Cold Rolled Microstructure and Its Evolution during Recovery and First Recrystallisation Stages in Low Carbon Steels

2004 ◽  
Vol 467-470 ◽  
pp. 241-246 ◽  
Author(s):  
M. Díaz-Fuentes ◽  
E. Novillo ◽  
Amaia Iza-Mendia ◽  
Isabel Gutiérrez
Keyword(s):  
Deformation Texture ◽  
Carbon Steels ◽  
Subgrain Structure ◽  
Processing Conditions ◽  
Low Carbon ◽  
Electron Backscattered Diffraction ◽  
Steel Sheets ◽  
Deformation Banding ◽  
Different Temperatures ◽  
Cold Rolled

During annealing of cold rolled steel sheets, the evolution of the texture, to produce the characteristic texture of a recrystallised material, depends on a series of factors, including the starting deformation texture, composition and processing conditions. In the present work, electron backscattered diffraction (EBSD) techniques have been used to investigate the deformation substructures being developed by cold rolling into grains belonging to different texture components. The strain localisation, the deformation banding, the spread in orientation into grains with different orientations are some of the aspects that have been considered. Annealing cycles at different temperatures have also been carried out in order to promote recovery and initial stages of recrystallisation . The obtained substructures have been compared to the as-cold rolled ones. It has been observed that recovery induces the dislocation structures to arrange into subgrains. Associated to the ND fibre, a network of relatively high angle boundaries develop within the subgrain structure. The recrystallisation nuclei have been observed to evolve from such a network.

Recrystallization of Boron Containing and Boron-Free Low Carbon Steels Investigated by Thermoelectric Power and Hardness Measurements

2015 ◽  
Vol 812 ◽  
pp. 195-199
Author(s):  
András Mucsi ◽  
László Dévényi
Keyword(s):  
Thermoelectric Power ◽  
Carbon Steels ◽  
Low Carbon ◽  
Slow Cooling ◽  
Steel Sheets ◽  
Starting Point ◽  
Different Temperatures ◽  
Good Starting Point ◽  
Cold Rolled ◽  
Metallurgical Processes

The measurement of thermoelectric power is a powerful method to investigate the metallurgical processes occurring in steels. In this study, four low carbon cold rolled steel sheets having different composition were investigated. The cold rolled sheets were heated up at heating rate 20 °C/hour up to different temperatures, whilst the change of thermoelectric power and hardness have been measured at room temperature after slow cooling. The thermoelectric power of steels increases with temperature until the recrystallization finishes. The raise of thermoelectric power during recrystallization is ranging between 50 and 160 nV/K, depends on the composition of the sheet. Specimens consist of boron exhibit lower thermoelectric power after recrystallization than the steel without any boron, probably due to metastable borocarbide dissolution. This fact could be a good starting point to investigate the effect of boron on thermoelectric power of steels.

Laser-Ultrasonics as a Technique to Study Recrystallisation and Grain Growth

2004 ◽  
Vol 467-470 ◽  
pp. 1353-1362 ◽  
Author(s):  
Eva Lindh-Ulmgren ◽  
Mattias Ericsson ◽  
Dorota Artymowicz ◽  
W. Bevis Hutchinson
Keyword(s):  
Carbon Steels ◽  
Laser Ultrasonics ◽  
Continuous Annealing ◽  
Low Carbon ◽  
Steel Sheets ◽  
On Line ◽  
Cold Rolled ◽  
Dynamic Heating ◽  
Good Agreement

Laser-Ultrasonics (LUS) provides a means of obtaining microstructure information continuously and non-destructively both in the laboratory and for quality control on-line in industry. Ultrasound is both generated and recorded using lasers which permits remote, non-contact operation with fast sampling and also the capability of working at high temperatures or at moving surfaces, for example during industrial continuous annealing. Examples of dynamic heating trials will be presented for samples of cold rolled steel sheets where primary recrystallisation and ferrite austenite transformation are monitored in-situ as a function of temperature. Examples are also presented where the grain size of low carbon steels have been quantitatively analysed and show very good agreement with microscopy methods.

Grain Refinement by Rapid Transformation Annealing of Cold Rolled Low Carbon Steels

2005 ◽  
Vol 500-501 ◽  
pp. 771-778 ◽  
Author(s):  
P. Álvarez ◽  
C. Lesch ◽  
Wolfgang Bleck ◽  
Hélène Petitgand ◽  
Joachim Schöttler ◽  
...  
Keyword(s):  
Grain Refinement ◽  
Rapid Heating ◽  
Carbon Steels ◽  
Low Carbon ◽  
Steel Sheets ◽  
Hsla Steels ◽  
Mn Content ◽  
Cold Rolled ◽  
Equiaxed Grains ◽  
Rapid Transformation

