Kinetics of Carbon Partitioning of Q&P Steel: Considering the Morphology of Retained Austenite

The diffusion of carbon atoms from martensite to retained austenite (RA) is controlled by the carbon partitioning kinetics when the quenching and partitioning (Q&P) process is conducted. The RA is divided into film-like and blocky ones in morphology. This research aims to study the influence of the morphology of RA on the kinetics of carbon partitioning mainly by developing a numerical simulation. A one-step Q&P process was modeled at the partitioning temperature of 330–292 °C, with a partitioning time ranging from 10−6 to 5 × 103 s. The finite element method was employed to solve the carbon diffusion equation. A thermomechanical simulator Gleeble-3500 was used to conduct the corresponding Q&P heat treatment, and the RA was examined by X-ray diffraction. The results show that the film-like RA will be enriched in carbon within a short time at first, followed by a decrease in carbon concentration due to the massive absorption of carbon by blocky RA, leading the stable film-like RA to become unstable again. The end of the kinetics of carbon partitioning was the concentration determined by the constrained carbon equilibrium (CCE) model, provided that the CCE condition was employed in this study. It took quite a long time (thousands of seconds) to complete the carbon partitioning globally, which was influenced by the partitioning temperature.

[1]  F. Hu,et al.  Effect of retained austenite on impact toughness and fracture behavior of medium carbon submicron-structured bainitic steel , 2021 .

[2]  Mingxin Huang,et al.  Optimising the strength-ductility-toughness combination in ultra-high strength quenching and partitioning steels by tailoring martensite matrix and retained austenite , 2020 .

[3]  M. Soleimani,et al.  Transformation-induced plasticity (TRIP) in advanced steels: A review , 2020, Materials Science and Engineering: A.

[4]  Binbin He On the Factors Governing Austenite Stability: Intrinsic versus Extrinsic , 2020, Materials.

[5]  J. Kömi,et al.  Precipitation Versus Partitioning Kinetics during the Quenching of Low-Carbon Martensitic Steels , 2020, Metals.

[6]  B. S. Amirkhiz,et al.  Microstructural Evolution During Deformation of a QP980 Steel , 2020, Metallurgical and Materials Transactions A.

[7]  R. Misra,et al.  The impact of periodic distribution of alloying elements during tempering in a multistep partitioned manganese steels on mechanical behavior: Experiments, simulation and analysis , 2019, Materials Science and Engineering: A.

[8]  T. Klein,et al.  Redistribution of C in a Martensite/Austenite Assembly Resulting from Q&P Processing: Computational Modeling Supported by Experiments , 2019, Metallurgical and Materials Transactions A.

[9]  Wei Li,et al.  A Finite-Element Approach for the Partitioning of Carbon in Q&P Steel , 2019, Metallurgical and Materials Transactions B.

[10]  A. Behera,et al.  Prediction of Carbon Partitioning and Austenite Stability via Non-equilibrium Thermodynamics in Quench and Partition (Q&P) Steel , 2019, JOM.

[11]  D. Ponge,et al.  Carbon and strain partitioning in a quenched and partitioned steel containing ferrite , 2019, Acta Materialia.

[12]  Xianghua Liu,et al.  Effect of Micro‐Alloying Elements on Microstructure and Mechanical Properties in C–Mn–Si Quenching and Partitioning (Q&P) Steels , 2018, steel research international.

[13]  A. Behera,et al.  Nonequilibrium thermodynamic modeling of carbon partitioning in quench and partition (Q&P) steel , 2018 .

[14]  Xianghua Liu,et al.  Comparative study on microstructure and mechanical properties of a C-Mn-Si steel treated by quenching and partitioning (Q&P) processes after a full and intercritical austenitization , 2017 .

[15]  T. Gerber,et al.  Impact of Si on Microstructure and Mechanical Properties of 22MnB5 Hot Stamping Steel Treated by Quenching & Partitioning (Q&P) , 2017, Metallurgical and Materials Transactions A.

[16]  J. Masse,et al.  Influence of partitioning on mechanical behavior of Q&P steels , 2016 .

[17]  B. C. Cooman,et al.  Kinetics of the partitioning of carbon and substitutional alloying elements during quenching and partitioning (Q&P) processing of medium Mn steel , 2016 .

[18]  J. Sietsma,et al.  Interaction of carbon partitioning, carbide precipitation and bainite formation during the Q&P process in a low C steel , 2016 .

[19]  H. Nakashima,et al.  In-situ study of the deformation-induced rotation and transformation of retained austenite in a low-carbon steel treated by the quenching and partitioning process , 2016 .

[20]  P. Rivera-Díaz-del-Castillo,et al.  A model for the microstructure behaviour and strength evolution in lath martensite , 2015 .

[21]  Zhen-Yu Liu,et al.  Correlation between mechanical properties and retained austenite characteristics in a low-carbon medium manganese alloyed steel plate , 2015 .

[22]  L. Kestens,et al.  Factors influencing the austenite stability during tensile testing of Quenching and Partitioning steel determined via in-situ electron backscatter diffraction , 2015 .

[23]  D. Raabe,et al.  Effects of retained austenite volume fraction, morphology, and carbon content on strength and ductility of nanostructured TRIP-assisted steels , 2015 .

[24]  J. Seol,et al.  Nano-scale observation on the transformation behavior and mechanical stability of individual retained austenite in CMnSiAl TRIP steels , 2015 .

[25]  D. Raabe,et al.  Carbon partitioning during quenching and partitioning heat treatment accompanied by carbide precipitation , 2015 .

[26]  G. Gao,et al.  Enhanced ductility and toughness in an ultrahigh-strength Mn-Si-Cr-C steel: The great potential of ultrafine filmy retained austenite , 2014 .

[27]  J. Yang,et al.  Stability of retained austenite in multi-phase microstructure during austempering and its effect on the ductility of a low carbon steel , 2014 .

[28]  Wei Li,et al.  Effect of Retained Austenite on the Fracture Toughness of Quenching and Partitioning (Q&P)-Treated Sheet Steels , 2014, Metallurgical and Materials Transactions A.

[29]  Hao Yu,et al.  Microstructure development and mechanical properties of quenching and partitioning (Q&P) steel and an incorporation of hot-dipping galvanization during Q&P process , 2013 .

[30]  Bing Chen,et al.  The effect of morphology on the stability of retained austenite in a quenched and partitioned steel , 2013 .

[31]  J. Sietsma,et al.  Deformation-induced austenite grain rotation and transformation in TRIP-assisted steel , 2012 .

[32]  J. Speer,et al.  Influence of interface mobility on the evolution of austenite-martensite grain assemblies during annealing , 2009 .

[33]  D. Matlock,et al.  Influence of carbon partitioning kinetics on final austenite fraction during quenching and partitioning , 2009 .

[34]  D. Matlock,et al.  Carbon partitioning to austenite from martensite or bainite during the quench and partition (Q&P) process: A critical assessment , 2008 .

[35]  K. Hono,et al.  Effect of partitioning of Mn and Si on the growth kinetics of cementite in tempered Fe–0.6 mass% C martensite , 2007 .

[36]  D. Matlock,et al.  Quenching and partitioning martensite-a novel steel heat treatment , 2006 .

[37]  Francisca García Caballero,et al.  Determination of Ms Temperature in Steels: A Bayesian Neural Network Model , 2002 .

[38]  J. Ågren A revised expression for the diffusivity of carbon in binary FeC austenite , 1986 .

[39]  John Ågren,et al.  Numerical treatment of diffusional reactions in multicomponent alloys , 1982 .