bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of Ti50-Pd(50-x)-W(x) High Temperature Shape Memory Alloy
Authors: Nakayama Hiroyuki , Taya Minoru
Published: March 2009

Characteristics of high temperature shape memory alloy in Ti50-Pd(50-x)-W(x) at%, x =
3 and 5 system has been examined. The prepared ingot was homogenized at 1273 K for 86.4 ks
followed by water quenched. The homogenized samples were hot-rolled at 1273 K to a plate shape
with thickness of 3.5 mm and 1.0 mm. Transformation temperatures were determined by 4-probe
electrical resistivity measurement. The transformation behavior in the both samples exhibited
similar trend. The first heating curve showed no significant step. In contrast, the first cooling curve
exhibited clear step due to martensitic transformation. After second cycle, the transformation
behavior was stabilized, thus the clear steps in the cooling and heating curves were seen. Stressstrain
curve of hot-rolled plate with 3.5 mm was examined by compression in Ti50-Pd47-W3 at%
alloys. The sample exhibited 1 % shape memory effect. By bending test, nearly perfect SME effect
was observed in hot rolled Ti50-Pd45-W5 at% alloy plate with thickness of 1 mm.
Equal Channel Angular Extrusion (ECAE) of Ni-Ti Based Shape Memory Alloy Systems
Authors: Yu Chin Jye , Lei Chiang Shu , Mahapatra Rabindra , Sharp Jeff , Karaman Ibrahim
Published: March 2009

In this paper we report the effects of Equal Channel Angular Extrusion
(ECAE) processing on the phase transformation characteristics of Ni-Ti based shape
memory alloys in terms of transformation temperatures, temperature hysteresis, and
microstructural evolution. The ECAE process affects the material’s shape memory
behavior via microstructural refinement. Differential Scanning Calorimetry (DSC)
and Transmission Electron Microscopy (TEM) were utilized to investigate the effects
of microtructural refinement and substructure formation on the shape memory
behavior of these alloys. The microstructural refinement was found to have
significant influence on the transformation temperatures.
Ti-Ni Shape Memory Alloy Film Cantilever Actuator for Micro-Probing
Authors: Namazu Takahiro , Okamura Y. , Tashiro Y. , Inoue Shozo
Published: March 2009

This paper describes novel MEMS probe card device, which is composed of silicon (Si)
cantilever beams actuated by titanium-nickel (Ti-Ni) shape memory alloy (SMA) films. Since Ti-Ni
SMA film can yield a higher work output per unit volume, Ti-Ni film-actuated Si cantilever beam is
expected to be a MEMS probe card device providing large contact force between probe and electrode
pad. The developed cantilever beam produces a contact force by not only cantilever bending in
contact but also the shape memory effect (SME) of Ti-Ni film arising from Joule’s heating. The SME
of Ti-Ni film containing Ti of 50.5 atomic (at.) % to 53.2 at. % can generate an additional contact
force of 200 μN on average under applying an electric power of 500 mW to the film. Ti-Ni
film-actuated Si cantilever beam would be a key element for successful MEMS probe card with larger
contact force and smaller size.
Recent Advances in Microwave and Millimeter-Wave Processing of Materials
Authors: Lewis III D. , Imam M. Ashraf , Fliflet Arne W. , Bruce Ralph W. , Kurihara L.K. , Kinkead A.K. , Lombardi M. , Gold Steven H.
Published: March 2009

We are using 2.45 GHz (S-Band) microwave systems and an 83-GHz, gytrotron-based,
millimeter-wave beam system in material processing and other areas. We use one 2.45 GHz system
in preparation of nanophase metals, metal mixtures and metal oxides, via the patented continuous
microwave polyol process, with potential for large scale, low cost production. Of interest are
precious metals, mixtures of magnetic and nonmagnetic metals, and mixed metal oxides for ceramic
precursors. The other S-Band systems are used to develop repair techniques for ceramic matrix
composites where the repairs are heated to 200-1000°C. A portable, battery-powered system is
being developed for field repairs, and promises to be much more practical than alternative
approaches (e.g., heating blankets). The 83-GHz system is being used in rapid sintering of
polycrystalline ceramic materials intended for use in high power solid state lasers, where the
requirement if for sintering to transparency with high optical quality and good lasing efficiency.
Transparent Yb-doped yttria has been produced with hybrid conventional/millimeter-wave sintering
of nanophase powders, as well as theoretically dense YAG. Another application for the millimeterwave
beam system is in consolidation and bonding of hard coatings to light alloys, such as SiC on
titanium, where the beam system allows heating of the coating to very high temperatures without
overheating the metallic substrate. Finally, the millimeter-wave system is being used in the
development of millimeter-wave plasma-assisted diamond deposition, where the quasi-optical
system has significant advantages over conventional microwave plasma-assisted diamond
deposition. Results for these various areas will be presented and discussed.
Pitting Corrosion Behavior of Sintered SUS444 Stainless Steel in MgCl2 Solution
Authors: Sunada Satoshi , Miyazaki Yusuke , Majima Kazuhiko
Published: March 2009

