scholarly journals Microstructure evaluation of UNS S32205 duplex stainless steel friction stir welds

2013 ◽  
Vol 66 (2) ◽  
pp. 187-191 ◽  
Author(s):  
Tiago F. A. Santos ◽  
Ricardo R. Marinho ◽  
Marcelo T. P. Paes ◽  
Antonio J. Ramirez
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Ferrite Matrix ◽  
Optical Scanning ◽  
Friction Stir ◽  
Microstructure Evaluation ◽  
Transmission Electron ◽  
Steel Welds

UNS S32205 duplex stainless steel welds were performed by friction stir welding (FSW). Advancing and retreating sides showed distinct characteristics in the welded joint. The advancing side shows the strongest grain refinement which is corroborated by microhardness measurements. The microstructure characterization was carried out by optical, scanning and transmission electron microscopy. The thermomechanically affected zone displays austenite islands deformed in a ferrite matrix. The stir zone (SZ) showed a fine recrystallized microstructure providing an outstanding increase of hardness associated with better corrosion performance. Transmission electron microscopy and corrosion tests have corroborated the absence of intermetallic phases on welded joints.

Dislocations and stacking faults in stainless steel

1957 ◽  
Vol 240 (1223) ◽  
pp. 524-538 ◽  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stainless Steel ◽  
Grain Boundaries ◽  
Stacking Faults ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Thin Sections ◽  
Partial Dislocations ◽  
Transmission Electron

Further experiments by transmission electron microscopy on thin sections of stainless steel deformed by small amounts have enabled extended dislocations to be observed directly. The arrangement and motion of whole and partial dislocations have been followed in detail. Many of the dislocations are found to have piled up against grain boundaries. Other observations include the formation of wide stacking faults, the interaction of dislocations with twin boundaries, and the formation of dislocations at thin edges of the foils. An estimate is made of the stacking-fault energy from a consideration of the stresses present, and the properties of the dislocations are found to be in agreement with those expected from a metal of low stacking-fault energy.

Microstructure, Texture, Mechanical and Corrosion Performance of the Stainless Duplex Steel UNS S32205 Submitted to Warm Rolling

2018 ◽  
Vol 941 ◽  
pp. 118-123
Author(s):  
Dagoberto Brandão Santos ◽  
Raphael França Assumpção ◽  
Daniela Barçante Perasoli ◽  
Dalila Chaves Sicupira
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Warm Rolling ◽  
Optical Scanning ◽  
Transmission Electron ◽  
Duplex Steel ◽  
Hot Rolled ◽  
Chlorine Ion

The UNS S32205 duplex stainless steel was warm rolled at 600°C with 60 and 80% of thickness reduction. The microstructure was characterized by optical, scanning and transmission electron microscopy, X-ray diffractometry and EBSD. The corrosion resistance was evaluated by electrochemical behavior in the chlorine ion environment using potentiodynamic polarization measurements. The tensile strength reached 1185 MPa and 1328 MPa, after warm rolling with 60 and 80%, respectively. In steel as-supplied, hot rolled and annealed, the tensile strength was 774 MPa. Ferrite microtexture presented the α-fiber and the rotated cube component, while the austenite enhanced the brass, copper, and cube components to a lesser extent. The substructure was characterized by intense formation of tangles and forests of dislocations and discrete subgrains in the ferritic phase and by planar gliding of dislocations and formation of dense dislocations walls in the austenite. Despite the existence of a certain similarity among the values of pitting potentials obtained for all samples, the number of pits observed was higher in the as-received sample, followed by the samples with 60 and 80% reduction. These results draw attention to innovative routes in the industrial production of duplex stainless steel of this class, even considering ductility lost. Keywords: Warm rolling; Mechanical strength; Texture; Substructure; Corrosion resistance

Transmission Electron Microscopy of Corrosion of Stainless Steel-Zirconium Metal Waste Forms

1999 ◽  
Vol 5 (S2) ◽  
pp. 848-849
Author(s):  
J.S. Luo ◽  
D.P. Abraham
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stainless Steel ◽  
Corrosion Behavior ◽  
Spent Nuclear Fuel ◽  
Intermetallic Phase ◽  
Fission Products ◽  
Microstructural Characterization ◽  
Waste Forms ◽  
Transmission Electron

Stainless steel-zirconium (SS-Zr) alloys have been developed as waste forms to immobilize and retain fission products generated during the electrometallurgical treatment of spent nuclear fuel. The baseline waste form is a stainless steel-15 wt.% zirconium (SS-15Zr) alloy, which is prepared by melting appropriate amount of Type 316 stainless steel (SS316) and high purity zirconium. As zirconium has very low solubility in iron, the addition of zirconium to SS316 results in the formation of ZrFe2 -type Laves intermetallic phases. The corrosion behavior of stainless steel has been widely studied; however, the corrosion behavior of the Zr-based-intermetallic has not been previously investigated. In this paper, we present a microstructural characterization of the corrosion layer formed on the Zr-intermetallic phase using energy-filtering transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDS).Specimens of SS-15Zr alloy, crushed to 75 to 150 μm sizes, were immersed in 90°C deionized water for a period of two years.

Hydrogen induced plastic deformation of stainless steel

1998 ◽  
Vol 513 ◽  
Author(s):  
V. J. Gadgil ◽  
E. G. Keima ◽  
H. J. M. Geijselaers
Keyword(s):  
Electron Microscopy ◽  
Finite Element Method ◽  
Transmission Electron Microscopy ◽  
Computer Simulation ◽  
Plastic Deformation ◽  
Stainless Steel ◽  
Cross Section ◽  
Dislocation Substructure ◽  
Transmission Electron ◽  
Aqueous Environments

ABSTRACTHydrogen can influence the behaviour of materials significantly. The effects of hydrogen are specially pronounced in high fugacities of hydrogen which can occur at the surface of steels in contact with certain aqueous environments. In this investigation the effect of high fugacity hydrogen on the surface of stainless steel was investigated using electrochemical cathodic charging. Microhardness was measured on the cross section. Transmission electron microscopy was used to investigate the dislocation substructure just below the surface. Computer simulation using finite element method was carried out to estimate the extent and severity of the deformation. The significance of the results are discussed in relation to the loss of ductility due to hydrogen.

Microstructure and Indentation Fracture of Dysprosium Niobate

2005 ◽  
Vol 20 (6) ◽  
pp. 1422-1427 ◽  
Author(s):  
Byong-Taek Lee ◽  
Waltraud M. Kriven
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Plastic Deformation ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Indentation Fracture ◽  
Optical Scanning ◽  
Periodic Arrays ◽  
Transmission Electron ◽  
Hot Hardness

The high-temperature indentation fracture and microstructures of dysprosium niobate (DyNbO4) were investigated by optical, scanning, and transmission electron microscopy (OM, SEM, and TEM). Polycrystalline samples were sintered at 1350 °C for 3 h and cut into 3 mm disks for TEM. The disks were indented in a Nikon QM (Tokyo, Japan) hot hardness indenter at room temperature up to 1000 °C. Many lamellar twins having different widths were observed by TEM as well as intergranular microcracks. The room temperature hardness was relatively low at 5.64 GPa and decreased with elevated temperatures. Crack lengths were short, showing a typical micro-cracking effect. In the sample indented at 1000 °C, dislocations in periodic arrays were evident, and their density increased markedly due to heavy plastic deformation.

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