Computer Model for Prediction of Carbonitride Precipitation during Hot Working in Nb-Ti Bearing HSLA Steels.

Okaguchi, Shuji; Hashimoto, Tamotsu

doi:10.2355/isijinternational.32.283

Cited by 70 publications

(45 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The thermodynamics of precipitation in Nb-Ti steels can be described by the thermodynamic model, [12][13][14][15] which are basis for current modeling and shown in details in Appendix I. The equilibrium compositions of precipitates at different temperatures were calculated using the data ( Table 3) from Ref.…”

Section: Modeling the Precipitation In Steelsmentioning

confidence: 99%

“…[12][13][14][15] Nb and Ti sites are on one sub-lattice (fcc structure), and C and N on on the other sub-lattice (fcc) in the complex precipitates of Ti x Nb 1Ϫx C y N 1Ϫy . Thus, it could be regarded as a complete ideal solid solution of NbC, NbN, TiC and TiN when the interaction between C and N or Ti and Nb is ignored.…”

Section: Appendix Thermodynamic Modeling On Ti X Nb 1ϫx C Y N 1ϫy Prmentioning

confidence: 99%

See 1 more Smart Citation

The Influence of Ti on the Hot Ductility of Nb-bearing Steels in Simulated Continuous Casting Process.

Luo

Karjalainen

Porter³

et al. 2002

ISIJ International

View full text Add to dashboard Cite

The hot ductility of as-cast Nb, Ti and Nb-Ti bearing low-carbon steels has been assessed. Hot tensile testing of in-situ melted specimens, replica examinations and thermodynamic modeling showed that addition of 0.014-0.04%Ti to 0.1%C-0.03%Nb-0.005%N steel leads to a large volume fraction of fine strain-induced precipitates at temperatures up to 1 000°C which seriously deteriorate the hot ductility, in spite of the type of prior thermal history. Generally, three types of precipitates, i.e. coarse boundary precipitate, coarse frond-like and fine strain-induced precipitates, were found in Ti-Nb microalloyed steels with the different sizes and compositions, and the latter could be described by thermodynamic modeling. The current results are different from the previous ones published and a thermodynamic model was employed to explain this discrepancy. Accordingly, the beneficial effect of Ti can only be achieved in some instances at high nitrogen and low titanium contents, i.e. a low Ti/N ratio, which greatly encourages coarse precipitation at high temperatures and reduces the fine strain-induced precipitation. Therefore, only for electric arc steels typically with a high nitrogen level, a small addition of Ti might be considered to be advantageous to the hot ductility.

show abstract

Section: Modeling the Precipitation In Steelsmentioning

confidence: 99%

Section: Appendix Thermodynamic Modeling On Ti X Nb 1ϫx C Y N 1ϫy Prmentioning

confidence: 99%

The Influence of Ti on the Hot Ductility of Nb-bearing Steels in Simulated Continuous Casting Process.

Luo

Karjalainen

Porter³

et al. 2002

ISIJ International

View full text Add to dashboard Cite

show abstract

“…in those TMP conditions where recrystallisation is likely to take place prior to precipitation. It has also been found that the Nb precipitation kinetics (time, temperature and particle size) depend strongly on steel composition, in particular the Nb, Ti, C and N contents [2,[12][13][14][15], as well as strain levels [16][17][18]. An increased Nb and N content enhances Nb(C,N) precipitation.…”

Section: Introductionmentioning

confidence: 99%

“…The presence of Ti retards Nb(C,N) precipitation, due to a decrease in N and Nb content following precipitation of TiN and TiNbrich phases. With an increase in strain, the Nb-rich precipitate size decreases, and the number density increases as a result of strain-induced precipitation on dislocations [5,12,16]. The straininduced precipitation retards recrystallisation by delaying recovery.…”

Section: Introductionmentioning

confidence: 99%

Effect of deformation temperature on niobium clustering, precipitation and austenite recrystallisation in a Nb–Ti microalloyed steel

