bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement in Specific Electric Resistance of Bi1.5Pb0.5Sr1.7Y0.5Co2O9-δ by Texture Development
Authors: Fukutomi Hiroshi , Iguchi Eisuke , Shibuya Kyohei
Published: March 2009

Thermoelectric oxide Bi1.5Pb0.5Sr1.7Y0.5Co2O9- δ is produced by sintering method.
Uniaxial compression deformation is performed on the oxide under various strain rates at 1113K,
close to the melting temperature. After deformation, density, microstructure, texture and
thermoelectric characteristics such as specific electric resistance and Seebeck coefficient, are
experimentally studied. Deformation mechanism is examined by stress change test. It is found that
the oxide plastically deforms mainly by the motion of dislocations at the present temperature,
resulting in an increase in density as well as the development of texture. It is concluded that the
specific electric resistance extensively decreases by the high temperature compression deformation
through densification and texture development.
Application of Asymmetric Rolling to Texture Control of Silicon Steel
Authors: Sha Y.H. , Zhou S.C. , Pei Wei , Zuo Liang
Published: March 2009

The influences of different rolling modes and speed ratios on cold rolling texture
development, and the characteristics of recrystallization textures after ordinary annealing as well as
magnetic annealing have been investigated for non-oriented silicon steel. Results show that the
through-thickness deformation textures were effectively changed by asymmetric cold rolling even
in the case of small speed ratios, and the recrystallization textures were modified with the enhanced
favorable {100} and η (<100>//RD) texture components by magnetic annealing. Much improved
magnetic properties can be obtained through optimization of asymmetric rolling and annealing
parameters. Thus, application of asymmetric cold rolling and magnetic annealing might open up
new possibilities for texture control in high-grade silicon steel production.
Texture and Microstructure of Cold Rolled and Recrystallized Pure Niobium
Authors: Abreu H.F.G. , Tavares Sergio S.M. , Carvalho S.S. , Eduardo T.H.T. , Bruno Antonia Daniele S. , Prado da Silva Marcelo Henrique
Published: March 2009

Crystallographic macrotexture of pure niobium cold rolled to 30, 60, 80 and 90% reduction
was analyzed by X-ray diffraction and compared with low carbon steel texture. Annealed samples
from 800oC, to 1200oC were investigated by X-ray diffraction and electron back scattering
diffraction (EBSD). The texture of cold rolled polycrystalline niobium is characterized by a
component {001}<110> that increases in intensity with the cold work percentage. After annealing,
the component {001}<110> spreads out about 20o.
Effects of Electric Field Annealing on Recrystallization Texture and Plastic Strain Ratio (r-Value) of IF Steel Sheet
Authors: Zhao Xiang , He Chang Shu , Xu J. , Zuo Liang
Published: March 2009

Effects of electric field annealing on recrystallization texture and average
plastic strain ratio (r value) of IF steel sheet were studied by mean of X ray diffraction
ODF analysis and the tensile test. Specimens of 75% cold-rolled IF steel sheet were
annealed at 850flC for 25min,with and without electric field annealing respectively.
Results show that the electric field annealing does not change the type of
recrystallization texture and its formation mechanism in IF deep-drawing steel sheet,
but improves the formation and development of recrystallization i-fiber texture,
enhances the intensity of i-fiber texture, and retards the formation and development of
c-fiber texture. Comparing with the conventional annealing, electric field annealing
improves the average plastic strain ratio (r value). Possible reasons for the
intensification of recrystallization i-fiber texture with the electric field applied may
attribute to the reduction of stored energy, thus hindering the formation of other
orientated nuclei and enhancing the nucleating ratio of i-oriented nuclei. And the
intensification of recrystallization i-fiber texture was considered as the main reason
for the enhancement of the plastic strain ratio (r value) in IF steel sheet.
Synthesis of Carbon Nanotubes and its Applications in Composites and Field Emission Light
Authors: Tai Nyan Hwa , Yeh Meng Kao , Yang Chien Hsin , Tseng Shis Hao , Chiu Chien Chao , Tsai Tsung Yen , Liu Jia Hau , Peng Tai Hao
Published: March 2009

Two processes, the floating catalyst chemical vapor deposition (CVD) process and the
rapid heating and cooling (RHC) process, were adopted for synthesizing single walled carbon
nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs). Batch production of SWNTs
and MWNTs with the diameters of 0.8~1.5 nm and 15~40 nm, respectively, were prepared using
the floating catalytic chemical vapor deposition (CCVD) process. The production rate is 70±20 mg
every 10 minutes. The as-synthesized carbon nanotubes (CNTs) were used for fabricating carbon
nanotubes reinforced composites and field emitter for lighting. On the study of nano-composites,
around 70% enhancement of tensile strength was detected when 1.5 wt% MWNTs in the form of
network structure were introduced to the phenolic matrix. Comparisons on the mechanical
properties of the composites reinforced with the network MWNTs and SWNTs were made.
Microstructures of the MWNTs and SWNTs were studied by Field Emission Scanning Electron
Microscope (FESEM) and High Resolution Transmission Electron Microscope (HRTEM). In the
RHC process for fabricating the device for lighting, the carbon nanotube array was grown on a
silicon substrate which was pre-coated with a catalyst thin film. The synthesis process was
performed in a thermal CVD chamber equipped with a rapid heating apparatus. The as-synthesized
CNT array was then transferred onto the substrate which was coated with silver paste. After heat
treatment, field emission properties of the CNT-based cathode were tested, high current density of
35 mA/cm2 and low turn-on voltage of 0.65 V/μm were achieved in this work.
Behavior of Oxide Film in Transient-Liquid-Phase Bonding of Tin with Filler of Bismuth Film
Authors: Koyama Shinji , Takahashi Makoto , Ikeuchi Kenji
Published: March 2009

