Effect of Hot Deformation Temperature on the Restoration Mechanisms and Texture in a High-Cr Ferritic Stainless Steel

2013 ◽  
Vol 762 ◽  
pp. 705-710 ◽  
Author(s):  
Saara Mehtonen ◽  
L. Pentti Karjalainen ◽  
David A. Porter
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Hot Deformation ◽  
Deformation Temperature ◽  
Electron Backscatter Diffraction ◽  
Shear Bands ◽  
Compression Tests ◽  
Recrystallized Grain Size ◽  
Evolution Of Microstructure ◽  
Backscatter Diffraction

The effect of hot deformation temperature on the deformed microstructures and evolution of microstructure and texture of a 21Cr Ti-Nb dual-stabilized ferritic stainless steel was studied using plane strain hot compression tests on a Gleeble 1500 thermomechanical simulator. The deformation was carried out at 550 - 950 °C with a strain of 0.5 at 1 s-1. The compression was followed by fast cooling to room temperature in order to study the deformed microstructures. Some specimens were heated from the deformation stage to either 750 or 950 °C and held for 0 or 30 s in order to study the nucleation process of recrystallization. The electron backscatter diffraction technique was used to analyze the resultant microstructures and textures. Lowering of the deformation temperature increased the rate of static recrystallization (SRX) and decreased the recrystallized grain size. After deformation at 550 and 600 °C and complete SRX, beneficial γ-fibre texture formed presumably as a result of nucleation at in-grain shear bands. SRX after deformation at 750 °C or above led to the formation of harmful α-fibre textures with weak γ-fibre.

Grains and Sub Grains Identification in AISI 430 Stainless Steel with Atomic and Magnetic Force Microscopies

2005 ◽  
Vol 11 (S03) ◽  
pp. 150-153 ◽  
Author(s):  
J. M. C. Vilela ◽  
N. J. L. de Oliveira ◽  
M. L. Talarico ◽  
M. S. Andrade ◽  
R. A. N. M. Barbosa ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Magnetic Force ◽  
Electron Backscatter Diffraction ◽  
Polarized Light ◽  
Force Microscopy ◽  
430 Stainless Steel ◽  
Anisotropic Plastic ◽  
Backscatter Diffraction ◽  
Aisi 430

Cold rolled sheets of AISI 430 ferritic stainless steel have been widely used in kitchen utensils, ornamental articles, among other products due to their corrosion resistance and good formability. However, a localized increase of the surface roughness, known as ridging, develops during ferritic stainless steel forming [1]. The ridging is caused by anisotropic plastic flow of the material containing alternated bands of different crystallographic textures. These bands, or grain colonies, are formed during hot rolling fabrication step. During this step, the deformed grains can undergo dynamic recrystallization and/or recovery. In the regions where recovery takes place these texture bands are formed. In order to study ridging, it is necessary to identify the recovered regions (regions containing sub grains with nearly the same crystal orientation) and recrystallized regions (regions containing grains with different crystal orientations). Two well established techniques are applied to the characterization of recrystallized and recovered grains: the optical microscopy with polarized light, normally done in samples prepared with colored etching, and the electron backscatter diffraction (EBSD). In this work, atomic force microscopy (AFM) and magnetic force microscopy (MFM) were used to study the recrystallization and the recovery of the deformed specimens.

scholarly journals Microstructure Evolution During Hot Deformation of REX734 Austenitic Stainless Steel

2019 ◽  
Vol 51 (2) ◽  
pp. 845-854 ◽  
Author(s):  
Mykola Kulakov ◽  
Jianglin Huang ◽  
Michail Ntovas ◽  
Shanmukha Moturu
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Electron Backscatter Diffraction ◽  
Compression Testing ◽  
Recrystallization Process ◽  
Twin Boundaries ◽  
Wide Range ◽  
Evolution Of Microstructure ◽  
Backscatter Diffraction

AbstractMechanical properties of a REX734 austenitic stainless steel were examined through compression testing over a wide range of temperatures (1173 K to 1373 K (900 °C to 1100 °C)) and strain rates (0.1 to 40 s−1) that cover deformation conditions encountered in different metalworking processes. The evolution of microstructure was studied using electron microscopy combined with electron backscatter diffraction and energy-dispersive spectroscopy. Partially recrystallized microstructures were obtained after compression testing at 1173 K (900 °C), while after deformation at 1273 K and 1373 K (1000 °C and 1100 °C), the material was fully recrystallized almost in all examined cases. The role of dynamic and metadynamic restoration processes in the formation of final microstructure was investigated. Σ3 twin boundaries lost their twin character and transformed into general high-angle grain boundaries as a result of deformation, while during recrystallization new Σ3 twin boundaries formed. The evolution of precipitates during compression testing and their role in the recrystallization process was also discussed.

