Kinetics modeling of austenite decomposition for an end-quenched 1045 steel

Lee, Seok-Jae; Pavlina, Erik J.; Tyne, C. J. Van

doi:10.1016/j.msea.2010.01.081

Cited by 46 publications

(21 citation statements)

References 30 publications

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“…Consequently a new approach was introduced using the constitutive equation of Lee et al (2010) for modelling diffusionless kinetics of phase transformation. Since the formation of martensite is a time-independent process, Eq.…”

Section: Modelling Diffusionless Kinetics Of Phase Transformationmentioning

confidence: 99%

“…Here, m is the volume fraction of martensite, M s the martensite start temperature and T the current temperature. The parameters ˛, n, ϕ m and m are material model parameters that influence the incubation time and the rate of formation d m /dT in dependency to the austenite grain size (Lee et al, 2010). The austenite grain size corresponds to G ASTM = 11 and the martensite start temperature is 410 • C.…”

Section: Modelling Diffusionless Kinetics Of Phase Transformationmentioning

confidence: 99%

“…To use the model proposed by Lee et al (2010) also for processes and cooling paths with a previous formation of diffusion controlled volume fractions it is mandatory to model the rate of formation of martensite d m /dT with a normalized fraction m called the ghost fraction as shown in Eq. (2).…”

Section: Modelling Diffusionless Kinetics Of Phase Transformationmentioning

confidence: 99%

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Modelling kinetics of phase transformation for the indirect hot stamping process to focus on car body parts with tailored properties

Hippchen

Lipp

Grass

et al. 2016

Journal of Materials Processing Technology

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Please cite this article in press as: Hippchen, P., et al., Modelling kinetics of phase transformation for the indirect hot stamping process to focus on car body parts with tailored properties. J. Mater. Process. Tech. (2015), http://dx. a b s t r a c tTo design the indirect hot stamping process, a finite element method (FEM) based prediction of the part geometry and the mechanical properties is required. In case of indirect hot stamping processes, producing car body parts with tailored properties, cooling paths occur causing diffusionless and diffusion controlled phase transformations. The volume expansion caused by the phase transformation of face-centred cubic (fcc) into body-centred cubic (bcc) and the martensitic formation of body-centred tetragonal (bct) leads to transformation induced strains that are important for the calculation of overall stresses in hot stamped car body parts. To calculate the strain and stress state correctly, it is necessary to model the diffusionless and diffusion controlled phase transformation phenomena, taking into account the boundary conditions of indirect hot stamping processes. The existing material models are analysed and extended in order to improve their prediction accuracy in calculating the amount and distribution of ferrite, perlite, bainite and martensite during the whole process of annealing. For industrial use the new approaches are implemented in the FE-code LS-DYNA 971 (Livermore Software Technology Corporation, 2006).

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Section: Modelling Diffusionless Kinetics Of Phase Transformationmentioning

confidence: 99%

Section: Modelling Diffusionless Kinetics Of Phase Transformationmentioning

confidence: 99%

See 1 more Smart Citation

Modelling kinetics of phase transformation for the indirect hot stamping process to focus on car body parts with tailored properties

Hippchen

Lipp

Grass

et al. 2016

Journal of Materials Processing Technology

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“…where latent heats DH k of 89.4, 77.5, 66.5, and 81.5 kJ/kg for k = 1, 2, 3, and 4, respectively, were selected from the literature (Lee et al, 2010). The other thermal properties such as the density q, specific heat c p , and conductivity k were also modeled as functions of temperature or both temperature and phase fractions, namely,…”

Section: Implementing Materials Models Via User-defined Subroutinesmentioning

confidence: 99%

Stress development and shape change during press-hardening process using phase-transformation-based finite element analysis