The bond interface of a TLP (Transient Liquid Phase) bonded tin has been observed
with a TEM to investigate the effect of the liquid phase on the behavior of the superficial oxide
film at the interface during the bonding process. In the solid-state-diffusion bonded joint
without filler, abundant oxide inclusions were observed to be distributed within a region of a
few 100 nm widths along the bond interface. In comparison with this, the liquid phase
introduced by the eutectic reaction of the bismuth filler with the tin substrate decreased the
width of the interfacial region involving abundant oxide inclusions to form a rather layer
structure a few 100 nm thick consisting mainly of SnO2. It also enhanced the annihilation of the
uncontacted areas at the interface. The layer of the oxide became discontinuous and coalesced
with an increase in bonding temperature and pressure, and areas where no oxide inclusion could
be observed at the interface were increased, when the liquid phase was formed. Owing to these
effects, the bond strength rose at lower bonding temperatures and pressures when the bismuth
filler was applied.
Ageing of C-Containing and C-Free Ti-15Cr and Ti-15-3
Authors: Wu Xin Hua , Del Prado Joaquin , Hu D. , Huang A. , Chu M.Q. , Loretto M.H.
Published: March 2009

Samples of Ti-15Cr and Ti-15V-3Sn-3Al-3Cr (wt%) containing controlled additions of
carbon up to 0.2wt% and different oxygen contents have been quenched and aged at temperatures
between 400 and 600°C. Optical, scanning and analytical transmission electron microscopy have
been used to characterise the microstructures of the quenched and aged samples. Hardness testing
has been used to follow the kinetics and extent of age hardening, which are accelerated in Ccontaining
samples. The addition of carbon results in the formation of Ti(CxOy) precipitates which
pin grain boundaries in forged samples so that the grain size in the quenched C-containing samples
is about a factor of ten less than that in the C-free samples. In the C-free samples coarse grain
boundary alpha tends to form, but in the C-containing samples alpha precipitation is more uniform
throughout the beta grains. The extent of omega precipitation is very different in the two alloys; the
Ti-15Cr alloy forms athermal omega in the as-quenched samples and large omega precipitates are
formed on ageing at 400°C. No evidence for omega has been obtained in the Ti-15-3. The
hardening responses and microstructural observations are interpreted in terms of the different grain
boundary oxygen contents in the C-containing and C-free samples and the different roles of omega
and of carbon in the two alloys.
The Effect of Oxygen on Heat Treatment Behavior of Titanium-50mass%Tantalum-5mass%Zirconium Alloy
Authors: Ikeda Masahiko , Mori Masaaki
Published: March 2009

To develop new shape memory and super-elastic alloys for medical applications, titanium
alloys using non-toxic metallic elements, such as Ta and Nb, are being actively investigated.
In this study, aimed at developing new shape memory Ti alloys, we investigate the effect of
oxygen, a powerful alpha stabilizing interstitial element, on the heat treatment behavior of
Ti-50mass%Ta-5mass%Zr through electrical resistivity and Vickers hardness measurements
and shape-recovery tests. Ti-50Ta-5Zr-0.14Ox and 0.33Ox alloys, and the β and α” bi-phase
was confirmed by XRD. Only the β phase was identified in the Ti-50Ta-5Zr-0.62Ox alloy.
Upon isochronal heat treatment, the resistivity at LN and resistivity ratio of Zr-0.33 and
0.62Ox alloys decreased up to around 523 K. In the 5Zr-0.62Ox alloy, orthorhombic
martensite and the α” and β phases were identified in the specimens heat-treated at 473 and
523 K. The decreases in resistivity at liquid nitrogen temperature and resistivity ratio are
due to the formation of α” during isochronal heat treatment. The formation of α” was
confirmed by X-ray diffraction in the 5Zr-0.62Ox alloy. The shape memory effect was
observed in 5Zr-0.14 and 0.33Ox alloys and the shape recovery ratio of both alloys was about
40% at 673 K.
Beta Phase Decomposition in a TiAl Alloy during Continuous Cooling
Authors: Hu D. , Jiang H. , Loretto M.H. , Wu Xin Hua
Published: March 2009

Beta phase decomposition in Ti-44Al-4Nb-4Hf-0.1Si during continuous cooling from β
phase field has been investigated. A wide cooling rate range (0.3-1000°Cs-1) was provided by
mainly using Jominy end quenching, which has been introduced into TiAl research recently,
together with iced brine quench (IBQ) and furnace cooling (FC). At different cooling rates beta
phase decomposes via different paths through diffusion or diffusionless mechanisms and lamellar
transformation may occur after β decomposition at certain cooling rates.
Oxidation Effects during High Temperature Deformation of CP Ti Alloy
Authors: Tan Ming Jen , Zhu X.J. , Thiruvarudchelvan S. , Liew K.M.
Published: March 2009