The pitting corrosion behavior of sintered SUS 444 stainless steels (P/M specimens) with
different kinds of porosity ratios of 13.3, 9.11 and 6.88 % was studied in an aqueous solution
containing MgCl2 compared with a conventionally processed SUS 444 stainless steel(I/M
specimen). The pitting corrosion potential decreased almost linearly as porosity ratio increased, and
the I/M specimen showed the best resistance against the initiation of pitting corrosion. The pitting
corrosion morphology by SEM observation showed that more small pits were observed on the
specimen with larger porosity ratio while less number but larger diameter pits were observed on the
specimen with smaller porosity ratio, and it was also confirmed that the I/M specimen had the least
number but the largest and deepest pits.
Texture and Creep Anisotropy in Zirconium Alloys
Authors: Charit Indrajit , Linga Murty K.
Published: March 2009

Zirconium (Zr) alloys are best known for their use in nuclear reactor applications. A
hexagonally close-packed structure with a low c/a ratio and very limited slip systems leads to strong
textures in these alloys during fabrication processes. These alloys are used in cladding applications
for encapsulating fuel pellets, and undergo various stress conditions in-service. Hence, it is
necessary to understand the creep properties of Zr alloys to predict the life of reactor claddings. Due
to the unique texture, the creep deformation of these alloys is anisotropic in nature. The texture of
Zircaloys was determined by X-ray diffraction experiments, and expressed in terms of pole figures
and crystalline orientation distribution functions. Biaxial creep testing of thin walled tubing was
used to study the creep anisotropy. Creep loci evaluation based on the experimental data and model
predictions are compared. It is found that the models can predict the creep loci for recrystallized
alloy very well. However, they fail to explain the behavior of the cold worked alloys. When stress
enhancements due to the grain boundary sliding are taken into account, the predicted creep loci
correlated well with that constructed from the experimental data.
Methodology for Automatic Control of Automotive Al-Si Cast Components
Authors: Krupiński Mariusz , Dobrzański Leszek Adam , Sokolowski Jerry , Kasprzak Wojciech , Byczynski Glenn E.
Published: March 2009

Computer based classification methodology is presented in the paper for defects being
developed in the Al alloys as the car engine elements are made from them produced with the
vacuum casting method. Identification of defects was carried out using data acquired from digital
images obtained using the X-ray defect detection methods. The developed methodology as well as
the related X-ray image analysis and quality control neural networks based software were carried
out to solve this problem.
Website Publication of Calculation Computer Program and Visualized Pieces both of Bcc and Fcc Pencil Glide Theory for Deformation Texture
Authors: Masui H. , Katoh H.
Published: March 2009

Theories of the pencil glide theory for bcc metal and MPG(modified pencil glide) theory
for fcc metal are reviewed. Interest is focused to both analogy and difference in derivation of the
theories. Some visualization figures using them are introduced. At last, it is informed that the
authors have opened both the bcc pencil glide theory and MPG(fcc) theory on website publication
which calls everybody to look and download the fundamentals, applications, visualization ,
procedure of calculation and C program for calculation for the both pencil glide theories.
Microstructure and Texture Evolution during Annealing after Temper Rolling of a 2 wt.-% Silicon Electric Steel
Authors: Lima Liana M.F.G. de , Lima Nelson B. , Plaut Ronald Lesley , Padilha Angelo Fernando
Published: March 2009

The evolution of the microstructure, macrotexture, microtexture and mesotexture
has been studied during the annealing at 760°C after temper rolling (9% thickness
reduction) of a non-oriented electrical steel sheet containing 2 wt. % Si. Results showed
that the coarse grained microstructure, obtained on annealing, is produced through a
recrystallization mechanism that advances from the surface to the interior of the sheet.
However, starting of this process is delayed due to the presence of Si. The majority of
experiments carried out in this work have been repeated for a low-carbon steel (C = 0.0385;
Mn = 0.18%) containing only 0.03% Si and the results obtained were practically identical
to those observed in the steel containing 2% Si. The main difference observed between
both steels was that the process of formation of the exaggeratedly large grains was slower
in the steel containing 2% Si.
Microstructure and Gas Sensing Property of Porous SnO2 Sputtered Films
Authors: Yamazaki Toshinari , Jin Cheng Ji , Shen Yan Bai , Kikuta Toshio , Nakatani Noriyuki
Published: March 2009

