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.

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.

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.

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

Recrystallization and Grain Growth Behavior of few Low Carbon Steels after Severe Cold Rolling and Annealing

2013 ◽  
Vol 753 ◽  
pp. 201-206
Author(s):  
Ranjit K. Ray ◽  
Rajib Saha
Keyword(s):  
Cold Rolling ◽  
Grain Growth ◽  
Systematic Investigation ◽  
Carbon Steels ◽  
Growth Behavior ◽  
Interstitial Free ◽  
Low Carbon ◽  
Cold Rolled ◽  
Grain Growth Behavior ◽  
Very High

Less attention has been paid to study the recrystallization and grain growth behavior of severe plastically deformed (SPD) metals specially steels that are deformed to very high strain by conventional rolling method. Present work has been focused on systematic investigation of recrystallization and grain growth behavior of a Aluminium Killed (AK), an Interstitial Free (IF) and an Interstitial Free High Strength (IFHS) steels that were subjected to very high levels of strain (ԑeqv= 4.51) by cold rolling. The cold rolled steels show fine lamellar structure with very strong texture consists of both γ and α fibre. All the steels show formation of ultrafine grains and dramatic rise in the intensity of α fibre component in the early stages of annealing. However, progress of annealing for longer time leads to an increase in the mean grain size as well as γ fibre intensity. The results also indicate that the heavily cold rolled material exhibit selective growth of specific texture components.It appears that microstructure and texture is closely related to the observed phenomenon.

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