Kostryzhev

Shahrani

Zhu

et al. 2013

Materials Science and Engineering: A

View full text Add to dashboard Cite

The effect of deformation temperature on Nb solute clustering, precipitation and the kinetics of austenite recrystallisation were studied in a steel containing 0.081C-0.021Ti-0.064 Nb (wt%). Thermo-mechanical processing was carried out using a Gleeble 3500 simulator. The austenite microstructure was studied using a combination of optical microscopy, transmission electron microscopy, and atom probe microscopy, enabling a careful characterisation of grain size, as well as Nb-rich clustering and precipitation processes. A correlation between the austenite recrystallisation kinetics and the chemistry, size and number density of Nb-rich solute atom clusters, and NbTi(C,N) precipitates was established via the austenite deformation temperature. Specifically, we have determined thresholds for the onset of recrystallisation: for deformation levels above 75% and temperatures above 825 °C, Nb atom clusters recrystallisation AbstractThe effect of deformation temperature on Nb solute clustering, precipitation and the kinetics of austenite recrystallisation were studied in a steel containing 0.081C-0.021Ti-0.064Nb (wt. %). Thermo-mechanical processing was carried out using a Gleeble 3500 simulator. The austenite microstructure was studied using a combination of optical microscopy, transmission electron microscopy, and atom probe microscopy, enabling a careful characterisation of grain size, as well as Nb-rich clustering and precipitation processes. A correlation between the austenite recrystallisation kinetics and the chemistry, size and number density of Nb-rich solute atom clusters, and NbTi(C,N) precipitates was established via the austenite deformation temperature. Specifically, we have determined thresholds for the onset of recrystallisation: for deformation levels above 75 % and temperatures above 825 °C, Nb atom clusters < 8 nm effectively suppressed austenite recrystallisation.

show abstract

“…Los diagramas PTT de aceros microaleados determinados por otros autores se realizaron mediante ecuaciones teóricas (12)(13)(14)(15), por microscopía de transmisión (16) o con técnicas de relajación (17).…”

Section: Introductionunclassified

Estudio de la cinética de precipitación inducida mediante la determinación de los diagramas Precipitación-Tiempo-Temperatura (PTT) en aceros microaleados

Medina¹

1995

REVMETAL

View full text Add to dashboard Cite

Resumen Se describe un método desarrollado en el CENIM que permite estudiar la cinética de la precipitación inducida por la deformación en aceros microaleados. Mediante ensayos de torsión, se ha determinado la fracción recristalizada estáticamente de tres aceros microaleados con niobio, vanadio y titanio, respectivamente, a diferentes temperaturas y deformaciones. Cuando la precipitación comienza, la fracción recristalizada se desvía de la ecuación de Avrami y esto permite conocer el instante en el que la precipitación comienza (P^) y el instante en que termina (Pf). De este modo, se pueden trazar las curvas de Precipitación-Tiempo-Temperatura (PTT) que muestran gráficamente la cinética de precipitación.Palabras clave: Recristalización estática. Precipitación inducida. Diagramas PTT. Study of induced precipitation kinetics by means of Precipitation-Time-Temperature diagrams (PTT) determination in microalloyed steelsAbstract A method developed in the CENIM is described which allows to study the induced precipitation kinetics by the deformation in microalloyed steels. By means of torsión tests the statically recristallized fraction of three microalloyed steels with Nb, V or Ti, has been determined to different temperatures and deformations. When the precipitation begins, the recrystallized fraction is separated of the Avrami's equation and this allows to know the instant the precipitation begins (P^) and the instant the precipitation finishes (Pf). Thereby can be traced the Precipitation-Time-Temperature (PTT) diagrams which graphically show the precipitation kinetics.

show abstract

Computer Model for Prediction of Carbonitride Precipitation during Hot Working in Nb-Ti Bearing HSLA Steels.

Cited by 70 publications

References 0 publications

The Influence of Ti on the Hot Ductility of Nb-bearing Steels in Simulated Continuous Casting Process.

The Influence of Ti on the Hot Ductility of Nb-bearing Steels in Simulated Continuous Casting Process.

Effect of deformation temperature on niobium clustering, precipitation and austenite recrystallisation in a Nb–Ti microalloyed steel

Estudio de la cinética de precipitación inducida mediante la determinación de los diagramas Precipitación-Tiempo-Temperatura (PTT) en aceros microaleados

Contact Info

Product

Resources

About