This work reports the influence of oxidation on the superplasticity of commercially pure
titanium at high temperatures. Uniaxial tensile tests were conducted at temperatures in the range
600-800°C with an initial strain rate of 10s-1 to 10s-3. This study shows that oxidization at the
surface of the alloy causes oxide film on the surface of commercially pure titanium alloy, and the
thickness of oxide film increase with increasing exposure time and temperature. XRD analysis
shows that the oxide film consists of TiO2. Because this oxide film is very brittle, it can induce
clefts and degrade the ductility of the titanium at high temperatures. The mechanism of the initial
clefts was investigated and a model for the cleft initiation and propagation during high temperature
tensile test was proposed.
Controlled Plasticity Burnishing to Improve the Performance of Friction Stir Processed Ni-Al Bronze
Authors: Prevey Paul S. , Hornbach Douglas J. , Jayaraman N.
Published: March 2009

Friction stir welding (FSW) allows the joining of aluminum alloys in ways previously
unattainable offering new manufacturing technology. Friction stir processing (FSP) of cast
alloys such as Ni-Al bronze eliminates casting voids and improves the properties to that of
wrought material. However, the local heating produced by both FSW and FSP can leave a
fusion zone with reduced mechanical properties and a heat-affected zone with tensile residual
stresses that can be deleterious to fatigue performance. Controlled plasticity burnishing (CPB) is
an established surface treatment technology that has been investigated and described extensively
for the improvement of damage tolerance, corrosion fatigue, and stress corrosion cracking
performance in a variety of alloys. Mechanical CPB processing in conventional CNC machine
tools or with robotic tool positioning is readily adapted to industrial FSW and FSP fabrication of
components, either simultaneously or as a post process.
CPB was applied to FSP Ni-Al Bronze to produce a depth of compression of 2.5 mm and a
maximum subsurface magnitude of –150 ksi. The effect of FSP on the fatigue performance in a
saltwater marine environment and in the presence of foreign object damage (FOD) was
documented with and without CPB processing. FSP was found to increase the fatigue strength
of the Ni-Al Bronze by 70% without affecting the corrosion behavior of neutral salt solution.
FSW actually produced a more noble material in the acidic salt solution. CPB after FSP
mitigated damage 1 mm deep.
Microstructure of SiC/Cu Interface by Pulsed Electric-Current Bonding
Authors: Nishimoto Akio , Akamatsu Katsuya , Ikeuchi Kenji
Published: March 2009

Pulsed electric-current sintering (PECS) was applied to the bonding of SiC
(pressureless-sintered silicon carbide) to Cu (oxygen-free copper) using a mixture of Cu and Ti
powders as an intermediate layer. The influences of the intermediate powders on the bond strength
of the joint were investigated by observation of the microstructure. The bonding was carried out at
carbon-die temperatures from 973 to 1173 K at a bonding pressure of 10 MPa for 3.6 ks. The
application of intermediate layers of 100% Ti, 95% Ti + 5% Cu, and 5% Ti + 95% Cu remarkably
improved the bond strength as compared with direct bonding without an intermediate powder. SEM
observations of the joint with the intermediate powders revealed that a Cu solid-solution layer, a
TiC layer, and a Ti5Si3 layer had covered most of the interface, similar to those observed in the
friction-bonded and pulsed-electric current bonded joints of SiC to Cu in which the application of a
Ti foil as an intermediate layer remarkably improved the bond strength.
Precise Resistance Welding with Wire Insert
Authors: Terajima Takeshi , Kuroda Toshio
Published: March 2009

Butt resistance welding of super duplex stainless steel type 329J4L with inserting type
316L stainless steel wires was investigated. When the base material temperature was increased from
room temperature to 1373 K at the heating rate of 550 K /sec, base materials were jointed through
the insert wires. HAZ (heat affected zone) of the joint interface were less than 80 μm. In this jointing
technique, the insert wires played an important role of concentrating current on the wires and
increasing their temperature up to melting point or near melting point. Thermal analysis using thermography
revealed that insert wires were adequately heated just after current started at a load of 10
N. When the welding was performed at a load of 70 N, joint area was increased by plastic deformation
of the base material. That led to decrease of current concentration. Consequently insert wires
were jointed in the solid state.
Ultrasonic Friction Power in Microelectronic Wire Bonding
Authors: Mayer Michael , Zwart Andrew
Published: March 2009

An integrated sensor method is used to measure interfacial temperature profiles with an
ultrasonic friction test process. The profiles are compared to numerical results obtained by a
transient thermal 2D axisymmetric finite elements (FE) analysis. In the experiments, the 50 $m
diameter gold balls used in wire bonding are deformed by the capillary tool during impacting on the
flat surface of a silicon chip (contact zone). The deformed balls then are pressed onto the SiO2 layer
on the chip and vibrated with various amplitudes of 128 kHz ultrasonics. The 52 $m diameter
contact zone is surrounded in 14 $m distance by a 50 aluminum resistor which is used as a
resistive temperature detector. Temperature increases of typically 0.18 K and up to 0.3 K are
measured by the sensor close to the heat source at the contact zone, corresponding to 3.1 K and
5.2 K at the interface as suggested by the FE model. With typical bonding parameters, the contact
zone friction power is determined to be 4.4 mW which is less than 2 % of the electrical energy
delivered to the used ultrasonic transducer type.
Advancement in Prediction and Control of Welding Residual Stress and Distortion
Authors: Yang Y.P. , Jung G.
Published: March 2009

