Oriented Nucleation and Selective Growth during Secondary Recrystallization in Ultra Low Carbon Steels

2004 ◽  
Vol 467-470 ◽  
pp. 941-948 ◽  
Author(s):  
Kim Verbeken ◽  
Leo Kestens
Keyword(s):  
Grain Growth ◽  
Texture Evolution ◽  
Secondary Recrystallization ◽  
Low Carbon Steel ◽  
Primary Recrystallization ◽  
Carbon Steels ◽  
Abnormal Grain Growth ◽  
Selective Growth ◽  
Low Carbon ◽  
Ultra Low Carbon Steel

After primary recrystallization, on further annealing, abnormal grain growth occurred in ultra low carbon steel. Texture evolution was studied by comparing the orientations after complete secondary recrystallization, with on one hand the nuclei for abnormal grain growth and on the other hand the selective growth products of the primary recrystallized matrix. The influence of both mechanisms could be identified in the final texture.

Nucleation of Secondary Recrystallization in Ultra Low Carbon Steel

2005 ◽  
Vol 495-497 ◽  
pp. 1189-1194 ◽  
Author(s):  
Kim Verbeken ◽  
Leo Kestens
Keyword(s):  
Grain Boundaries ◽  
Grain Growth ◽  
Secondary Recrystallization ◽  
Low Carbon Steel ◽  
Abnormal Grain Growth ◽  
Low Carbon ◽  
Nucleation Stage ◽  
Ultra Low Carbon Steel ◽  
The Impact ◽  
Grain Coalescence

The nucleation stage of secondary recrystallization has never been considered in detail. During the present study, nucleation of abnormal grain growth in ULC steel was studied. A specific nucleation mechanism was identified. This mechanism involved the disappearance of low angle grain boundaries, which gave rise to the onset of a local grain coalescence mechanism that clusters grains that were only separated by low angle grain boundaries. The impact of the nucleation stage remained visible in the texture that was obtained after complete abnormal grain growth.

Surface Microstructure Evolution during Phase Transformation on Mn, Al and Si Alloyed Ultra Low Carbon Steel

2010 ◽  
Vol 297-301 ◽  
pp. 757-763
Author(s):  
Jai Gautam ◽  
Roumen H. Petrov ◽  
Elke Leunis ◽  
Leo Kestens
Keyword(s):  
Phase Transformation ◽  
Carbon Steel ◽  
Surface Texture ◽  
Texture Evolution ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Metal Vapour ◽  
Industrial Composition ◽  
Steel Sheets ◽  
Ultra Low Carbon Steel

This paper investigates the surface texture evolution after a short phase transformation annealing in low vacuum on ultra low carbon steel sheets alloyed with high Mn and Al and the cold rolled steel sheets of industrial composition alloyed with silicon. The ultra low carbon steel sheets with high Mn and Al show surface monolayer which has a characteristic surface texture components <100>//ND texture and microstructure with special grain morphology. Contrastingly, the industrial composition alloyed with silicon does not show specific surface texture components inspired by surface energy anisotropy at the surface. The composition depth profiling investigations performed on the all steel sheet surface shows that oxidation characteristics of alloying elements at the metal vapour interface have played a decisive influence on surface texture evolution. Further, transformation annealing in higher vacuum reveals that surface texture can be obtained in an industrial composition alloyed with silicon.

scholarly journals Effects of Double Reduction and Annealing on the Texture during Continuous Rolling of Ultrathin Sheets of Low Carbon Steels

2019 ◽  
Author(s):  
Laura G. Castruita-Avila ◽  
Francisco A. García-Pastor ◽  
Manuel de J. Castro-Roman ◽  
Jesus Emilio Camporredondo-Saucedo ◽  
Fabián Equihua-Guillen ◽  
...  
Keyword(s):  
Texture Evolution ◽  
Low Carbon Steel ◽  
Rolling Process ◽  
Carbon Steels ◽  
Low Carbon ◽  
Double Reduction ◽  
Process Stage ◽  
Texture Intensity ◽  
Pole Figures ◽  
Ebsd Technique

In this paper were analyzed the effects of double reduction and annealing during rolling process on texture evolution in an ultrathin sheet of low carbon steel. Experimental samples were obtained from each process stage. EBSD technique and correlated tools as orientation density functions and pole figures were used to analyze the microstructural changes and the texture. Results show that {111} recrystallized grains were formed during process, reducing dramatically gamma-fibre texture intensity and generating an adequate finished product for deep die stamping.

