scholarly journals Study and modelling of the influence of second phase particles on the austenite grain growth in a niobium microalloyed steel

2006 ◽  
Vol 42 (2) ◽  
Author(s):  
D. San Martín ◽  
F. G. Caballero ◽  
C. Capdevila ◽  
C. García-de-Andrés
Keyword(s):  
Grain Growth ◽  
Microalloyed Steel ◽  
Second Phase ◽  
Austenite Grain ◽  
Second Phase Particles ◽  
Niobium Microalloyed Steel ◽  
Austenite Grain Growth

scholarly journals Discussion on the Rate Controlling Process of Coarsening of Niobium Carbonitrides in a Niobium Microalloyed Steel

2005 ◽  
Vol 500-501 ◽  
pp. 703-710 ◽  
Author(s):  
David San Martín ◽  
Francisca García Caballero ◽  
Carlos Capdevila ◽  
Carlos García de Andrés
Keyword(s):  
Grain Growth ◽  
Volume Diffusion ◽  
Microalloyed Steels ◽  
Second Phase ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
The Matrix ◽  
Niobium Microalloyed Steel ◽  
Grain Growth Kinetics ◽  
Austenite Grain Growth

Austenite grain growth in microalloyed steels is governed by the coarsening of fine precipitates present at grain boundaries below the grain coarsening temperature. Zener model is widely used in metals to describe the pinning effect of second phase particles precipitated in the matrix. In this work it has been discussed whether grain boundary or volume diffusion is the rate controlling process for the coarsening of the niobium carbonitrides. Calculations on austenite grain growth kinetics, obtained coupling Zener theory and both rate controlling processes of precipitate coarsening, have been compared against experimental austenite grain size results under nonisothermal heating conditions. In this sense, it has been concluded that the coarsening of niobium carbonitrides is mainly controlled by volume diffusion of Nb in austenite.

Effect of Rare Earth (RE) La on Solid Solution of Second Phase Particle and Austenite Grain Growth in Steel Containing High Niobium

2011 ◽  
Vol 189-193 ◽  
pp. 2869-2874 ◽  
Author(s):  
Wen Zhong Song ◽  
Qi Fang ◽  
Hui Ping Ren ◽  
Zi Li Jin ◽  
Hui Chang
Keyword(s):  
Solid Solution ◽  
Growth Rate ◽  
Rare Earth ◽  
Grain Growth ◽  
Phase Particle ◽  
Solution Temperature ◽  
Second Phase ◽  
Austenite Grain ◽  
Austenite Grain Growth ◽  
Soaking Temperature

The solid solution of the second phase particle and austenite grain growth behavior of the high niobium-containing RE steel was studied by mathematical calculation and extraction replica technique. The purpose of the study was to investigate the effects of Rare Earth La on austenite grain growth and propose an empirical equation for predicting the austenite grain size of RE steel. Austenite grain grows in an exponential law with the increase of heating temperature, while approximately in a parabolic law with the increase of holding time. Results show that the RE steel has good anti-coarsening ability at elevated temperatures. When soaking temperature is lower than 1250°C , AGS and growth rate are small for high niobium steel, but soaking temperature is lower than 1220°C , AGS and growth rate are small for RE steel. RE La can promote solid solution of second-phase particles Nb(C, N), the solution temperature decrease 30°C than high niobium steel.

Austenite Grain Growth in Heat Affected Zone of Zr-Ti Bearing Microalloyed Steel

2012 ◽  
Vol 19 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Lei Zheng ◽  
Ze-xi Yuan ◽  
Shen-hua Song ◽  
Tian-hui Xi ◽  
Qian Wang
Keyword(s):  
Grain Growth ◽  
Heat Affected Zone ◽  
Microalloyed Steel ◽  
Austenite Grain ◽  
Austenite Grain Growth

scholarly journals Austenite grain growth calculation of 0.028% Nb steel

2011 ◽  
Vol 47 (2) ◽  
pp. 199-209 ◽  
Author(s):  
D. Priadi ◽  
R.A.M. Napitupulu ◽  
E.S. Siradj
Keyword(s):  
Mathematical Model ◽  
Grain Growth ◽  
Process Design ◽  
Microalloyed Steel ◽  
Model Fit ◽  
Growth Data ◽  
Austenite Grain Size ◽  
Quantitative Calculation ◽  
Austenite Grain ◽  
Austenite Grain Growth

