Growth of Individual Austenite Grains Measured with 3DXRD Microscopy

2007 ◽  
Vol 561-565 ◽  
pp. 2301-2304 ◽  
Author(s):  
V.I. Savran ◽  
S. Eric Offerman ◽  
Niels H. van Dijk ◽  
Erik M. Lauridsen ◽  
L. Margulies ◽  
...  
Keyword(s):  
Three Dimensional ◽  
European Synchrotron Radiation Facility ◽  
Growth Behavior ◽  
Continuous Heating ◽  
Austenite Formation ◽  
Low Alloy Steels ◽  
Alloy Steels ◽  
Austenite Grains ◽  
Individual Grains

Studying austenitisation in steel, so far, was either limited to observations at the surface of the material or to the determination of the average grain growth behavior in the bulk. The development of the three-dimensional X-ray diffraction (3DXRD) microscope at beam line ID11 of the European Synchrotron Radiation Facility in Grenoble, France, made it possible to study the transformation kinetics in-situ and at the level of individual grains in the bulk of the material. Unique in-situ observations of austenite growth kinetics during continuous heating experiments were made for two commercial low-alloy steels (C22 and C35). The observed growth behavior of individual austenite grains gives a valuable contribution to understanding the phase transformations on heating, i.e. austenite formation from ferrite and pearlite.

Localization of Partial Magnetization around Artificial Slits in Square Bars of Medium Carbon Low Alloy Steel JIS S45C

2011 ◽  
Vol 217-218 ◽  
pp. 1297-1302 ◽  
Author(s):  
M. Uryu ◽  
Katsuyuki Kida ◽  
Takashi Honda ◽  
Edson Costa Santos ◽  
K. Saruwatari
Keyword(s):  
Stress Concentration ◽  
Three Dimensional ◽  
Hall Probe ◽  
Low Alloy Steels ◽  
Film Sensor ◽  
Medium Carbon ◽  
Alloy Steels ◽  
Probe Microscope ◽  
Non Destructive

Fatigue failure of steel occurs when cracks form and grow in the material’s stress concentration area. In order to understand the relation between stress concentration and crack propagation phenomena, non-destructive evaluation methods that can be related to in-situ measurements around the stress concentration area are necessary. In the present work, we developed a scanning Hall probe microscope (SHPM) equipped in a GaAs film sensor and observed three dimensional magnetic fields at room temperature in air. Medium carbon low alloy steels specimens (JIS, S45C) were used in the experiments. Only the area around the artificial slit had been magnetized and the effect of the magnetization area on the artificial slit was observed.

scholarly journals Characterization of the crystal structure, kinematics, stresses and rotations in angular granular quartz during compaction

2018 ◽  
Vol 51 (4) ◽  
pp. 1021-1034 ◽  
Author(s):  
Ryan C. Hurley ◽  
Eric B. Herbold ◽  
Darren C. Pagan
Keyword(s):  
Crystal Structure ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Spherical Particles ◽  
X Ray ◽  
Porosity Evolution ◽  
Individual Grains ◽  
Particle Packings ◽  
Number Of Particles

Three-dimensional X-ray diffraction (3DXRD), a method for quantifying the position, orientation and elastic strain of large ensembles of single crystals, has recently emerged as an important tool for studying the mechanical response of granular materials during compaction. Applications have demonstrated the utility of 3DXRD and X-ray computed tomography (XRCT) for assessing strains, particle stresses and orientations, inter-particle contacts and forces, particle fracture mechanics, and porosity evolution in situ. Although past studies employing 3DXRD and XRCT have elucidated the mechanics of spherical particle packings and angular particle packings with a small number of particles, there has been limited effort to date in studying angular particle packings with a large number of particles and in comparing the mechanics of these packings with those composed of a large number of spherical particles. Therefore, the focus of the present paper is on the mechanics of several hundred angular particles during compaction using in situ 3DXRD to study the crystal structure, kinematics, stresses and rotations of angular quartz grains. Comparisons are also made between the compaction response of angular grains and that of spherical grains, and stress-induced twinning within individual grains is discussed.

In Situ Neutron Diffraction during Thermo-Mechanically Controlled Process in Low Alloy Steels

2006 ◽  
Vol 118 ◽  
pp. 419-424
Author(s):  
M.S. Koo ◽  
Ping Guang Xu ◽  
J.H. Li ◽  
Yo Tomota ◽  
O. Muransky ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Volume Fraction ◽  
Structural Evolution ◽  
Low Alloy Steels ◽  
Controlled Processing ◽  
Ferrite Transformation ◽  
Alloy Steels ◽  
Time Division ◽  
In Situ Neutron Diffraction

A challenge was made to examine the micro-structural evolution during thermomechanically controlled processing (TMCP) by in situ neutron diffraction. Since the neutron beam is too weak to achieve a time-division measurement to follow a rapid transformation in alow carbon steel, 2%Mn was added to make the austenite to ferrite transformation slower. Round bar specimens were heated up to 900°C with an electrical resistance method, then cooled down to 700°C, and compressed by 25% followed by step-by-step cooling. During the step-by-step cooling, neutron diffraction profiles were obtained and the volume fraction of ferrite, phase stresses and FWHM were analyzed. Using a similar TMCP simulator, specimens were quenched into water at several stages of the heat schedule to freeze the corresponding microstructures, which were observed with OM and SEM. As results, the ferrite volume fraction determined by neutron diffraction on cooling agrees well with that by microscopy. It is found that the austenite deformation and/or Nb addition accelerate the ferrite transformation to result in finer grain size.

DIFFERENT GROWTH BEHAVIOR OF Ge, Al AND Sb ON GRAPHITE

2006 ◽  
Vol 13 (02n03) ◽  
pp. 287-296 ◽  
Author(s):  
WENDE XIAO ◽  
ZHIJUN YAN ◽  
SUNIL SINGH KUSHVAHA ◽  
MAOJIE XU ◽  
XUE-SEN WANG
Keyword(s):  
Double Layer ◽  
Room Temperature ◽  
Pyrolytic Graphite ◽  
Three Dimensional ◽  
Growth Behavior ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Defect Sites ◽  
Unique Nature

Growth of Ge , Al and Sb on highly oriented pyrolytic graphite (HOPG) was systematically investigated using in situ scanning tunneling microscopy (STM). At room temperature (RT), three dimensional (3D) clusters of all three elements nucleate and grow at the step edges and defect sites of HOPG. The clusters of Al and Ge form chains, while Sb islands are mostly isolated. With further deposition at RT, Al clusters grow and coarsen into faceted islands with craters on the top (111) facets, whereas ramified single- and double-layer cluster islands are observed for Ge . When deposited or annealed at T ≥ 175° C , Ge forms crystallites but with randomly oriented facets. As spherical Sb islands grow beyond certain size, (111) facets appear on the top. Additionally, crystalline 2D films and 1D nanorods are observed for Sb deposited at RT. At T ≈ 100° C and higher flux, only the 2D and 1D Sb islands are formed. These different growth behaviors reflect the unique nature in which the atoms (molecules), clusters and crystallites of each element interact with HOPG surface and with each other.

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