It is often said that the sensitivity of a gas sensor made of an oxide semiconductor film
is enhanced by making the film porous. However, the porosity of sensor films has not been
sufficiently examined. In this study, SnO2 films were deposited using DC magnetron sputtering
under various substrate temperatures and discharge gas pressures. In addition to the structural
analysis by means of X-ray diffraction and scanning electron microscopy, the density and the BET
surface area were measured to clarify the film porosity. The sensitivity to H2 gas of undoped and
Pd-doped SnO2 films upon exposure to 1000 ppm H2 was measured at 300 . SnO2 films
generally showed a columnar structure. The film deposited at a low temperature and a high pressure
showed a low density and a large effective surface area. The H2 sensitivity increased as the density
decreased, that is, as the effective surface area increased.
Measuremet of Mechanical Properties of Thin Films and Nanostructured Materials at High Spatial Resolution
Authors: Bull S.J.
Published: March 2009

The development of nanostructured materials and coatings has driven the development of
indentation-based assessment techniques which aim to generate useful mechanical property
information. This paper introduces an approach to determine the limits for which direct
measurement of these properties are possible and highlights the importance of modelling if
reliable data is to be obtained from very thin coatings (<200nm) and fine grained materials.
Development of New Actuators for Flapping Wing Flight
Authors: Chung Dong Teak
Published: March 2009

Flying robots with flapping wings are preferred over conventionally fixed or rotational wings in
terms of hovering capability for a simple mechanical configuration. Until recently, available
actuators for such a robot are limited to (1) a conventional motor with four-bar linkage mechanism
or (2) a piezo electric actuator, but none of them could provide enough lift because of low flapping
frequency, small stroke angles, and/or frequent mechanical failure. A new actuator capable of
generating large stroke angles with high frequency is developed. It consists of an out-runner
brushless motor with a modified motor driver attached to a torsion spring. The wing is attached
directly on the cap of the motor. A prototype is built and preliminary thrust force measurements are
performed. Properties of wing materials suitable for powerful and robust actuators will be
discussed. The actuator employed in the present study utilizes resonance oscillation, which leads to
high energy efficiency. Further study of wing shape and directional stiffness is needed for
generating higher lift capability.
Friction Stir Processing of Cast NiAl Bronze
Authors: Mahoney Murray W. , Fuller Christian B. , Bingel William H. , Calabrese Michael
Published: March 2009

Friction stir processing (FSP) of cast NiAl bronze has resulted in
significant increases in properties including more than doubling the yield greater that
40 percent increase in the threshold fatigue life; all achieved while increasing
ductility. These and other strength, greater than a 60 percent increase in tensile
strength, and property improvements were realized following studies of FSP
procedures specifically for NiAl bronze. Within this manuscript, FSP procedures and
other “lessons learned” are presented. Details of property improvements are
documented elsewhere within this conference proceedings (see Fuller et al.).
Presented herein are tool designs for efficient material flow, tool materials capable of
long life at 1000°C, rastering procedures covering large surface areas, and other
results pertinent to achieve improved properties in cast NiAl bronze following friction
stir processing.
Residual Strain Measurements in a Friction-Stir Processed AZ31B Magnesium Alloy Using Neutron Diffraction
Authors: Woo W. , Choo Hahn , Brown Donald W. , Clausen Bjørn , Feng Zhi Li , Liaw Peter K.
Published: March 2009

Residual strain profiles in friction-stir processed (FSP) AZ31B magnesium-alloy plates were
measured using neutron diffraction. Two different specimens were prepared to investigate the
influences of the tool shoulder and the tool pin on the residual-strain profiles: (Case 1) a plate
processed with both the stirring pin and tool shoulder, i.e., a regular FSP plate subjected to both the
plastic deformation and frictional heating, and (Case 2) a plate processed only with the tool
shoulder, i.e., subjected mainly to the frictional heating. The results show that the strain profiles of
both cases are qualitatively quite similar. The longitudinal strain is mainly tensile with its
maximum near the bead of the FSP plate. On the other hand, the transverse and normal strains are
mildly compressive in both Cases 1 and 2.
Transient Local Melting in Al 7075-T6 Friction Stir Spot Welds
Authors: North T.H. , Bendzsak G.J. , Gerlich A. , Su P. , Cingara G.
Published: March 2009

