scholarly journals Tracing Microalloy Precipitation in Nb-Ti HSLA Steel during Austenite Conditioning

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 243 ◽  
Author(s):  
Johannes Webel ◽  
Adrian Herges ◽  
Dominik Britz ◽  
Eric Detemple ◽  
Volker Flaxa ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Ion Beam ◽  
Hsla Steel ◽  
Isothermal Holding ◽  
Elemental Distribution ◽  
Steel Matrix ◽  
Low Carbon ◽  
Finished Steel ◽  
Characterization Methods ◽  
Resistivity Measurements

The microalloying with niobium (Nb) and titanium (Ti) is standardly applied in low carbon steel high-strength low-alloy (HSLA) steels and enables austenite conditioning during thermo-mechanical controlled processing (TMCP), which results in pronounced grain refinement in the finished steel. In that respect, it is important to better understand the precipitation kinetics as well as the precipitation sequence in a typical Nb-Ti-microalloyed steel. Various characterization methods were utilized in this study for tracing microalloy precipitation after simulating different austenite TMCP conditions in a Gleeble thermo-mechanical simulator. Atom probe tomography (APT), scanning transmission electron microscopy in a focused ion beam equipped scanning electron microscope (STEM-on-FIB), and electrical resistivity measurements provided complementary information on the precipitation status and were correlated with each other. It was demonstrated that accurate electrical resistivity measurements of the bulk steel could monitor the general consumption of solute microalloys (Nb) during hot working and were further complemented by APT measurements of the steel matrix. Precipitates that had formed during cooling or isothermal holding could be distinguished from strain-induced precipitates by corroborating STEM measurements with APT results, because APT specifically allowed obtaining detailed information about the chemical composition of precipitates as well as the elemental distribution. The current paper highlights the complementarity of these methods and shows first results within the framework of a larger study on strain-induced precipitation.

scholarly journals Tracing Microalloy Precipitation in Nb-Ti HSLA Steel During Austenite Conditioning

2020 ◽  
Author(s):  
Johannes Webel ◽  
Adrian Herges ◽  
Dominik Britz ◽  
Eric Detemple ◽  
Volker Flaxa ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Ion Beam ◽  
Hsla Steel ◽  
Isothermal Holding ◽  
Resistivity Measurement ◽  
Hot Working ◽  
Electrical Resistivity Measurement ◽  
Steel Matrix ◽  
Finished Steel ◽  
Resistivity Measurements

Microalloying of low carbon steel with niobium (Nb) and titanium (Ti) is standardly applied in high-strength low-alloy (HSLA) steels enabling austenite conditioning during thermo-mechanical controlled processing (TMCP), which results in pronounced grain refinement in the finished steel. The metallurgical effects of microalloying elements are related solute drag and precipitate particle pinning, both acting on the austenite grain boundary thereby delaying or suppressing recrystallization of the deformed grain. In that respect it is important to better understand the precipitation kinetics as well as the precipitation sequence in a typical Nb-Ti-microalloyed steel. Various characterization methods have been utilized in this study for tracing microalloy precipitation after simulating different austenite TMCP conditions in a Gleeble apparatus. Atom probe tomography (APT), scanning transmission electron microscopy in a focused ion beam equipped scanning electron microscope (STEM-on-FIB) and electrical resistivity measurements provide complementary information on the precipitation status and are correlated with each other. It will be demonstrated that accurate electrical resistivity measurements can monitor the general consumption of solute microalloys (Nb) during hot working which was complemented by APT measurements of the steel matrix. On the other hand, STEM revealed that a large part of Nb-containing particles during hot working are co-precipitated with titanium during cooling from the austenitizing temperature. Precipitates that form during cooling or isothermal holding can be distinguished from strain-induced precipitates by corroborating STEM measurements with APT results. APT specifically allows obtaining detailed information about the chemical composition of precipitates as well as the distribution of elements inside the particle. Electrical resistivity measurement, on the contrary, provides macroscopic information on the progress of precipitation and can be calibrated by APT. The current paper highlights the complementarity of these methods and shows first results within the framework of a larger study on strain-induced precipitation.