Change in Yield Strength of Nb-Bearing Ultra-Low Carbon Steels by Temper-Rolling

2018 ◽  
Vol 941 ◽  
pp. 230-235
Author(s):  
Ling Ling Yang ◽  
Tatsuya Nakagaito ◽  
Yoshimasa Funakawa ◽  
Katsumi Kojima
Keyword(s):  
Carbon Steel ◽  
Yield Strength ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Temper Rolling ◽  
Low Carbon ◽  
Solute Carbon ◽  
Ultra Low Carbon Steel ◽  
Dislocation Strengthening ◽  
Carbon Change

Yield strength of low carbon mild steel decreases when temper-rolling is applied to release yield point elongation. Generally mobile dislocation used to be considered as the cause of the YS lowering. However from Bailey-Hirsch theory, strength should be higher with temper-rolling because of the increase of dislocation density. To newly explain the lowering yield strength by temper-rolling, standing at the point that a few ppm carbon change Hall-Petch coefficient , decrease in yield strength by temper-rolling is investigated using an ultra-low carbon steel. Yield strength of steel with the small amount of solute carbon increased after 2% temper-rolling and didn’t change after aging. On the other hand, yield strength of steel with the high amount of solute carbon decreased after 2% temper-rolling and increased again after aging. Despite solute carbon content, the Hall-Petch σ0 increased by dislocation strengthening of temper-rolling. Hall-Petch coefficient ky of low solute carbon steel remained at the low level even after temper-rolling or aging , however, that of high solute carbon steels significantly decreased after temper-rolling and increased again after aging. Yield strength reduction of the high solute carbon steel can be attributed to the decrease of ky.

Surface Microstructure and Texture Evolution during Interrupted Annealing in Ultra Low Carbon Steels

2010 ◽  
Vol 89-91 ◽  
pp. 202-207
Author(s):  
J. Gautam ◽  
Roumen H. Petrov ◽  
Leo Kestens ◽  
Elke Leunis
Keyword(s):  
Phase Transformation ◽  
Surface Texture ◽  
Texture Evolution ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Control Surface ◽  
Surface Microstructure ◽  
Low Carbon ◽  
Metal Vapour ◽  
Low Carbon Steels

The austenite-to-ferrite phase transformation, which is an inherent feature of low-alloyed ultra low carbon steels, has scarcely been investigated to control surface texture and microstructure evolution. This paper investigates the systematic evolution of texture and microstructure at the metal-vapour interface during interrupted annealing in vacuum. Interrupted annealing experiments were carried out on three ultra low carbon steel sheets alloyed with Mn, Al and Si. The texture and microstructures have been investigated by X-ray diffraction and SEM-EBSD techniques. These results reveal a very clear variation in the surface texture components as well as in the surface microstructure after BCC recrystallisation and double  transformation interrupted annealing. The recrystallisation texture consists mainly of a <111>//ND fibre, while the transformation texture at the surface exhibits a <100>// ND fibre in combination with components of the <110> //ND fibre. It has been revealed that the latter specific surface texture was present in a monolayer of outer surface grains which were in direct contact with the vapour atmosphere. This observed phenomenon could be explained by considering the role of surface energy anisotropy occurring during phase transformation annealing.

Comparison of Deformation Structure of Lath Martensite in Low Carbon and Ultra-Low Carbon Steels

2007 ◽  
Vol 558-559 ◽  
pp. 933-938 ◽  
Author(s):  
S. Morito ◽  
T. Ohba ◽  
Tadashi Maki
Keyword(s):  
Carbon Steel ◽  
Cold Rolling ◽  
Lath Martensite ◽  
Low Carbon Steel ◽  
Carbon Steels ◽  
Microstructural Development ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
Ultra Low Carbon Steel ◽  
Dislocation Cells

The microstructural development of cold-rolled lath martensite structure in the low carbon steels and ultra-low carbon steels are studied and compared. In low carbon steel of as-quenched specimens, very thin austenite films exist at boundaries of adjacent laths, but do not exist in ultra-low carbon steel. After cold rolling for the low carbon steel, the lamellar dislocation cells, irregularly bent laths and kinked laths regions are frequently observed and, in some instances, the disappearance of initial lath boundaries is observed. The existence of retained austenite films suggests that the lath boundaries rarely disappear during cold-rolling in the low carbon steel.

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