Weld modeling technology and control and mitigation techniques of residual stress and
distortion have made a significant progress in the past decade. Q-Weld as the latest development in
weld modeling technique can provide a solution in an extremely short time compared to a traditional
thermo-elastic-plastic analysis. Three distortion control techniques, transient thermal tensioning, low
stress non-distortion and in-process rolling, are discussed in this paper.
Joining by Forming with a Flat Counter Tool - A New Way of Joining Magnesium Components
Authors: Neugebauer Reimund , Dietrich Stephan , Kraus Christian
Published: March 2009

Joining by forming of magnesium alloys is restricted by the limited forming capability of
magnesium at room temperature. For this reason heating of the parts to temperatures of 220 °C or
more is required to form joints without cracks. State-of-the-art joining by forming methods (such as
clinching or self-pierce riveting) are usually working with a contoured die as a counter tool.
Researches on these joining methods have shown that a minimum heating time of 3 to 6 seconds is
needed to achieve joints of acceptable quality. In this paper two new clinching methods “dieless
clinching” and “dieless rivet-clinching” shall be introduced. Both methods work with a flat anvil as
a counter tool, thus offering important advantages for the application in joining of Mg/Mg, Al/Mg
or Fe/Mg joints. In joining by forming with a flat counter tool the proportion of crack inducing
tensile stresses in the bottom part during the joining process is very low. Moreover the heat transfer
between the heated anvil and the parts is comparatively fast. That makes it possible to decrease the
heating time in joining by forming with a flat counter tool to only one second or less. The dieless
clinching process was simulated using the Finite Elements Method (FEM) to analyze the influence
of geometrical parameters of the punch and the process parameter clamping force. Furthermore the
limitations of the new dieless joining method were investigated.
Braze Pressure Welding (BPW) - A New Method for Joining Steel Pipes -
Authors: Suzumura Akio
Published: March 2009

Braze Pressure Welding (BPW) with high frequency induction heating is a newly developed
pressure welding technique using interlayer metals for welding the general steel pipes for pipe arrangement in
buildings. BPW enables to make joints by solid-state welding in air using a flux sheet which is also developed
for this technique. In this method, the interlayer metal is expected to play the primary role in making high
performance joints. At a joining temperature, the melted interlayer removes contaminations from the joining
surfaces of the base metals. Then the liquid filler is discharged from the joining interface by the joining
pressure, and forms fillets at the gaps around the joint. In this stage, the joining pressure is relatively small, so
the welding deformation can be restrained to a minimum. The fillets have the effects both on relaxing the stress
concentration at the joint and on increasing the joining area, which contribute to the strengthening of the joint.
Thus, the high quality pipe joining without the dispersion in joint properties due to welder’s skill can be
performed. In this report, the concept and merits of BPW are explained, and the results of the investigation on
the cleaning effect of the interlayer metal and the effects of fillet formation on strengthening the joint are
discussed. The practical application of BPW in Japan is also introduced.
A Study on Fatigue Strength Improvement of Aluminum Alloy Resistant Spot Welds by Cold Working
Authors: Kim D. , Blake D. , Ryu Seung Jin , Lim Byeong Soo
Published: March 2009

Resistance spot welds (RSW) have been widely used in the sheet metal joining process due
to high productivity, low cost and convenience. The application of aluminum alloys in automobile
manufacturing has resulted in the reduction of weight in vehicle, fuel economy and improvement of
drivability and driving performance. Therefore, the resistance spot weld (RSW) process has attracted
attention to fabrication of aluminum structures. However, applications of Al RSW are limited due to
the unreliable durability of the weld-bonded joints. This study presents an experimental investigation
on the use of a post-weld cold working process to improve the fatigue strength of Al RSW. The
post-weld cold working process includes a pair of uniquely shaped indenters that are pressed or driven
into the structure in order to induce the compressive residual stresses around the RSW. The
mechanical properties of the post-weld cold worked Al RSW were investigated, including the
experimental results of fatigue. The effect of the post-weld cold working process parameters on the
fatigue strength of the Al RSW was also investigated. Comparisons of the mechanical properties and
qualitative results between the as-welded RSW specimens and the post-weld cold worked RSW
specimens of each post-cold working parameter have been carried out. Also, discussions on the
experimental results using the finite element method (FEM) for the post-weld cold working
parameters are performed.
A Study of Bubble Entrainment as Related to Runner Velocity in Aluminum Sand Castings Using the Cosworth Process
Authors: Burford John C. , Sokolowski Jerry
Published: March 2009

Traditional gravity pour down-sprue methods of filling moulds in the making of
aluminum castings inherently lead to oxide and air bubble entrainment. The reason for this is found
in the high velocities the metal flow experiences during the filling of a mould. The Nemak Windsor
Aluminum Plant (WAP) produces cylinder blocks using the low-pressure Cosworth process, which
includes low velocity up-hill filling of the sand mould package. This doctrine is followed in all
except one part of the process: the runner system. The nature of the resulting defect is generally
known as Head Deck Porosity.
Runners were cast full in open production runners at three different velocities with the resulting
quickly chilled castings analyzed using X-ray radioscopy, and Scanning Electron Microscopy.
Results reveal that the subject bubble porosity is indeed the result of air entrained during initial
transient flow within the production runner system whose velocity is higher than the critical value of
0.5ms-1. This theoretical value is corroborated by experimental results. In addition, a new "sessile"
runner of optimized shape, filled at a velocity slower than the critical value, is proposed and
analyzed using Magmasoft mould fill modelling software. The design can potentially replace the
existing runner providing a casting free of entrained air.
Abnormal Tin Whisker Growth in Rare Earth Element-Doped Sn3Ag0.5CuXCe Solder Joints
Authors: Chuang Tung Han , Yen Shiu Fang
Published: March 2009