Transient local melting can account for the remarkable decrease in the strain rate when the
tool rotational speed, heating rate and cycle time produce temperatures exceeding the 475
°C in Al 7075-T6 spot welds. The calculated strain rate is about 20 s-1 in Al 7075-T6 spot
welds produced using tool rotational speeds from 1500 RPM to 3000 RPM and dwell time
of 4 s. However, the peak temperature is less than less than 475 °C when a low tool
rotational speed setting (1000 RPM) is used; transient local melting and tool slippage are
precluded and the calculated strain rate is high (about 650 s-1). It is proposed that transient
local melted films directly influence formation of the stir zone microstructure in Al 7075-
T6 spot welds. It is suggested that the stir zone microstructure in spot welds made using
high tool rotational speed settings are determined by a combination of grain boundary
sliding and the limitation of cavity interlinkages when transient local melted films form.
Influence of Contineous Transversal Inclination of Tool on FSW Joints
Authors: Oki Sachio , Takahara H. , Okawa Y. , Tsujikawa Masato , Marutani Yoji , Higashi Kenji
Published: March 2009

The influence of roll angle of the FSW tool rotation axis on tensile properties of joints was
examined to clarify the allowance of deviation from proper tool posture for three-dimensional
friction stir welding. A5083-O plates of 3 mm in thickness were butt welded by three-dimensional
controlled FSW machine. Transversal inclination of the tool (roll angle of the tool) was continuously
changed from 0 degrees to 10 degrees for both sides. Butt joints ruptured at base metal within the
range of roll angle of the tool plus/minus 2 degrees, and ruptured at the thin part made by inclined
tool shoulder entering in the range by plus/minus 7 degrees. Over the range of plus/minus 7 degrees,
butt joints ruptured at elongated cavities made by tool inclination at the border of stir zone and base
material.
Solid State Welding between CPTi and AZ31B Magnesium Alloy by Friction Stirring
Authors: Tanabe H. , Watanabe Takehiko , Abe Y. , Yanagisawa A.
Published: March 2009

This paper described an experimental study on the friction stir welding of dissimilar
metal between commercially pure titanium (CPTi) and magnesium alloy AZ31B (Mg). Butt-welds
produced at various tool rotation speeds were evaluated by the observation of the weld surface
appearance, X-ray radiographic test, tensile test, SEM and EDX analysis. The main results obtained
are as follows. Butt-joint welding of the CPTi plate to the Mg plate was easily and successfully
achieved. The ignition of Mg occurred during welding at the tool rotation speeds over 1200rpm.
The fragments of CPTi existed in a continuous form in Mg matrix. The tool rotation speed of
1200rpm attained the maximum tensile strength of a joint, which was about 75% of that of Mg base
metal. Fracture occurred at the weld interface in most joint. EDX analysis revealed that Al in the
Mg diffused into CPTi through the weld interface and MgO existed at the interface. It seems that
the decrease in Al concentration in the Mg and MgO formation around the weld interface caused the
low tensile strength of the joints.
Formation of Intermetallic Compounds in Friction Bonding of Al Alloys to Steel
Authors: Yamamoto Naotsugu , Takahashi Makoto , Aritoshi Masatoshi , Ikeuchi Kenji
Published: March 2009

The microstructure of the friction-bonded interface of Al alloys to low C steel
has been investigated by TEM observations to reveal the controlling factor of the
formation and growth of the IMC (Intermetallic Compound) layer, which caused the
premature fracture at the interface even when its thickness was less than 1 μm, as
reported in a previous paper. The thickness of the IMC layer observed at the interfaces
of Al-Mg alloy/steel and pure-aluminum/steel joints increased almost in proportion to
the friction time, but did not obey the parabolic law a characteristic kinetics of the
diffusion-controlled process. Analyses of SAD patterns from the IMC layer indicate that
it consisted of Fe2Al5, Fe4Al13, (Fe, Mn)Al6 and FeAl2, depending on the alloying
elements. These IMCs were granular and distributed almost randomly within the IMC
layer, suggesting that mechanical mixing of the steel with the Al alloy occurred at the
interface. In the low C steel adjacent to the IMC layer, a zone of much finer grains than
those of the base metal was observed. Its width increased with friction time and pressure,
and with the growth of the IMC layer, as well. These results suggest that the superficial
region of the steel underwent a heavy plastic deformation during the friction process
and it had a close relation with the growth of the IMC layer.
Alloying with Silicon and Copper in Aluminum Alloys
Authors: Mackay Robert , Hausenbusch Ron , Sokolowski Jerry
Published: March 2009