Analysis of Chemical Changes and Microstructure Characterization during Deformation in Ferritic Stainless Steel

2013 ◽  
Vol 19 (4) ◽  
pp. 959-968 ◽  
Author(s):  
Andrés Núñez ◽  
Xavier Llovet ◽  
Juan F. Almagro
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Electron Backscatter Diffraction ◽  
Biaxial Tension ◽  
Annealing Treatment ◽  
Chemical Compositions ◽  
Backscatter Electron Imaging ◽  
Electron Imaging ◽  
Deformation Tests ◽  
Backscatter Diffraction

AbstractUni- and biaxial tension deformation tests, with different degrees of deformation, have been done on AISI 430 (EN 1.4016) ferritic stainless steel samples, which had both different chemical compositions and had undergone different annealing treatments. The initial and deformed materials were characterized by using electron backscatter diffraction and backscatter electron imaging in a scanning electron microscope together with electron probe microanalysis. The correlation observed among the chemical compositions, annealing treatment, and strain level obtained after deformation is discussed.

Recrystallization of Coarse-Grained Nb-Containing AISI-430 Ferritic Stainless Steel

2010 ◽  
Vol 638-642 ◽  
pp. 3009-3014 ◽  
Author(s):  
Rodrigo P. Siqueira ◽  
Hugo Ricardo Zschommler Sandim ◽  
Tarcisio R. Oliveira
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Electron Backscatter Diffraction ◽  
Secondary Recrystallization ◽  
Coarse Grained ◽  
Ferritic Stainless Steels ◽  
Coarse Grains ◽  
Cold Rolled ◽  
Backscatter Diffraction ◽  
Aisi 430

Ferritic stainless steels (FSSs) have excellent corrosion resistance and good mechanical properties. Applications include heaters, houseware, and automotive exhaust systems. Alloying, even in small amounts, affects the recrystallization behavior of FSSs by selective dragging or pinning effects. In the present study, we present the main results regarding the recrystallization of a coarse-grained Nb-containing AISI 430 ferritic stainless steel. The material was processed by hot rolling and further annealed at 1250oC for 2 h to promote secondary recrystallization. Following, the material was cold rolled to a 80% reduction in thickness and annealed at 400-1000oC for 15 min. Scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) were used to characterize the microstructure. Recrystallization of this steel begins at 700oC. Important orientation effects were observed in both as-rolled and annealed conditions. Recrystallization kinetics was strongly dependent on the initial orientation of the coarse grains. Results show that grain boundaries, transition bands and coarse Nb(C,N) particles are preferential sites for nucleation at moderate annealing temperatures.

Texture development in 304LN austenitic stainless steel during post-hot-axisymmetric compression

2020 ◽  
pp. 095440542097803
Author(s):  
Matruprasad Rout ◽  
Shiv Brat Singh ◽  
Surjya K Pal
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Hot Deformation ◽  
Deformation Temperature ◽  
Texture Evolution ◽  
Isothermal Holding ◽  
Holding Time ◽  
Effect Of Temperature ◽  
Diffraction Effect ◽  
Compression Tests

In the present work, 304LN austenitic stainless steel has been considered for the texture evolution study after the hot-deformation process. The axi-symmetric compression tests, with post-deformation isothermal holding at the same temperature, were performed at 900°C, 1000°C and 1100°C with a strain rate of 0.1 s−1. Texture evolution during the post-hot-deformation was studied through electron back scattered diffraction. Effect of temperature and holding time on texture evolution were studied. At low deformation temperature and lesser holding time 〈100〉 and 〈110〉 fibre textures were observed. At high deformation temperature and/or high holding time the texture becomes random. Texture intensity along α fibre, for all the temperatures, is chaotic whereas along β and τ fibres it is uniform at low temperature and becomes chaotic with the increase in deformation temperature. Goss component was found to be a major texture component with significant amount of ND and RD rotated cube components.