A novel thermal treatment, rapid transformation annealing (RTA), has been applied to six different cold rolled low-carbon (LC) steel sheets with the aim of refining their microstructure. The process involves rapid heating to just above the austenite (g) to ferrite (a) transformation temperature and subsequent rapid cooling to room temperature. Grain sizes around 2 µm in two different Nb-Ti HSLA steels, 5 µm in a Ti-LC steel and 6 µm in a plain LC (0.037%C) steel have been produced using fast cooling rates (200°C/s). Non-equiaxed structures are obtained in a Nb-Ti HSIF steel and in a plain LC (0.135%C) (CM) steel due to their higher Mn content. However, very fine equiaxed grains (2 µm) are obtained by rapid intercritical annealing (RIA) in the CM steel. Irrespective of the microalloying concept, the grain growth of recrystallized a grains before their transformation was inhibited in CM and in both HSLA steels. This inhibition is connected with the overlapping of a recrystallization and a-g transformation processes which is essential in order to achieve extreme grain refinement either by RTA or RIA.

scholarly journals Heat Treatment Effect on Lath Martensite

2018 ◽  
Vol 1 (1) ◽  
pp. 26-30
Author(s):  
Enikő Réka Fábián ◽  
Áron Kótai
Keyword(s):  
Heat Treatment ◽  
Lath Martensite ◽  
Carbon Steels ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
Heat Treated ◽  
Different Temperatures ◽  
Cold Rolled ◽  
Ice Water ◽  
Martensite Microstructure

Abstract During our investigation lath martensite was produced in low carbon steels by austenitization at 1200 °C/20 min, and the cooling of samples in ice water. The samples were tempered at a range of temperatures. The tempering effects on microstructure and on mechanical proprieties were investigated. Some samples with lath martensite microstructure were cold rolled and heat treated at different temperatures. Recrystallization was observed after heat treatment at 600-700 °C.

An EBSD Study on Orientation Effects during Recrystallization of Coarse-Grained Niobium

2004 ◽  
Vol 467-470 ◽  
pp. 519-524 ◽  
Author(s):  
Hugo Ricardo Zschommler Sandim ◽  
Dierk Raabe
Keyword(s):  
Longitudinal Section ◽  
Primary Recrystallization ◽  
Coarse Grained ◽  
Subgrain Structure ◽  
Electron Backscattered Diffraction ◽  
Subgrain Growth ◽  
Metallographic Inspection ◽  
Cold Rolled ◽  
Cold Worked ◽  
Viable Mechanism

The recrystallization behavior of coarse-grained niobium depends on the nature of its deformation microstructure. In this regard, a longitudinal section of a high-purity coarse-grained niobium ingot was cold rolled to a thickness reduction of 96% followed by annealing in vacuum at 800°C for 1 h. Metallographic inspection in cold-rolled and annealed specimens was carried out in a field emission gun scanning electron microscope (FEG-SEM). Microtexture was determined by electron-backscattered diffraction (EBSD) coupled to the FEG-SEM. The use this technique has evidenced details of the boundary character and subgrain structure found in partially recrystallized regions. The early stages of primary recrystallization are associated to the presence of high-angle lamellar boundaries found in the cold-worked state. Abnormal subgrain growth has been evidenced as a viable mechanism for nucleation of recrystallization.

scholarly journals Oriented Nucleation in Low-Carbon Steels

Texture ◽  
1974 ◽  
Vol 1 (3) ◽  
pp. 183-194 ◽  
Author(s):  
R. L. Every ◽  
M. Hatherly
Keyword(s):  
High Energy ◽  
Carbon Steels ◽  
Low Carbon ◽  
Line Broadening ◽  
Low Carbon Steels ◽  
X Ray ◽  
Cell Structures ◽  
Cold Rolled ◽  
Hot Rolled ◽  
Energy Components

The preferred orientations in hot-rolled, cold-rolled (70 % reduction), and annealed low-carbon steels (capped and aluminium-killed grades) have been investigated. Particular attention has been paid to the factors that control texture formation during annealing.The elastic energy stored in the cold-rolled steels is orientation dependent and the sequence, estimated from a Fourier analysis of X-ray line broadening, is V110>V111>V211>V100; the values range from 3.51 to 1.14 cal/g atom. The high energy components ({110}, {111}) have elongated cell structures but those of lower energy are equiaxed. In capped steels the high energy components recover and recrystallize most rapidly. In aluminium-killed steels both recovery and recrystallization are inhibited at low temperatures ≤ 500℃ and recrystallization begins first in the {111} components. It is shown that these effects are associated with precipitation and/or segregation of AlN during recovery. The recrystallization texture is determined primarily by oriented nucleation.

Conversion of Elongation Values for Cold-Rolled Low Carbon Steel Sheets

2005 ◽  
Vol 33 (2) ◽  
pp. 12585
Author(s):  
R Yebuah ◽  
M Tonkovic ◽  
S Kastelec
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Steel Sheets ◽  
Cold Rolled
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