In this study, 0.1~1.0 wt.% of pure Ce was added into a Sn3Ag0.5Cu solder alloy,
resulting in the formation of precipitated CeSn3 clusters of a size greater than 20 1m in the
reflowed solder matrix. After natural aging at room temperature for more than 3 days,
oxidation on the surface of the CeSn3 clusters was much heavier than in the undoped
Sn3Ag0.5Cu solder matrix. In addition, many tin whiskers with a diameter of about 0.1 to 0.3
μm had been squeezed out of the oxide layer of the CeSn3 precipitates. The increase in aging
time at room temperature causes the tin whiskers to grow rapidly. The whiskers can grow
even to a length of over 300 μm after 21 days of storage. The whisker growth rate in one
particular case reached 8.6Å/s after room temperature storage for only one day. The whiskers
formed during storage at a higher temperature (1500C have a coarse diameter of 1 to 3 μm.
In some cases, high temperature storage results in the formation of short whiskers in a hillock
shape with a diameter of about 5 to 10 μm.
FE Modelling of Mechanical Tensioning for Controlling Residual Stresses in Friction Stir Welds
Authors: Richards David G. , Prangnell Phil B. , Withers Philip J. , Williams Stewart W. , Wescott Andrew , Oliver E.C.
Published: March 2009

Although Friction Stir Welding (FSW) avoids many of the problems encountered when
fusion welding high strength Al-alloys, it can still result in substantial residual stresses that have a
detrimental impact on service life. An FE model has been developed to investigate the effectives of
the mechanical tensioning technique for controlling residual stresses in FSWs. The model purely
considered the heat input and the mechanical effects of the tool were ignored. Variables, such as
tensioning level, heat input, and plate geometry, have been studied. Good general agreement was
found between modelling results and residual stress measurements, justifying the assumption that the
stress development is dominated by the thermal field. The results showed a progressive decrease in
the residual stresses for increasing tensioning levels and, although affected by the heat input, a
relatively low sensitivity to the welding variables. At tensioning levels greater than ~ 50% of the room
temperature yield stress, tensile were replaced by compressive residual stresses within the weld.
Minimization of Heat-Affected Zone Size in Welded Ultra-Fine Grained Steel under Cooling by Liquid Nitrogen during Laser Welding
Authors: Hamatani Hideki , Miyazaki Yasunobu , Otani Tadayuki , Ohkita Shigeru
Published: March 2009

Ultra-fine grained steel (UFGS) with an average grain size of less than 1μm has been
developed and is expected to demonstrate superior properties. However, its welded heat-affected zone,
HAZ, substantially affecting the strength of a welded joint, will be easily softened after welding.
Therefore, minimization of UFGS’s HAZ size during laser welding was carried out using the cooling
conductor liquid nitrogen. It was found that a shielding gas with adequate flow rate for the liquid
nitrogen depth was used to displace nitrogen on the area of laser beam irradiation to stabilize the weld
bead. Also, because YAG laser system was mainly used because it has a lower laser induced plasma or
plume temperature, which results in a decreased occurrence of pit and blowhole. HAZ size
minimization strongly depends on the initial plate temperature. Reduced initial plate temperature
shrinks the specific heated temperature range in which softening occurs. However, due possibly to
decreasing thermal conductivity under room temperature, which prevents heat removal, the benefit of
reducing the initial plate temperature is limited. The optimal initial temperature to minimize the HAZ
size, in the present work, was found to be 123K.
Insulated Rail Joints for Signalling Applications
Authors: Huang S.W. , Burgess S. , Németh Wehrmann L. , Nolan D. , Chandra Tara
Published: March 2009

Insulated rail joint assemblies provide electrical insulation between two sections of rail
for signalling purposes. In this work, rail steel was successfully bonded to PSZ ceramic using an
active brazing technique. In order to increase the wettability of the PSZ ceramics, titanium coating
was deposited on the ceramic surface using a filtered arc deposition system. A filler metal called
BVAg-18 (60%Ag-30%Cu-10%Sn) was used and the joining was performed at a temperature of
750 °C.
Bonding between partially stabilised zirconia and rail steel with BVAg-18 filler metal was not
achieved using a standard brazing method. Bonding did occur with the BVAg-18 filler metal using
the advanced brazing technique of active metal brazing, with best results obtained using a brazing
temperature of 750oC and a dwell time of 10 minutes. The microstructure of the coating and joint
interface were characterised by XRD, SEM and EDS.
Analysis of the Welding Materials by OPA Technique
Authors: Li Mei Ling , Yang Zhi Jun , Zhang Xiu Xin , Chen Ji Wen , Wang Hai Zhou
Published: March 2009