The main aim of the metallurgical investigation was to enhance our understanding
of the role Cu and Si have on the development of shrinkage porosity in the as-cast structure,
which in turn can affect high cycle fatigue (HCF) properties of Al-9Si-1Cu (W328) and Al-
7Si-4Cu (W319) alloys. In order to achieve this objective a novel approach using thermal
analysis and calculated fraction solid techniques was developed to assess mushy zone
kinetics, the state between the liquidus and solidus where a solid skeletal α-Al phase and the
Al-Si eutectic phase grow at the expense of an inter-dendritic liquid. Specifically, the cooling
curve and calculated fraction solid curve were partitioned into segments, which reflect
different stages of feeding through the entire solidification event of the alloy. Each partitioned
segment corresponds to a stage of feeding, which in turn signifies a relative degree of pore
growth susceptibility. Two thermal analysis techniques, both using calibrated thermocouples,
were used to precisely understand the solidification path for both the W319 alloy and the
W328 alloy.
Microstructure and Properties of High Strength Weld Metals
Authors: Svensson Lars Erik
Published: March 2009

The recent investigations about high strength manganese – nickel alloyed weld metals
are reviewed. The mechanical properties from different alloying concepts and the
associated microstructures are compared. Interesting similarities regarding the tensile
and impact strength is noted, while large variations in microstructure is found.
Liquation Cracking in Aluminum Welds
Authors: Huang C. , Cao G. , Kou Sindo
Published: March 2009

Liquation cracking in the partially melted zone (PMZ) of aluminum welds was studied.
The PMZ is the region immediately outside the fusion zone where the material is heated above the
eutectic temperature. Highly crack-susceptible alloys 2024 and 7075 were welded using gas-metal
arc welding (GMAW) with filler metals 1100 and 4043, respectively. Circular-patch welds were
made on 3.2 mm thick workpiece with full penetration, and single-pass welds were made on 9.5
mm thick workpiece with partial penetration. Liquation cracking was observed in all welds. Dualpass
welds were also made on 9.5 mm thick workpiece, with overlapping between the penetration
tips of the two partial-penetration passes made on the opposite sides of the workpiece. Liquation
cracking was found in the first pass but not in the second pass. The results were explained using TfS
(temperature vs. fraction solid) curves of the weld metal (WM) and the PMZ based on the
following criterion proposed recently: liquation cracking can occur if WM fS > PMZ fS during PMZ
solidification.
Micro-Resistance Spot Welding of Nickel Free Austenitic Stainless Steel
Authors: Fukumoto Shinji , Matsuo Taiju , Kuroda Daisuke , Tsubakino Harushige
Published: March 2009

Micro-resistance spot weldability of nickel free stainless steel sheet was studied to fabricate
medical implants. Weld lobe was established and the effect of welding parameters on joint strength
was investigated. Weld nugget represented a rapidly quenched austenitic cellular structure whose cell
size is several μm with a little ferrite. The amount of δ-ferrite in weld nugget is smaller than that
predicted by some Schaefller diagrams due to rapid solidification during micro-resistance spot
welding.
Surface Hot-Shortness of Steels Induced by a Small Amount of Copper and Tin from Scrap Steels and its Suppression Methods
Authors: Kunishige Kazutoshi , Hatano Masaharu
Published: March 2009

The recycling of scrap steels can be difficult due to the tramp elements that they can
contain. During the steelmaking process, tramp elements such as Cu and Sn are difficult to be
removed; and it is these elements that cause surface cracking of steels during hot rolling process
(i.e. Cu and Sn liquid embrittlement).The paper consists of three different experiments into the
suppression of surface cracking during the hot rolling process. For the oxidation in air, the surface
cracking most severely occurred in the specimens which were oxidized around 1100°C in the tested
range of 950-1200°C after a 1250°C heating. For the change in oxidation atmosphere from air to
water vapor, the surface cracking occurred more severely although the mass gains were smaller in
water vapor than in air oxidation. For the addition of Si and Ni in the water vapor conditions of
0%-30%H2O, the surface cracking was found to be suppressed effectively when the mass gain
increased. The Cu and Sn enriched alloys at the scale/steel interface were closely observed by
optical microscopy and scanning electron microscopy. The mechanism for suppression of the
surface cracking was explained in terms of back diffusion of Cu and Sn into the steel and/or
occlusion of Cu and Sn into the scale through the development of a rugged scale/steel interface.
Experimental Studies into Strip Casting of Steel
Authors: Phelan Dominic , Zuidwijk T. , Strezov L. , Sietsma Jilt , Dippenaar Rian
Published: March 2009

