽  
pp. 276-284 ◽  
Author(s):  
Ji Hoon Kim ◽  
Eun Jung Seo ◽  
Min-Hyeok Kwon ◽  
Singon Kang ◽  
Bruno C. De Cooman
Keyword(s):  
Quenching Temperature ◽  
Quenching And Partitioning ◽  
Medium Mn Steel ◽  
Mn Steel

scholarly journals Influence of the Quenching and Partitioning Process on the Transformation Kinetics and Hardness in a Lean Medium Manganese TRIP Steel

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 353 ◽  
Author(s):  
Simone Kaar ◽  
Reinhold Schneider ◽  
Daniel Krizan ◽  
Coline Béal ◽  
Christof Sommitsch
Keyword(s):  
Isothermal Holding ◽  
Bainitic Ferrite ◽  
High Strength ◽  
Quenching Temperature ◽  
Quenching And Partitioning ◽  
Novel Approach ◽  
Medium Mn Steel ◽  
C Partitioning ◽  
Mn Steel ◽  
Isothermal Bainitic Transformation

The quenching and partitioning (Q&P) process of lean medium Mn steels is a novel approach for producing ultra-high strength and good formable steels. First, the steel is fully austenitized, followed by quenching to a specific quenching temperature (TQ) in order to adjust an appropriate amount of initial martensite (α’initial). Subsequently, the steel is reheated to a partitioning temperature (TP) in order to ensure C-partitioning from α’initial to remaining austenite (γremain) and thus retained austenite (RA) stabilization. After isothermal holding, the steel is quenched to room temperature (RT), in order to achieve a martensitic-austenitic microstructure, where the meta-stable RA undergoes the strain-induced martensitic transformation by the so-called transformation induced plasticity (TRIP) effect. This paper systematically investigates the influence of the Q&P process on the isothermal bainitic transformation (IBT) kinetics in a 0.2C-4.5Mn-1.3Al lean medium Mn steel by means of dilatometry. Therefore, the Q&P annealing approach was precisely compared to the TRIP-aided bainitic ferrite (TBF) process, where the samples were directly quenched to the temperature of the IBT after full austenitization. The results indicated an accelerated IBT for the Q&P samples, caused by the formation of α’initial during quenching below the martensite start (MS) temperature. Furthermore, a significant influence of the annealing parameters, such as TQ and TP, was observed with regard to the transformation behavior. For further characterization, light optical microscopy (LOM) and scanning electron microscopy (SEM) were applied, showing a microstructure consisting of a martensitic-bainitic matrix with finely distributed RA islands. Saturation magnetization method (SMM) was used to determine the amount of RA, which was primarily depending on TQ. Furthermore, the hardness according to Vickers revealed a remarkable impact of the annealing parameters, such as TQ and TP, on the predicted mechanical properties.

Sign in / Sign up

Export Citation Format

Share Document