Bok

Choi

Suh

et al. 2015

International Journal of Plasticity

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“…A fonte de calor tridimensional e transiente (representadas pelas Equações 2 e 3) são incluídas no termo fonte da Equação 1 e pode-se, portanto, resolver o problema acoplado considerando as não linearidades devidas a propriedades termofísicas (dependentes da temperatura e composição) e à fonte de calor móvel do modelo duplo-elipsóide descrito pelas Equações 2 e 3. A convecção e radiação nas superfícies da chapa, classicamente descritos por qc=h(T-T0) e qr=εσ(T 4 -T0 4 ), respectivamente [11]. Onde qc e qr são respectivamente o calor gerado à frente e atrás da tocha, T a temperatura final e T0 a inicial, σ é a constante de stefan boltzmann (σ= 5,67×10 .K).…”

Section: Estudo Numérico E Experimental Da Evolução Microestrutural Eunclassified

Estudo Numérico e Experimental da Evolução Microestrutural e das Propriedades de Juntas Soldadas de Vergalhões pelo Processo GMAW

et al. 2015

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Este é um artigo publicado em acesso aberto (Open Access) sob a licença Creative Commons Attribution Non-Commercial, que permite uso, distribuição e reprodução em qualquer meio, sem restrições desde que sem fins comerciais e que o trabalho original seja corretamente citado. Resumo: Este trabalho constitui um estudo dos vergalhões CA-50 da classe dos aços SAE 1026. Para um melhor controle das propriedades mecânicas da junta soldada foi realizado este estudo, o conhecimento de certas variáveis é de grande importância para encontrar os parâmetros ideais de soldagem, e os respectivos resultados microestruturais e consequentemente sobre as propriedades mecânicas da junta soldada. Para realização deste estudo foi realizado um estudo do material como recebido para a fixação de uma base sólida de comparação. Foi realizada a soldagem do material utilizando como gás de proteção argônio com 20% de dióxido de carbono, o arame utilizado foi o cobreado ER70S-6, as juntas soldadas foram do tipo transpasse com monitoramento de temperatura através de termopares para dois aportes térmicos distintos. Um código numérico computacional foi desenvolvido para simular os fenômenos que ocorrem no processo (gradiente de temperatura, transformações de fases, transferência de calor). As juntas soldadas não apresentaram martensita como fase frágil, o metal de solda apresentou estrutura dendrítica, a ZTA apresentou duas regiões distintas com tamanhos de grão diferentes tudo isso devido ao gradiente de temperatura, que também originou características distintas do cordão de solda, ZTA, fases formadas e tamanhos de grão distintos. Palavras-chave:Soldabilidade; GMAW; Simulação computacional; Concreto armado. Numerical and Experimental Study of Microstructure Evolution and Properties of Welded Joints of Rebars by GMAW ProcessAbstract: This work is a study of rebar CA-50 class of steels SAE 1026. To better control the mechanical properties of the weld was carried out this study, knowledge of certain variables is very important to find the optimal parameters of welding, and the results microstructure and therefore on the mechanical properties of the welded joint. For this study was conducted a study of the material as received for establishing a solid basis for comparison. Welding the material using argon as protective gas of 20% carbon dioxide was performed, the wire used was ER70S-6 coppered, welded joints were of the type with crossover temperature monitoring thermocouple through two distinct thermal contributions. A computational numerical code was developed to simulate the phenomena occurring in the process (temperature gradient, phase transformations, heat transfer). Welded joints did not show how fragile martensite phase, the weld metal showed dendritic structure, the ZTA presented two distinct regions with different grain sizes all this due to the temperature gradient, which also originated distinct characteristics of the weld bead, ZTA, stages formed and different grain sizes.

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Kinetics modeling of austenite decomposition for an end-quenched 1045 steel

Cited by 46 publications

References 30 publications

Modelling kinetics of phase transformation for the indirect hot stamping process to focus on car body parts with tailored properties

Modelling kinetics of phase transformation for the indirect hot stamping process to focus on car body parts with tailored properties

Stress development and shape change during press-hardening process using phase-transformation-based finite element analysis

Estudo Numérico e Experimental da Evolução Microestrutural e das Propriedades de Juntas Soldadas de Vergalhões pelo Processo GMAW

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