The strip casting of steel, whereby liquid steel is solidified between twin water cooled copper rolls
directly into its final shape, is a radical, energy efficient, cost effective route for the production of
steel products that also provides exciting opportunities for the development of new products. An
experimental program is currently underway to study phenomena associated with rapid
solidification of steel using levitating droplet techniques and Gleeble®3500 thermo-mechanical
processing. For example, studies have been conducted to investigate the heat transfer, nucleation
behaviour and microstructure development during solidification of a low carbon steel and a
peritectic steel on copper substrates hard coated electrolytically or using Filtered Arc Deposition
(FAD). It was found that peak and average heat fluxes were significantly higher for steels solidified
on the first substrate than for the FAD coated substrates. Maximum heat flux on the respective
substrates was 36.5 to 39.0 MW/m2 and 8.3 to 9.4 MW/m2. The average heat flux on the respective
coated substrates ranged between 9.6 to 12.5 and 5.5 to 6.6 MW/m2.
Effect of Heat Treatment on the Structure and Morphology of Amorphous Steel Produced Using Spray Metal Forming
Authors: Rao A. Srinivasa , Kohler L. , Aprigliano L.F.
Published: March 2009

In order to investigate the effect of heat treatment on the structure and
morphology of spray formed structurally amorphous steel, several small samples were cut
from one spray formed amorphous steel ingot (DAR – 35). The samples were heat treated
at 700oC in a tube furnace under a constant flow of 99.9% argon for up to 120 hours. The
samples were furnace cooled to 300oC. Later they were quenched in water. The
structure was investigated using x-ray diffraction and the morphology of the polished and
lightly etched samples was examined under both optical and scanning electron
microscopes. The results indicate that the spray formed steels were amorphous.
However, their microstructure is not homogeneous. The microstructure is composed of
three distinctively different phase contrasts (viz. light gray, dark gray and bright white
contrasts). The bright white phase contained maximum amount of tungsten and
molybdenum, it had the least amount of iron. Both light and dark gray phases contained
nearly the compositionally expected amount of iron, and more chromium than
compositionally expected. The effect of heat treatment at 700oC had no effect on the
three different phase contrasts. However, the heat treatment at 700oC showed some
effect on the crystallization of the structure. The heat treatment for up to 24 hours has
very little effect on the structure and morphology of the amorphous steel samples.
However, if the samples were heat treated at 700oC for more than 24 and below 72 hours,
it appears that a partial crystallization of the steel occurs. Significant crystallization of the
spray formed amorphous steel occurs due to prolonged heat treatment above 72 hours.
Constitutive Modeling of Stress-Strain Curves of IF Austenite
Authors: Lino Roney Eduardo , Barbosa Ronaldo
Published: March 2009

Industry hot deformation processes such as hot rolling are complex in nature. Setting up
a rolling mill requires precise knowledge of the loads needed to shape the metal. This in turn,
demands the ability to predict the strength of the material when deformed to a value of strain and
strain rate at a given temperature. On and off-line models need, however, to be fed with
constitutive equations relating the stresses required to deform a certain metal under the usual
process variables. This paper shows how a set of stress-strain curves can be modeled so that both
hardening and softening mechanisms commonly present during hot deformation are taken into
account. The model predictions are compared to a set of literature data in order to be validated.
Reasonable agreement between published results and predicted values were obtained indicating
how efficiently the model can assess values of stresses under hot working conditions.
Effect of the Annealing Conditions on the Microstructure and Mechanical Properties of a 0.04% C Al Killed Steel
Authors: Cardozo Jacobo J. , Rivas A.L. , Colas R.
Published: March 2009

The present investigation evaluates the effect of static annealing variables on the grain
structure and mechanical properties of a 0.04 %C-Al killed steel. The experimental variables
selected were the heating rate and the initial heating temperature. The results showed that an
increase in the initial heating temperature and heating rates inferior to 500°C and 100°C/h,
respectively, do not have a major influence in the grain structure of the material. These annealing
conditions lead to a full "pancake" type of microstructure of the recrystallized ferrite grain, and as
consequence, the mechanical properties of the material are in the intervals required for deep
drawing applications.
Robust Trimming of Automotive Panels
Authors: Golovashchenko S.F.
Published: March 2009

Small pieces of metal are generated during trimming of automotive body panels.
Commonly referred to as slivers, these pieces can be imprinted into the surface of stamped panels.
This may require metalfinish of every stamped exterior panel. The objective of the paper is to study
the influence of trimming conditions on quality of trimmed surface and to modify the trimming
process to eliminate slivers and burrs from the trimmed surface. Suggested solution includes two
measures: 1) building an elastic support of the offal eliminating bending of the area of the blank
being trimmed off; 2) creating the preference of crack propagation from the lower shearing edge by
machining a small radius on the upper shearing edge.
Determination of Inclusions of Boron and Titanium in Steel by Original Position Statistic Distribution Analysis Technique
Authors: Li Dong Ling , Wang Hai Zhou
Published: March 2009

