Study of austenite grain size of microalloyed steel by simulating initial solidification during continuous casting

2014 ◽  
Vol 42 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Y. Li ◽  
G. Wen ◽  
L. Luo ◽  
J. Liu ◽  
P. Tang
Keyword(s):  
Grain Size ◽  
Continuous Casting ◽  
Microalloyed Steel ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Initial Solidification

Influence of austenite grain size on recrystallisation–precipitation interaction in a V-microalloyed steel

2007 ◽  
Vol 447 (1-2) ◽  
pp. 11-18 ◽  
Author(s):  
A. Quispe ◽  
S.F. Medina ◽  
M. Gómez ◽  
J.I. Chaves
Keyword(s):  
Grain Size ◽  
Microalloyed Steel ◽  
Austenite Grain Size ◽  
Austenite Grain

Prediction for the austenite grain size in the presence of growing particles in the weld HAZ of Ti-microalloyed steel

2007 ◽  
Vol 459 (1-2) ◽  
pp. 40-46 ◽  
Author(s):  
Joonoh Moon ◽  
Jongbong Lee ◽  
Changhee Lee
Keyword(s):  
Grain Size ◽  
Microalloyed Steel ◽  
Austenite Grain Size ◽  
Austenite Grain

scholarly journals Effect of Initial Microstructure on the Toughness of Coarse-Grained Heat-Affected Zone in a Microalloyed Steel

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4760
Author(s):  
Minghao Shi ◽  
Man Di ◽  
Jian Zhang ◽  
Rangasayee Kannan ◽  
Jing Li ◽  
...  
Keyword(s):  
Grain Size ◽  
Base Metal ◽  
Thermal Cycle ◽  
Microalloyed Steel ◽  
Charpy Impact ◽  
Coarse Grained ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Prior Austenite Grain Size ◽  
Prior Austenite Grain

Toughness of the coarse-grained-heat-affected-zone (CGHAZ) strongly depends on the prior austenite grain size. The prior austenite grain size is affected not only by chemical composition, thermal cycle, and dissolution of second-phase particles, but also by the initial microstructure. The effect of base metal microstructure (ferrite/pearlite obtained by air cooling and martensite obtained by water-quenching) on Charpy impact toughness of the CGHAZ has been investigated for different heat inputs for high-heat input welding of a microalloyed steel. A welding thermal cycle with a heat input of 100 kJ/cm and 400 kJ/cm were simulated on the MMS-300 system. Despite a similar microstructure in the CGHAZ of both the base metals, the average Charpy impact energy for the air-cooled base metal was found to be higher than the water-quenched base metal. Through thermo-kinetic simulations, it was found that a higher enrichment of Mn/C at the ferrite/austenite transformation interface of the CGHAZ of water-quenched base metal resulted in stabilizing austenite at a lower A1 temperature, which resulted in a coarser austenite grain size and eventually lowering the toughness of the CGHAZ.

Austenite grain size in the continuous casting process: Metallographic methods and evaluation

2008 ◽  
Vol 59 (6) ◽  
pp. 737-746 ◽  
Author(s):  
J. Reiter ◽  
C. Bernhard ◽  
H. Presslinger
Keyword(s):  
Grain Size ◽  
Continuous Casting ◽  
Casting Process ◽  
Continuous Casting Process ◽  
Austenite Grain Size ◽  
Austenite Grain

Effect of austenite grain size on isothermal bainite transformation in low carbon microalloyed steel

2011 ◽  
Vol 27 (11) ◽  
pp. 1657-1663 ◽  
Author(s):  
L Y Lan ◽  
C L Qiu ◽  
D W Zhao ◽  
X H Gao ◽  
L X Du
Keyword(s):  
Grain Size ◽  
Microalloyed Steel ◽  
Low Carbon ◽  
Bainite Transformation ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Carbon Microalloyed

Austenite Grain Size of Thin Slab and Its Influence on Direct Hot Strip Rolling of Nb Microalloyed Steel

2005 ◽  
Vol 500-501 ◽  
pp. 295-302 ◽  
Author(s):  
Hong Tao Zhang ◽  
Ganyun Pang ◽  
Rui Zhen Wang ◽  
Chengbin Liu
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Microalloyed Steel ◽  
Thin Slab ◽  
Hot Strip Rolling ◽  
Austenite Grain Size ◽  
Thick Slab ◽  
Rolling Pass ◽  
Austenite Grain ◽  
Nb Microalloyed Steel

In the production with thin slab casting a serious problem of insufficient grain refinement and microstructural inhomogeneity has been found. In this paper attention has been paid to the austenite grain size changes in thin slab of a high strength Nb microalloyed steel under as-cast conditions and after first rolling pass. For comparison, the conventional thick slab was also investigated. It was found that although as-cast thin slab shows a smaller average austenite grain size than that of as cast thick slab; the latter after reheating shows a much finer average austenite grain size. The first rolling pass at high temperature and with heavy reduction causes rapid recrystallization that contributes to austenite grain refinement.

The Microstructure Evolution of Nb, Ti Complex Microalloyed Steel during the CSP Process

2005 ◽  
Vol 500-501 ◽  
pp. 229-236 ◽  
Author(s):  
Rui Zhen Wang ◽  
C. Isaac Garcia ◽  
Ming Jian Hua ◽  
Hong Tao Zhang ◽  
Anthony J. DeArdo
Keyword(s):  
Grain Size ◽  
Size Range ◽  
Microalloyed Steel ◽  
Ferrite Matrix ◽  
Scattering Method ◽  
Cast Slab ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Three Samples ◽  
Hot Band

The development of microstructure of Nb,Ti-bearing microalloyed steel during the CSP process was studied. Three samples were taken from the as-cast slab prior to tunnel furnace, intermediate bar after stand F2 and the hot band, respectively. In the as-cast slab, the average austenite grain size is 654 µm with a large size range from 150 to 2000 µm. In the intermediate bar after stand F2, the austenite grains are remarkably refined, but are heterogenous due to the incomplete recrystallization, which are in the size range of 23 to 116 µm. In the hot band is mainly non-polygonal ferrite. Microstructural heterogeneity exists in the hot band. It is attributed to the heterogeneous austenite grain size in the intermediate bar and the less rolling reduction after stand F2. With regards to precipitation, cubic TiN and fine precipitates less than 20nm are commonly observed in the as-cast slab and the intermediate bar. Some complex (Ti,Nb)(C,N) precipitates with a slightly larger size also exist. In the hot band, most particles are complex (Ti,Nb)(C,N) precipitates, in a shape of irregular or cruciform. The fine precipitates which can strengthen the ferrite matrix are seldom seen. These results are in good agreement with the size distribution of the precipitates determined using small angle X-ray scattering method. The chemical phase analysis reveals that 45%Nb of the total and 43%Ti of the total are still in solution in ferrite of the hot band.

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