Electrical resistivity measurements of heavy ion beam generated high energy density aluminium

2006 ◽  
Vol 39 (17) ◽  
pp. 4743-4747 ◽  
Author(s):  
S Udrea ◽  
N Shilkin ◽  
V E Fortov ◽  
D H H Hoffmann ◽  
J Jacoby ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Energy Density ◽  
Ion Beam ◽  
Heavy Ion ◽  
High Energy ◽  
High Energy Density ◽  
Resistivity Measurements ◽  
Heavy Ion Beam

Study of ion beam induced mixing in Sn/Si system using electrical resistivity measurements

1988 ◽  
Vol 120 (2) ◽  
pp. 387-392 ◽  
Author(s):  
A. J. Abu El-Haija ◽  
K. A. Al-Saleh ◽  
N. A. Halim ◽  
J. M. Khalifeh ◽  
N. S. Saleh
Keyword(s):  
Electrical Resistivity ◽  
Ion Beam ◽  
Resistivity Measurements

Ion-beam mixing kinetics of Fe-Al multilayers studied by in situ electrical resistivity measurements

1984 ◽  
Vol 33 (2) ◽  
pp. 77-82 ◽  
Author(s):  
J. P. Rivi�re ◽  
J. Delafond ◽  
C. Jaouen ◽  
A. Bellara ◽  
J. F. Dinhut
Keyword(s):  
Electrical Resistivity ◽  
Ion Beam ◽  
Ion Beam Mixing ◽  
Resistivity Measurements ◽  
Kinetics Of

Electrical Resistivity of Multilayers During Ion Beam Mixing

1983 ◽  
Vol 27 ◽  
Author(s):  
J. Grilhe ◽  
J.P. Riviere ◽  
J. Delafond ◽  
C. Jaouen ◽  
C. Templier
Keyword(s):  
Electrical Resistivity ◽  
Volume Fraction ◽  
Ion Beam ◽  
Conduction Model ◽  
Ion Beam Mixing ◽  
New Approach ◽  
Saturation Process ◽  
Resistivity Measurements ◽  
Metal Metal

ABSTRACTA new approach is developed, employing “in situ” electrical resistivity measurements, as a tool to study ion beam mixing of evaporated metal-metal multi or bilayers. The electrical resistivity variations measured continuously during the ion bombardment exhibit a monotonical increase and a tendency toward a saturation process allowing to detect precisely the total mixing of the film. The volume fraction of intermixed atoms can be determined within the framework of a simple conduction model. Experimental results are given in the case of Fe-Al and Al-Ag multilayers.

In-situ electrical-resistivity measurements in the high-voltage electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 68-69
Author(s):  
W. E. King
Keyword(s):  
Electrical Resistivity ◽  
Electron Microscope ◽  
High Voltage ◽  
Resistivity Measurements ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Wide Range ◽  
Helium Gas

A side-entry type, helium-temperature specimen stage that has the capability of in-situ electrical-resistivity measurements has been designed and developed for use in the AEI-EM7 1200-kV electron microscope at Argonne National Laboratory. The electrical-resistivity measurements complement the high-voltage electron microscope (HVEM) to yield a unique opportunity to investigate defect production in metals by electron irradiation over a wide range of defect concentrations.A flow cryostat that uses helium gas as a coolant is employed to attain and maintain any specified temperature between 10 and 300 K. The helium gas coolant eliminates the vibrations that arise from boiling liquid helium and the temperature instabilities due to alternating heat-transfer mechanisms in the two-phase temperature regime (4.215 K). Figure 1 shows a schematic view of the liquid/gaseous helium transfer system. A liquid-gas mixture can be used for fast cooldown. The cold tip of the transfer tube is inserted coincident with the tilt axis of the specimen stage, and the end of the coolant flow tube is positioned without contact within the heat exchanger of the copper specimen block (Fig. 2).

