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.

"In Situ-Tracking” Observation of Stainless Steel Microstructural Development during Elevated Service Using EBSD and SEM

2007 ◽  
Vol 561-565 ◽  
pp. 2087-2090 ◽  
Author(s):  
Ya Ming Huang ◽  
Qiang Fu ◽  
Chun Xu Pan
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Electron Backscatter Diffraction ◽  
Microstructural Development ◽  
Dislocation Model ◽  
Recrystallization Process ◽  
Novel Technique ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Electron backscatter diffraction (EBSD) has been developed as a novel technique for characterizing crystallographic textures in recent years. The present paper proposes an “in-situ-tracking” approach using SEM and EBSD to examining the microstructural development and grain boundary variation of stainless steel during elevated 1200 °C service. The results revealed that in addition to the coarsened grains the fraction of low angle grain boundaries (LABG) became increased and flattened obviously during service. Comparing to the regular high temperature service (below 900 °C), the present “recovery and recrystallization” process was accelerated due to dislocation fastened movement and intensive interaction. However, the grain growth mechanism still meet the well-accepted dislocation model of subgrain combination.

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.

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.

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