Original position statistic distribution analysis (OPA) technique is a new kind of analysis
method that can be used to detect the segregation, porosity and non-metal inclusion of iron and steel
material. In the present paper, the technique has been applied to analyze two middle and low alloy
welding plate samples. One sample is normal and there is no any defect in its welding seam,
whereas the other sample has one obvious little defect in its welding seam. For each sample, both
the welding seam and the mother material were scanned and analyzed, and the continuous content
distribution of each element in scan area was thus accurately obtained. From the content distribution
map, the weld shape and the transition zone were directly observed. By using the content curve
from mother material to the welding seam, the content change range and its change gradient were
calculated. These two parameters were suggested to evaluate the quality of the welding seam and
the welding technology. For the sample with the little defect, in its defect region the contents of C
and S presented higher, whereas the contents of metal elements such as Ni, Cr, Mn, Mo, Al
presented lower. This result gave the reason why its mechanics property was relatively bad. It was
suggested that the defect completely resulted from another kind of material.
Effects of Chemical Compositions of Welding Rods on J-R Fracture Resistances and Tensile Properties of Type 347 Welds
Authors: Yoon Ji Hyun , Lee Bong Sang , Yoon Eui Pak
Published: March 2009

The objective of this investigation was to correlate the chemical composition of welding
rods for gas tungsten arc welding with the fracture resistance and tensile properties of type 347 welds
through the systematic tests and microstructural analyses. Five weld metals which differed in contents
of carbon, nitrogen and niobium each other and a high δ-ferrite containing weld metal were deposited
by the six different welding rods. J-R fracture resistance and tensile properties were evaluated for the
type 347 welds. The microstructural examinations were performed to relate key microstructural
features to mechanical properties. It was found that the contents of Nb(C,N) precipitates in type 347
welds were determined by the mixed function of carbon and nitrogen and niobium contents in
welding rods. The strengths of type 347 welds were in direct proportion to the contents of Nb(C,N)
and J-R fracture resistances were inversely proportional to the contents of Nb(C,N). It was concluded
that the type 347 weld with high fracture resistance and adequate strength was obtainable by
controlling the sum of carbon and nitrogen contents near 0.1wt% and a limitation of the carbon
content below 0.04 wt% in welding rod.
Physical Simulation of Thin Slab Continuous Casting
Authors: Mandziej Stan T. , Vosburgh J.D. , Kawalla Rudolf , Schoss H.G.
Published: March 2009

Thin slab continuous casting (TSCC) has recently become a winning technology in production
of automotive steels in particular those of deep-drawing quality for car body panels. By
combining the TSCC with direct rolling while retaining the heat in the process, thin steel sheets
can be produced with high efficiency at much lower cost than with the former cold rolling /
annealing procedures. However, difficulties appear when higher strength medium-alloyed or
micro-alloyed steels have to be manufactured by this method. Some alloying elements, which
tend to segregate, make the as-solidified dendritic microstructure prone to hot cracking and then
require well-controlled cross-reductions during subsequent rolling or thermal-mechanical
treatment to homogenize microstructure and get optimum properties.
Physical simulation appears to be an adequate method to generate dendritic microstructures
characteristic of the continuously cast thin slabs, thus avoiding costly experiments on full- scale
production lines. The direct rolling simulator HDS-V40, designed and manufactured by
Dynamic Systems Inc., allows controlled melting and solidification of a central portion of
10*50*165mm flat bar, and after solidification deforming the dendritic microstructure by multistep
plane strain compression to simulate hot rolling. In the molten pool formed in the sample,
the dendrites grow similarly like it appears in the industrial thin slab casting, i.e. from the
crystallization front defined by main directions of the heat flow to the supporting base and to
the (already) solid portion of the slab. In the paper presented are metallographic evidences
confirming the accuracy of this physical simulation method.
Nitriding Behavior and Strengthening Mechanism of Ti Added Steels
Authors: Kusumi K. , Senuma Takehide , Suehiro M. , Sugiyama Masaaki
Published: March 2009

The nitriding process is one of the common methods for surface hardening, and consists of heat
treatment in a furnace for many hours. The nitriding behavior and strengthening mechanism of Ti added
steels in the nitriding process, which is applicable to a high temperature and rapid process such as the
continuous annealing of steel strip, were investigated.
The sheets were hardened only near the surface. The hardening of the surface layer is due to the formation
of clusters or fine precipitates with disc-like shape consisting of titanium and nitrogen. The maximum
hardness depends on the content of Ti in the steel while the annealing time and the concentration of NH3
influence the depth of the hardened zone affected by nitriding. It is thought that the hardening only near
surface improve bending stiffness without significant increase of yield stress. So there is a possibility that the
surface hardening improves the dent resistance of automobile outer panels without significant worsening of
the surface deflection.
To study these behaviors theoretically, a model for predicting the precipitation behavior due to nitriding has
been developed. The experimental results can be reasonably explained by the model calculations. And also,
the estimation of the amount of strengthening was carried out. It indicated that the strengthening mechanism
is mainly the precipitation hardening of TiN that could be Ti nitrides or Ti-N clusters.
Precipitation of Niobium Carbonitrides: Chemical Composition Measurements and Modeling
Authors: Perez Michel , Courtois Eglantine , Acevedo Reyes Daniel , Epicier Thierry , Maugis Philippe
Published: March 2009