scholarly journals Effect of Microstructure on Chip Formation during Machining of Super Austenitic Stainless Steel

2017 ◽  
Vol 4 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Mohanad Alabdullah ◽  
Ashwin Polishetty ◽  
Junior Nomani ◽  
Guy Littlefair
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Electron Backscatter Diffraction ◽  
Shear Bands ◽  
Chip Morphology ◽  
Machining Process ◽  
On Chip ◽  
Corrosive Environments ◽  
Backscatter Diffraction ◽  
Super Austenitic Stainless Steel

The AL6XN Super Austenitic Stainless Steel alloy is a commonly used steel in corrosive environments and tough applications. This paper aims to investigate the execution of a machining process on the AL6XN alloy. A wet machining process has been executed to machine the alloy under a combination of various cutting conditions using an up milling approach. Two cutting speeds, two cutting depths and two feeds were used. The outputs obtained and listed in this paper are the microstructure analysis, surface microhardness and the chip morphology. The microstructure of the AL6XN alloy was revealed using Electron Microscope and Electron Backscatter Diffraction (EBSD). Work hardening layer was located in the subsurface of the machined alloy. EBSD data assured that no phase transformation was occurred within the deformed microstructure due to machining. The chip cross-section was revealed to identify the presence of the shear bands and to calculate the alloy serration degree.

Characteristics of the Deformed and Recrystallised Grains Obtained after Hot Plane Strain Compression of a Model Fe-30wt%Ni Alloy

2004 ◽  
Vol 467-470 ◽  
pp. 21-26 ◽  
Author(s):  
F. Bai ◽  
P. Cizek ◽  
Eric J. Palmiere ◽  
Mark W. Rainforth
Keyword(s):  
Plane Strain ◽  
Crystallographic Texture ◽  
Hot Deformation ◽  
Electron Backscatter Diffraction ◽  
Orientation Dependence ◽  
Plane Strain Compression ◽  
Formation Mechanisms ◽  
Subgrain Structure ◽  
Compression Tests ◽  
Texture Characteristics

The development of physically-based models of microstructural evolution during hot deformation of metallic materials requires knowledge of the grain/subgrain structure and crystallographic texture characteristics over a range of processing conditions. A Fe-30wt%Ni based alloy, retaining a stable austenitic structure at room temperature, was used for modelling the development of austenite microstructure during hot deformation of conventional carbon-manganese steels. A series of plane strain compression tests was carried out at a temperature of 950 °C and strain rates of 10 s-1 and 0.1 s-1 to several strain levels. Evolution of the grain/subgrain structure and crystallographic texture was characterised in detail using quantitative light microscopy and highresolution electron backscatter diffraction. Crystallographic texture characteristics were determined separately for the observed deformed and recrystallised grains. The subgrain geometry and dimensions together with the misorientation vectors across sub-boundaries were quantified in detail across large sample areas and the orientation dependence of these characteristics was determined. Formation mechanisms of the recrystallised grains were established in relation to the deformation microstructure.

Comparison of Workability of ZK60A Alloy Depending on Casting Methods

2012 ◽  
Vol 630 ◽  
pp. 35-40
Author(s):  
K.H. Jung ◽  
B. Ahn ◽  
S. Lee ◽  
D.S. Choi ◽  
Y.S. Lee ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Continuous Casting ◽  
Elevated Temperatures ◽  
Electron Backscatter Diffraction ◽  
Die Casting ◽  
Inspection System ◽  
Compression Tests ◽  
X Ray ◽  
Electron Backscatter ◽  
Backscatter Diffraction

In this research, the effect of casting methods on the workability of magnesium alloy ZK60A was investigated by comparing two different billets, fabricated by semi-continuous casting and die casting. To determine the workability of the materials, uniaxial compression tests were conducted at different elevated temperatures and strain rate of 0.01/s. In addition, the X-ray inspection system and electron backscatter diffraction (EBSD) were employed to compare their internal defects and microstructures, respectively. The workability of ZK60A depending on the casting methods is discussed based on the obtained experimental results.

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