The stabilization of B.C.C. Cu in Cu/Nb nanolayered composites

1996 ◽  
Vol 54 ◽  
pp. 228-229
Author(s):  
H. Kung ◽  
A.J. Griffin ◽  
Y.C. Lu ◽  
K.E. Sickafus ◽  
T.E. Mitchell ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Layer Thickness ◽  
Volume Fraction ◽  
Ion Beam ◽  
High Strength ◽  
Cross Sectional ◽  
Metastable Structure ◽  
High Resolution Tem ◽  
Potential Improvement ◽  
Two Phases

Materials with compositionally modulated structures have gained much attention recently due to potential improvement in electrical, magnetic and mechanical properties. Specifically, Cu-Nb laminate systems have been extensively studied mainly due to the combination of high strength, and superior thermal and electrical conductivity that can be obtained and optimized for the different applications. The effect of layer thickness on the hardness, residual stress and electrical resistivity has been investigated. In general, increases in hardness and electrical resistivity have been observed with decreasing layer thickness. In addition, reduction in structural scale has caused the formation of a metastable structure which exhibits uniquely different properties. In this study, we report the formation of b.c.c. Cu in highly textured Cu/Nb nanolayers. A series of Cu/Nb nanolayered films, with alternating Cu and Nb layers, were prepared by dc magnetron sputtering onto Si {100} wafers. The nominal total thickness of each layered film was 1 μm. The layer thickness was varied between 1 nm and 500 nm with the volume fraction of the two phases kept constant at 50%. The deposition rates and film densities were determined through a combination of profilometry and ion beam analysis techniques. Cross-sectional transmission electron microscopy (XTEM) was used to examine the structure, phase and grain size distribution of the as-sputtered films. A JEOL 3000F high resolution TEM was used to characterize the microstructure.

LA-LED X

Alloy Digest ◽  
1970 ◽  
Vol 19 (7) ◽  
Keyword(s):  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Low Carbon ◽  
Steel Company ◽  
Finished Steel ◽  
Screw Machine

Abstract LA-LFD X is a low-carbon, lead-bearing, free-machining, cold-finished steel containing small amounts of tellurium. It is recommended for automatic screw machine operations. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, machining, and joining. Filing Code: CS-35. Producer or source: LaSalle Steel Company.

3D Observation of Elemental Distribution of Si-Device using a Dedicated FIB/STEM System

2005 ◽  
Author(s):  
T. Yaguchi ◽  
M. Konno ◽  
T. Kamino ◽  
M. Ogasawara ◽  
K. Kaji ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Elemental Distribution ◽  
Multivariate Statistical ◽  
X Ray ◽  
Sample Rotation ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Elemental Maps

Abstract A technique for preparation of a pillar shaped sample and its multi-directional observation of the sample using a focused ion beam (FIB) / scanning transmission electron microscopy (STEM) system has been developed. The system employs an FIB/STEM compatible sample rotation holder with a specially designed rotation mechanism, which allows the sample to be rotated 360 degrees [1-3]. This technique was used for the three dimensional (3D) elemental mapping of a contact plug of a Si device in 90 nm technology. A specimen containing a contact plug was shaped to a pillar sample with a cross section of 200 nm x 200 nm and a 5 um length. Elemental analysis was performed with a 200 kV HD-2300 STEM equipped with the EDAX genesis Energy dispersive X-ray spectroscopy (EDX) system. Spectrum imaging combined with multivariate statistical analysis (MSA) [4, 5] was used to enhance the weak X-ray signals of the doped area, which contain a low concentration of As-K. The distributions of elements, especially the dopant As, were successfully enhanced by MSA. The elemental maps were .. reconstructed from the maps.

scholarly journals Electrical Resistivity Measurements and Soundings on Glaciers: Introductory Remarks

1967 ◽  
Vol 6 (47) ◽  
pp. 599-606 ◽  
Author(s):  
Hans Röthlisberger
Keyword(s):  
Electrical Resistivity ◽  
Resistivity Measurements ◽  
Resistivity Method

A brief description of the resistivity method is given, stressing the points which are of particular importance when working on glaciers. The literature is briefly reviewed.

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