High Resolution Transmission Electron Microscope and Electron Energy Loss
Spectroscopy and have been used to characterize the structure and chemical composition of
niobium carbonitrides in the ferrite of a Fe-Nb-C-N model alloy at different precipitation stages.
Experiments seem to indicate the coexistence of two types of precipitates: pure niobium nitrides
and mixed sub-stoichiometric niobium carbonitrides. In order to predict the chemical composition
of these precipitates, a thermodynamical formalism has been developed to evaluate (i) the
nucleation and growth rates (classical nucleation theory) and (ii) the chemical composition of nuclei
and existing precipitates. A model based on the numerical resolution of former equations, is used to
compute precipitates size distribution evolution at a given temperature. The predicted compositions
are in very good agreement with experimental results.
Metal Dusting and Oxidation at 593 and 704°C
Authors: Varma S.K. , Putrevu Aditya , Pasala Maduri , Zeng Z. , Natesan Ken
Published: March 2009

Experiments involving metal dusting in carbonaceous atmosphere and oxidation in air have
been carried out at 593 and 704oC using T22, T91 and 800 alloy steels. The effect of Cr on these
two processes can be understood because of their compositions. In general, the resistance to both
metal dusting up to 1000 hours and oxidation up to 456 hours has been found to improve with
increase in Cr content from 2.36 to 21.6%. However, mechanisms change from spalling to oxide
scale in oxidation and from uniform metal dusting to pitting in metal dusting as the amount of Cr
increases in these steels. Pitting corrosion shows higher C carbon concentration in the pits than at
locations away from the pits. A detailed analysis has been performed to evaluate the scale and
spalled materials in terms of oxide characterization using XRD, AES, SEM, EDS on SEM, optical
microscopy and TEM.
Development of Low Carbon Boron Steel for Wire Drawing
Authors: Camurri Carlos , Carrasco C. , Bello I. , Trucco M.
Published: March 2009

From the mechanical point of view, the successful cold drawing of wire-rods of low carbon
steel requires a high ductility and a ratio between the yield stress and tensile strength as lowest as
possible, both for diminish the fractures during the process. Small boron additions in the cast of this
kind of steel produce an increase in the size of austenitic grain, and consequently the ferritic one, and
a diminution of the deformation hardening due to the reduction in the nitrogen content in the solid
solution. In this way, the goal of this work is to study the effect of small boron additions (67 to 117
ppm) in the mechanical properties of 5.5 mm diameter wire-rods of low carbon steel.
The wire-rods were characterized by means of traction tests, metallographic analysis with optic and
electronic microscopy, and the results were compared with the corresponding one for wire-rod of
standard steel, i.e., without boron contents.
The metallographic analysis confirms the increase in size of ferritic grain. The measured ductility
present only slight increases in boron steel, no significant from the quality point of view, however, the
ratio between yield stress and tensile strength in boron steels shown a clear improvement respect to
the standard. Traction tests in samples obtained at the exit of each one of the matrixes used during the
cold drawing process shows an improve in the behavior of low carbon steel with boron contents.
Formation of Microstructure and Texture in Intercritically Rolled C-Mn Steel
Authors: Petrov Roumen H. , Kestens Leo A.I. , Houbaert Yvan
Published: March 2009

Series of trials were conducted on a laboratory rolling mill to evaluate the influence of
intercritical rolling on the microstructure and texture of steel with 0.082%C, 1.54% Mn, 0.35% Si,
0.055%Nb and 0.078%V. Two parallel rolling schedules A and B were designed on the base of the
experimentally deduced CCT diagram of the steel. In rolling schedule A the material was subjected
to accelerated cooling and coiling simulation after final rolling in the intercritical region, whereas in
rolling schedule B the last rolling pass in the intercritical region was replaced by a water quench at
the same temperature of the intercritical rolling pass in schedule A. Microstructure and texture were
characterized by means of light optical microscopy, scanning electron microscopy, EBSD and
XRD.
It was found that the average grain diameter and the texture depend significantly on the final rolling
temperature in the intercritical region. The decrease of the intercritical rolling temperature leads to
an increase of the {111}〈uvw〉 /{001}〈uvw〉 ratio, but at the same time the increase of the average
ferrite grain size was also observed. A phenomenological model based on the K–S orientation relationships
was used to predict the texture formation in the intercritical region.
Ageing Characteristics and Microstructural Evolution in Microalloyed Al Alloys
Authors: Chen Zhi Gang , Zheng Zi Qiao , Zhong Jue , Ringer Simon P.
Published: March 2009

The present paper outlines the effect of small addition of Sc,Ag and Mg on the ageing
characteristics and microstructural evolution in some microalloyed Al alloys,such as Al-Cu-Mg,
Al-Ag and Al-Li alloys.Small quantities of these microalloying elements can modify the ageing
characteristics of these alloys,and significant changes have been found in their microstructural
evolution after small microalloying element additions. The observed effects are explained in terms
of the atomic behaviour during the early ageing stage,and one of the key factors governing this
effect is Sc/Vacancy mechanism.
Advanced High Strength Steels for Automobile Body Structures
Authors: Takahashi M. , Uenishi A. , Yoshida H. , Kuriyama H.
Published: March 2009

