Study on the Microstructure of 20 Steel With Strain Aging

2011 ◽  
Author(s):  
Mengli Li ◽  
Weiqiang Wang ◽  
Aiju Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Microscopy ◽  
Strain Aging ◽  
Thick Wall ◽  
Transmission Electron ◽  
Stress Relieving ◽  
Micro Holes ◽  
Scanning Electron

20 steel thick-wall high-pressure pipes are widely used in chemical industry in China, but brittle fracture accidents of them happen frequently in recent years. The strain aging steel pipes in this research were artificially made in the laboratory and naturally occurred in fabrication or service. The microstructure of strain aging in samples taken from the unused pipes and the accident pipes caused directly or mainly by strain aging were observed with optical microscopy, scanning electron microscopy, and transmission electron microscopy. The results show that: (1)uniform ferrite and pearlite with uniform lamellar structure can be achieved with normalizing; lamellar pearlite fractures and distorts while a large number of dislocation cells, micro-holes or cracks appear in material after strain aging; and broken distorted pearlite changes to uniform spherical structure after stress relieving; (2) both the samples taken from unused and accident pipes which strain aging artificially in the laboratory and naturally in fabrication or service have the same characteristics as following: the basic changes of microstructure after strain aging cannot be observed with optical microscopy, but can be observed with scanning electron microscopy and transmission electron microscopy.

Digital imaging: When should one take the plunge?

1996 ◽  
Vol 54 ◽  
pp. 602-603
Author(s):  
John F. Mansfield
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Microscopy ◽  
Digital Imaging ◽  
Storage Devices ◽  
Major Benefit ◽  
Transmission Electron ◽  
New Instrument ◽  
Scanning Electron

The current imaging trend in optical microscopy, scanning electron microscopy (SEM) or transmission electron microscopy (TEM) is to record all data digitally. Most manufacturers currently market digital acquisition systems with their microscope packages. The advantages of digital acquisition include: almost instant viewing of the data as a high-quaity positive image (a major benefit when compared to TEM images recorded onto film, where one must wait until after the microscope session to develop the images); the ability to readily quantify features in the images and measure intensities; and extremely compact storage (removable 5.25” storage devices which now can hold up to several gigabytes of data).The problem for many researchers, however, is that they have perfectly serviceable microscopes that they routinely use that have no digital imaging capabilities with little hope of purchasing a new instrument.

scholarly journals Digital Imaging: When Should One Take The Plunge?

1997 ◽  
Vol 5 (4) ◽  
pp. 14-15
Author(s):  
John F. Mansfield
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Microscopy ◽  
Digital Imaging ◽  
High Quality ◽  
Storage Devices ◽  
Major Benefit ◽  
Transmission Electron ◽  
Scanning Electron

The current imaging trend in optical microscopy, scanning electron microscopy (SEM) or transmission electron microscopy (TEM) is to record all data digitally. Most manufacturers currently market digital acquisition systems with their microscope packages. The advantages of digital acquisition include: almost instant viewing of the data as a high-quality positive image (a major benefit when compared to TEM images recorded onto film, where one must wait until after the microscope session to develop the images); the ability to readily quantify features in the images and measure intensities; and extremely compact storage (removable 5.25” storage devices which now can hold up to several gigabytes of data).

Effects of Plate Magnetic Field on Iron-Rich Phase of Al-20Si-10Fe Alloy during Solidification

2012 ◽  
Vol 182-183 ◽  
pp. 167-173
Author(s):  
Ming Li ◽  
Zhi Ming Shi ◽  
Dong Fang
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Optical Microscopy ◽  
Energy Dispersive Spectrum ◽  
Rich Phase ◽  
Transmission Electron ◽  
Scanning Electron

This paper studies iron-rich phase transformation law and mechanism of Al-20Si-10Fe alloy under the effect of plate magnetic field. with optical microscopy(OM)，scanning electron microscopy(SEM),energy dispersive spectrum(EDS)and transmission electron microscopy(TEM). The results show that plate magnetic field is directly involved in the phase transformation of iron-rich phase, making iron-rich phase change from lath-shaped β-Al5FeSi to herringbone-shapedα-Al8SiFe2. The enforcement of plate magnetic field during the phase-transforming process of β-Al5FeSi→α-Al8Si Fe2makes block α-Al1.3Si7.8Fe2.1phase yield out. And precipitation of α-Al1.3Si7.8Fe2.1phase is affected by the transforming process ofβ-Al5SiFe phase→α-Al8Si Fe2phase.

Friction Stir Welding of Precipitation Hardened Ni Based Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 3763-3768 ◽  
Author(s):  
Hyun J. Jun ◽  
Raghavan Ayer ◽  
Thirumalai Neeraj ◽  
Russell Steel
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Friction Stir Welding ◽  
Optical Microscopy ◽  
Grain Structure ◽  
Friction Stir ◽  
Transmission Electron ◽  
The Relationship ◽  
Scanning Electron

Commercial Waspaloy plates with two different initial microstructures (annealed and aged) were joined by Friction Stir Welding (FSW). This study presents the evolution of the grain structure, and precipitation, dissolution and reprecipitation of the γ' phase during FSW using Optical Microscopy, Scanning Electron Microscopy and Transmission Electron Microscopy. The relationship between microstructure and microhardness is also discussed.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Comparative Study of the Fine Morphology of Sensory Receptors in Aspidogaster conchicola and Cotylaspis insignis

1972 ◽  
Vol 30 ◽  
pp. 150-151
Author(s):  
Venita F. Allison ◽  
J. E. Ubelaker ◽  
J. H. Martin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nervous System ◽  
Osmic Acid ◽  
Sensory Receptors ◽  
Transmission Electron ◽  
Sensory Structures ◽  
Fine Morphology ◽  
Scanning Electron

It has been suggested that parasitism results in a reduction of sensory structures which concomitantly reflects a reduction in the complexity of the nervous system. The present study tests this hypothesis by examining the fine morphology and the distribution of sensory receptors for two species of aspidogastrid trematodes by transmission and scanning electron microscopy. The species chosen are an ectoparasite, Cotylaspis insignis and an endoparasite, Aspidogaster conchicola.Aspidogaster conchicola and Cotylaspis insignis were obtained from natural infections of clams, Anodonta corpulenta and Proptera purpurata. The specimens were fixed for transmission electron microscopy in phosphate buffered paraformaldehyde followed by osmic acid in the same buffer, dehydrated in an ascending series of ethanol solutions and embedded in Epon 812.

Anisotropic Membranes as Substrates for Sem

1976 ◽  
Vol 34 ◽  
pp. 444-445
Author(s):  
Thomas P. Turnbull ◽  
W. F. Bowers
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Flow ◽  
Polymer Chemistry ◽  
Surface Porosity ◽  
Transmission Electron ◽  
Pore Texture ◽  
Spongy Layer ◽  
Scanning Electron

Until recently the prime purposes of filters have been to produce clear filtrates or to collect particles from solution and then remove the filter medium and examine the particles by transmission electron microscopy. These filters have not had the best characteristics for scanning electron microscopy due to the size of the pores or the surface topography. Advances in polymer chemistry and membrane technology resulted in membranes whose characteristics make them versatile substrates for many scanning electron microscope applications. These polysulphone type membranes are anisotropic, consisting of a very thin (0.1 to 1.5 μm) dense skin of extremely fine, controlled pore texture upon a much thicker (50 to 250μm), spongy layer of the same polymer. Apparent pore diameters can be controlled in the range of 10 to 40 A. The high flow ultrafilters which we are describing have a surface porosity in the range of 15 to 25 angstrom units (0.0015-0.0025μm).

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