A new method for the determination of inclusions of boron and titanium in medium and
low alloy steel has been reported in this paper. The technique of original position statistic
distribution analysis based on statistic analysis of more than ten thousands primary optical signals is
applied in the present method. It is found that the abnormal high intensities in emission lines of
boron and titanium occurred when a discharge volatilizes the material containing inclusions of
boron and titanium. Some statistic algorithms are developed to distinguish the signals related to
nonmetallic inclusions from the signals generated from soluble boron and titanium. Furthermore,
mathematical models based on the relationship between the frequency of abnormal sparks and
content of inclusions is put forward in this paper to count the contents of inclusions of boron and
titanium. The results calculated by the present model have good coincidence with the value
obtained by chemical methods. The present method has been applied to the determination of the
contents of inclusions of boron and titanium in some certified reference materials and some real
medium and low alloy steel samples.
Characterization of Metallurgical Transformations in Multi-Phase High Strength Steels by Barkhausen Noise Measurement
Authors: Hug-Amalric Aurélie , Kleber Xavier , Merlin Jacques , Petitgand Hélène , Meilland Philip
Published: March 2009

The potentialities of using the magnetic Barkhausen noise measurement in
characterization of metallurgical transformations have been highlighted in multi-phase High
Strength (HS) steels. This kind of steels are composed of different metallurgical constituents, such
as ferrite, bainite, martensite or residual austenite. Recently, we found that it was possible to assess
the proportion of phases in ferrite-martensite steels and in industrial Dual-Phase steels too. In this
work, we show that the Barkhausen noise measurements can be also suitable to follow bainitic
transformation in a TRIP steel.
Effect of Initial Processing on the Microstructure-Property Relationships in Bake-Hardened C-Mn-Si TRIP Steels
Authors: Timokhina Ilana B. , Pereloma Elena V. , Hodgson Peter
Published: March 2009

The effect of pre-straining (PS) and bake-hardening (BH) on the microstructure and
mechanical properties has been studied in C-Mn-Si TRansformation Induced Plasticity (TRIP)
steels after: (i) thermomechanically processing (TMP) and (ii) intercritical annealing. The steels
were characterised before and after PS/BH by transmission electron microscopy (TEM), X-ray
diffraction (XRD), and tensile tests. The main microstructural differences were the higher volume
fraction of bainite and more stable retained austenite in the TMP steel. This led to a difference in the
strain-hardening behavior before and after BH treatment. The higher dislocation density in ferrite
and formation of microbands in the TMP steel after PS and the formation of Fe3C carbides between
the bainitic ferrite laths during BH for both steels also affected the strain-hardening behavior.
However, both steels after PS/BH treatment demonstrated an increase in the yield and tensile
strength.
Development of Seamless Pipes with Improved Strength-Toughness Combination for Hydraulic Cylinders
Authors: Guarnaschelli Claudio , Folgarait P. , Paravicini Bagliani E. , Demarchi R. , Desimone H.
Published: March 2009

Steel pipes for hydraulic cylinders have to offer high strength levels and good toughness.
A minimum value of 27 J at – 20 °C is typically requested. In this work, a comprehensive
experimental activity based on both laboratory tests and industrial trials was performed in order to
investigate the benefits related to the development of multi-phase microstructures in seamless pipes
for hydraulic cylinders. The effect of these microstructures on strength and toughness were
analyzed. Charpy V-notch (CVN) impact tests showed that toughness increases monotonically with
the increase of the intercritical temperature, i.e. when the carbon content of the newly formed
austenite is reduced. Industrial trials were performed on tubes applying a proper inter-critical
quenching. The product after cold drawing and stress relieving achieved high yield strength values
and showed an excellent toughness, even at – 40°C, in both the transverse and longitudinal
directions.
Crystallography and Mechanical Properties of Ultrafine TRIP-Aided Multi-Phase Steels
Authors: Wakita Masayuki , Adachi Yoshitaka , Tomota Yo
Published: March 2009

This study aims at examining thermomechanical controlled process to realize ultrafine
TRIP-aided multi-phase microstructures in low carbon steels. Heavy deformation at a supercooled
austenite region was found to lead the formation of 2 μm ferrite as well as retained austenite with
high volume fraction. The morphology of retained austenite was changed from film-like shape to
granular shape with lowering finish rolling temperature in austenite field. This ultrafine TRIP-aided
multi-phase steel showed good balance of tensile strength with total elongation, ie. 1080MPa and
26.9%. A novel in-situ neutron diffraction measurement demonstrated that the retained granular
austenite transformed to martensite at a relatively large strain compared with the retained film
austenite. The therein-underlying mechanism of the good mechanical properties was discussed from
the view points of the morphological and thermodynamical stabilization of retained austenite.
State-of-Art High Strength Steel Sheets for the Automotive Application
Authors: Urabe Toshiaki , Kitano Fusato , Fujita Takeshi , Yamasaki Yuji , Hosoya Yoshihiro
Published: March 2009