There has been a big demand for increased vehicle safety and weight reduction of
auto-bodies. An extensive use of high strength steels is one of the ways to answer the requirement.
Since the crashworthiness is improved by applications of higher strength steels to crashworthiness
conscious structural components, various types of advanced high strength steels have been developed.
The crash energy during frontal collisions is absorbed by the buckling and bending deformations of
thin wall tube structures of the crushable zone of auto-bodies. In the case of side collision, on the
other hand, a limited length of crushable zone requires the components to minimize the deformation
during the collision. The lower the strength during press forming, the better the press formability is
expected. However, the higher the strength at a collision event, the better the crashworthiness can be
obtained. It can, therefore, be concluded that steels with higher strain rate sensitivities are desired.
Combinations of soft ferrite phase and other hard phases were found to improve the strain rate
sensitivity of flow stresses. Bake hardening is also one of the ways to improve the strain rate
sensitivity of flow stresses.
Innovative Annealing Techniques for the Production of Advanced High Strength Steels
Authors: Elgoyhen C. , De Paepe Annick , Lucas A. , Hardy Y.
Published: March 2009

Nowadays, it is not evident to produce in a robust way cold rolled and
annealed/galvanised high strength steels based on lean chemistries and with consistent
mechanical properties over the coil length. The reasons behind this are first the low cooling
rates available on the lines which require the use of a large amount of alloying elements for
avoiding the unwanted phases such as the pearlite and secondly the difficult control of soaking
temperature and time in a narrow range, resulting in a variable austenite content at the end of
the soaking and then in a dispersion of the obtained mechanical properties.
By considering high speed cooling technologies on a compact annealing/galvanizing line, this
production becomes possible. After rapid heating by means of induction heating and short
holding at a high soaking temperature, the strip is cooled down to an intermediate temperature,
where it is held for a short period for obtaining a stable ferrite-austenite structure. Then it is
rapidly cooled by means of cold water (Twice) in the case of a continuous annealing line or by
the zinc quench process in the case of the galvanizing line. These rapid cooling equipments
allow reaching high tensile strength levels with a significant reduction of the addition of
expensive elements (Mn, Cr and Mo).
Effect of Aluminum and Titanium Content on Grain Growth, Texture and Magnetic Properties in 3%Si Non-Oriented Electrical Steel
Authors: Arita Y. , Ushigami Yoshiyuki
Published: March 2009

The effect of annealing temperature on grain growth, texture development and magnetic properties
of Al-free and Al-1% added non-oriented electrical steel were investigated. Normal grain growth
occurred in Al-free steel. On the other hand, abnormal grain growth occurred in Al-added steel which
was annealed at 800°C for 24h. Precipitates in these two steels were different. TiN precipitated in Alfree
steel, but in the case of Al-added steel, AlN and TiC precipitated. The TiC in Al-added steel was
so fine that it inhibited the normal grain growth and finally caused the abnormal grain growth. Main
textures of both steels were near {111}<112>, but the intensity of near {111}<112> in the abnormal
grain growth was higher than that in the normal grain growth. Magnetic flux density (B50/Bs) was
decreased by the grain growth. Especially B50/Bs in the abnormal grain growth was lower than that in
normal grain growth. B50/Bs in these steels can be estimated by their three-dimensional textures in
vector method.
Static Recrystallization of Tool Steels
Authors: Imbert C.A.C. , McQueen H.J.
Published: March 2009

Double-twist torsion tests were used to determine static softening in the hot working range of three
tool steels – W1, a carbon steel (1.03% C - 0.8% other elements), A2 and D2, a medium and a high
alloy steel, containing 8.45% and 14.82% alloying elements. The carbon steel, that was single-phase
austenite in the hot-working range, experienced rapid static recrystallization due to increased
diffusion rate caused by C in hot austenite, very little alloying solute and no carbides. Carbides in
alloy tool steels, which exist throughout the hot-working range, have a retarding effect on the
progress of recrystallization but are responsible for enhancing initiation due to formation of nuclei
at the strain concentration near the particle/matrix interface. Static recrystallization (SRX) of the
alloy tool steels was compared with austenitic stainless steels, with similar strengths but much
greater alloying content, and with microalloyed steels, as well as with the dynamic recrystallization
kinetics.
Prospects and State of the Art of TMCP Steel Plates for Structural and Linepipe Applications
Authors: Schwinn Volker , Schuetz Wolfgang , Fluess Peter , Bauer Juergen
Published: March 2009

Higher strength and higher thickness are ongoing demands on plates for pipes and
structural applications. At the same time other properties like toughness and weldability must be
kept or even be improved. As a consequence these demands must be achieved with limited addition
of alloying. Specific aspects must be incorporated in the design of thick plates. To exploit the
mechanisms of property achievement effectively and to compensate certain disadvantages of thick
plate production appropriate mill equipment is necessary. Utilization of TMCP provide the basis to
meet these goals.
The Ultrahigh Ductility of an Ultrahigh Carbon Steel Containing 3%Si
Authors: Ruano Oscar , Oyama Toshi , Sherby Oleg D.
Published: March 2009

Superplastic properties of fine-grained ultrahigh carbon steels (UHCS) have been
greatly improved through the addition of 3 wt% Si (UHCS-3Si) and through improved processing
conditions. This material showed an elongation to failure of 1300% under optimum superplastic
conditions. It is also superplastic at very high strain rates, i.e. 10-2 s-1, in the temperature range
between 800 and 825°C. An analysis of the effect of silicon additions on the UHCS and the
influence of the introduction of temperatures regions in the phase diagram on the superplastic
properties is made.