scholarly journals An experimental study of the inclusion behavior during maraging steel processing

2019 ◽  
Vol 116 (5) ◽  
pp. 517
Author(s):  
Rayan Bhar ◽  
Julien Jourdan ◽  
Vincent Descotes ◽  
Alain Jardy
Keyword(s):  
Electron Beam ◽  
Maraging Steel ◽  
Sulfur Content ◽  
High Speed ◽  
Flow Direction ◽  
Marangoni Effect ◽  
Surface Active Element ◽  
Liquid Metal Surface ◽  
Steel Processing ◽  
Time Observation

Two maraging steel rods with different sulfur content, deliberately seeded with alumina (Al2O3) inclusions, were remelted in an electron beam furnace. The aim was on one hand to highlight the emergence of non-metallic inclusions at the liquid metal surface and on the other hand to study the effect of the presence of a surface active element (sulfur) on their behavior. The in situ real time observation of Al2O3 clusters was possible using both high-speed video and infrared thermography. The inclusions emerge and tend to collide and quickly agglomerate into rafts. A semi-quantitative analysis confirmed that almost 100% of inclusions are captured at the free surface. The electron beam creates large thermal gradients in the impingement zones; this induces thermocapillary convection (Marangoni effect). The flow direction depends on the sulfur content. This tendency was well-observed by following the trajectories of inclusion rafts.

Fundamental Research on the Mechanism of High-Speed Welding Undercut

2011 ◽  
Vol 287-290 ◽  
pp. 2152-2155 ◽  
Author(s):  
Peng Fei Huang ◽  
Chao Tang ◽  
Zhen Yang Lu
Keyword(s):  
Temperature Gradient ◽  
High Speed ◽  
Active Element ◽  
Flow Direction ◽  
Surface Flow ◽  
The Other ◽  
Welding Pool ◽  
Surface Active Element ◽  
Fundamental Research ◽  
Surface Active

Undercut is one of the most important problems which restrict welding speed. The research indicated that surface flow direction of welding pool near the periphery is the most important reason of undercut occurred. When the existence of surface active element (e.g. the content of S is about 0.02-0.04% in steel) change the sign of surface tension temperature coefficient to positive, undercut always occurs in TIG moveless welding, and not occurs when the content of S in iron is very low( e.g. S% is less 0.01%). Temperature gradient is the most important factor which influences the depth of undercut. The depth of undercut is bigger with the increase of temperature gradient when the other parameters are the same. When filling metal into welding pool, it restrained the molten metal movement from periphery to the pool center. So it can reduce the tendency of undercut, and eliminate undercut as increasing of filling metal ultimately.

Image quality vs data obtainment in biological electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 42-43
Author(s):  
J. E. Johnson
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Beam ◽  
Image Quality ◽  
High Speed ◽  
Early Period ◽  
Early Years ◽  
Fluorescent Screen ◽  
Embedding Medium

In the early years of biological electron microscopy, scientists had their hands full attempting to describe the cellular microcosm that was suddenly before them on the fluorescent screen. Mitochondria, Golgi, endoplasmic reticulum, and other myriad organelles were being examined, micrographed, and documented in the literature. A major problem of that early period was the development of methods to cut sections thin enough to study under the electron beam. A microtome designed in 1943 moved the specimen toward a rotary “Cyclone” knife revolving at 12,500 RPM, or 1000 times as fast as an ordinary microtome. It was claimed that no embedding medium was necessary or that soft embedding media could be used. Collecting the sections thus cut sounded a little precarious: “The 0.1 micron sections cut with the high speed knife fly out at a tangent and are dispersed in the air. They may be collected... on... screens held near the knife“.

MOTUNG 652

Alloy Digest ◽  
1957 ◽  
Vol 6 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Physical Properties ◽  
Tensile Properties ◽  
Sulfur Content ◽  
High Speed ◽  
High Speed Steel ◽  
Heat Treating ◽  
Bend Strength ◽  
Machining Properties

Abstract MOTUNG 652 is an intermediate molybdenum-tungsten type of high-speed steel conforming to the M-2 analysis. It is available with normal sulfur content or with high sulfur for free machining properties. This datasheet provides information on composition, physical properties, hardness, tensile properties, and compressive and bend strength as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-61. Producer or source: Cyclops Corporation.

HIGH SPEED ELECTRON BEAM THERAPY

1967 ◽  
Vol 99 (4) ◽  
pp. 932-938 ◽  
Author(s):  
A. ZUPPINGER
Keyword(s):  
Electron Beam ◽  
High Speed ◽  
Electron Beam Therapy

Electron-beam test system for high-speed devices

Scanning ◽  
1987 ◽  
Vol 9 (5) ◽  
pp. 201-204 ◽  
Author(s):  
M. Brunner ◽  
D. Winkler ◽  
R. Schmitt ◽  
B. Lischke
Keyword(s):  
Electron Beam ◽  
High Speed ◽  
Test System ◽  
Beam Test

Effect of Tube Diameter on Flow Phenomena of Gas-Liquid Two-Phase Flow in Microchannels

2015 ◽  
Author(s):  
Hideo Ide ◽  
Eiji Kinoshita ◽  
Ryo Kuroshima ◽  
Takeshi Ohtaka ◽  
Yuichi Shibata ◽  
...  
Keyword(s):  
Pressure Drop ◽  
High Speed ◽  
Water Solution ◽  
Flow Direction ◽  
Flow Characteristics ◽  
Tube Diameter ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Flow Phenomena ◽  
The Waves

Gas-liquid two-phase flows in minichannels and microchannels display a unique flow pattern called ring film flow, in which stable waves of relatively large amplitudes appear at seemingly regular intervals and propagate in the flow direction. In the present work, the velocity characteristics of gas slugs, ring films, and their features such as the gas slug length, flow phenomena and frictional pressure drop for nitrogen-distilled water and nitrogen-30 wt% ethanol water solution have been investigated experimentally. Four kinds of circular microchannels with diameters of 100 μm, 150 μm, 250 μm and 518 μm were used. The effects of tube diameter and physical properties, especially the surface tension and liquid viscosity, on the flow patterns, gas slug length and the two-phase frictional pressure drop have been investigated by using a high speed camera at 6,000 frames per second. The flow characteristics of gas slugs, liquid slugs and the waves of ring film are presented in this paper.

Application of High Speed Framing Camera in Debugging of High Current and Pulsed Electron Beam

2014 ◽  
Vol 51 (2) ◽  
pp. 022201
Author(s):  
江孝国 Jiang Xiaoguo ◽  
王远 Wang Yuan ◽  
代志勇 Dai Zhiyong ◽  
杨志勇 Yang Zhiyong ◽  
李洪 Li Hong ◽  
...  
Keyword(s):  
Electron Beam ◽  
High Speed ◽  
High Current ◽  
Pulsed Electron Beam ◽  
Framing Camera
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