Modeling of microstructural evolution has become a powerful tool for materials and process design by providing quantitative relationships for microstructure, composition and processing. Insufficient attention has been paid to predicting the austenite grain growth of microalloyed steel and the effect of undissolved microalloys. In this research, we attempted to calculate a mathematical model for austenite grain growth of 0.028% Nb steel, which can account for abnormal grain growth. The quantitative calculation of austenite grain growth generated from this model fit well with the experimental grain growth data obtained during reheating of niobium steels. The results of this study showed that increasing the temperature increases the austenite grain size, with a sharp gradient observed at higher temperatures.

scholarly journals In situ measurement and modelling of austenite grain growth in a Ti/Nb microalloyed steel

2012 ◽  
Vol 60 (3) ◽  
pp. 1015-1026 ◽  
Author(s):  
M. Maalekian ◽  
R. Radis ◽  
M. Militzer ◽  
A. Moreau ◽  
W.J. Poole
Keyword(s):  
Grain Growth ◽  
Microalloyed Steel ◽  
In Situ Measurement ◽  
Austenite Grain ◽  
Nb Microalloyed Steel ◽  
Austenite Grain Growth

Austenite Grain Growth Kinetics in a Low C-Mn Steel and a Ti-Nb-V Microalloyed Steel

2014 ◽  
Vol 1019 ◽  
pp. 327-332 ◽  
Author(s):  
K.A. Annan ◽  
C.W. Siyasiya ◽  
W.E. Stumpf ◽  
K.M. Banks ◽  
A.S. Tuling
Keyword(s):  
Grain Growth ◽  
Microalloyed Steel ◽  
Microalloyed Steels ◽  
Growth Equation ◽  
Austenite Grain ◽  
Grain Growth Kinetics ◽  
Increasing Temperature ◽  
Austenite Grain Growth ◽  
Mn Steel ◽  
Good Agreement

The effect of thermal processing (TMP) parameters on grain growth in a low C - Mn steel and a C - Mn steel microalloyed with Nb, Ti and V were compared as part of a wider study on grain growth in microalloyed steels. The grain growth rate was found to be low at low temperatures and short soaking times but increases significantly with both increasing temperature and time. The activation energy Q, the grain growth equation constants n and A were found to be higher in the microalloyed steel than the plain C-Mn steel. A constitutive model for predicting austenite grain growth in the low C-Mn steel and the microalloyed steel has been developed. The predictive potential of the model is in good agreement with the experimental data.

Effect of Precipitates on Austenite Grain Growth Behavior in a Low-Carbon Nb-V Microalloyed Steel

2017 ◽  
Vol 898 ◽  
pp. 783-790 ◽  
Author(s):  
Li Chong Zhang ◽  
Xin Li Wen ◽  
Ya Zheng Liu
Keyword(s):  
Grain Growth ◽  
Microalloyed Steel ◽  
Growth Models ◽  
Energy Dispersive Spectrometer ◽  
Growth Behavior ◽  
Low Carbon ◽  
Dissolution Temperature ◽  
Austenite Grain ◽  
Grain Growth Behavior ◽  
Austenite Grain Growth

The effect of precipitates on austenite grain growth behavior in a Nb-V microalloyed steel was investigated. The precipitates were identified by selected area electron diffraction (SAED) and energy dispersive spectrometer (EDS) analysis. Because of pinning effect of NbC and/or VC on austenite grain boundaries, grains grew slowly at 850oC-1000oC. However, when temperature reached 1050 oC, abnormal grain growth was observed, which was attributed to dissolution of NbC particles. The NbC precipitates dissolved significantly at 1150 oC. However, grain sizes were still very small. Thus, austenite grains grew rapidly at 1050-1150 oC. The fully dissolution temperature of this steel was 1150-1250oC. Finally, the relationship between grain coarsening temperature (TGC) and fully dissolution temperature (TDISS) could be illustrated as follows: 100 oC≤TDISS -TGC≤200 oC. When heating temperatures were 850-1050 oC and 1050-1250 oC, grain growth activation energies (Q) were 59945 J/mol and 135813 J/mol, respectively. The different grain growth models were mainly caused by the gradual dissolution of NbC particles.

Sign in / Sign up

Export Citation Format

Share Document