New type of IF cold-rolled high strength steels (HSSs) with the strength level of 390 and
440MPa have been developed under the chemistry of the extra-low carbon steel containing around
60ppm C with an intentional addition of niobium by hybridizing the precipitation hardening with
niobium carbides and the supplemental solid-solution hardening. In this steel, Precipitation Free
Zone (PFZ) nearby recrystallized grain boundaries forms during continuous annealing. This structure
leads to unique mechanical properties such as lower yielding and superior anti-secondary-work
embrittlement under fine grain structure strictly required for the exposed panels in Body-in-White.
Principles of the unique mechanical properties of the steel are introduced related with the formation of
PFZ during annealing, and the results of further approach to improve them as the state-of-the-art
product, which is widely used for the exposed panels in Body in White, are introduced in the paper.
Effect of Processing Route on Mechanical Behavior of C-Mn Multiphase High Strength Cold Rolled Steel
Authors: Santos Dagoberto Brandão , Neves Élida G. , Pereloma Elena V.
Published: March 2009

The multiphase steels have complex microstructures containing polygonal ferrite,
martensite, bainite, carbide and a small amount of retained austenite. This microstructure provides
these steels with a high mechanical strength and good ductility. Different thermal cycles were
simulated in the laboratory in order to create the microstructures with improved mechanical
properties. The samples were heated to various annealing temperatures (740, 760 or 780°C), held
for 300 s, and then quickly cooled to 600 or 500°C, where they were soaked for another 300 s and
then submitted to the accelerated cooling process, with the rates in the range of 12-30°C/s. The
microstructure was examined at the end of each processing route. The mechanical behavior
evaluation was made by microhardness testing. The microstructural characterization involved
optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) with
electron backscattering diffraction (EBSD) and transmission electron microscopy (TEM). The use
of multiple regression analysis allowed the establishment of quantitative relationship between the
microstructural parameters, cooling rates and mechanical properties of the steel.
Microstructure Model for a Dual-Phase Steel
Authors: Liu Dong Sheng , Militzer Matthias , Poole Warren J.
Published: March 2009

The microstructural evolution has been studied for hot rolling of a dual-phase steel with a lean
C-Mn-Si chemistry. This study includes the investigation of austenite grain growth during
reheating, constitutive behaviour and static recrystallization kinetics of austenite, and austenite
decomposition during simulated run-out table cooling conditions. To develop and validate the
microstructure models for these phenomena, experimental studies have been carried out in the
laboratory using a Gleeble 3500 thermomechanical simulator. The hyperbolic sine relationship
between flow stress and Zener-Hollomon parameter is employed to describe the constitutive
behaviour. The Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory is used to predict the static
recrystallization kinetics. Ferrite transformation start is described with an approach that
considers early growth of corner nucleated ferrite. The fraction of ferrite transformed from
austenite during continuous cooling is described using the JMAK approach in combination with
the additivity rule. The ferrite grain size is quantified as a function of the transformation start
temperature. The overall microstructure model has been validated based on a number of
laboratory simulations of the entire hot strip rolling and controlled cooling process with an
emphasis on industrially relevant run-out table cooling strategies.
Effects of Heat Treatment and Composition Modification on SAE 8620 Steels
Authors: Hong Steven , Lin H.C. , Yang C.H. , Tseng L.Y. , Lin K.M.
Published: March 2009

The effects of quench-tempering treatment and composition modification on SAE 8620
steels have been investigated. Experimental results show that the 400°C tempering of SAE 8620
steels can exhibit an excellent overall performance, including the mechanical strength, impact
toughness and corrosion resistance. By slightly adding alloy elements into SAE 8620 steels, the
modified HSLA steels exhibit excellent hardenability, high mechanical strength and elongation, and
ductile fracture behavior. These excellent performances are comparable to those of HSLA-100
steels and can satisfy well the requirement of Grade 100 lifting components.
The Characterisation of Oxide Scales Grown on Nickel Containing Steel Substrates Using Electron Backscatter Diffraction
Authors: Higginson Rebecca L. , West G.D. , Jepson M.A.E.
Published: March 2009

The oxidation of steels is critically influenced by its constituent alloying elements. These alter the
classical three-phase model of the external oxide scales and in addition can introduce internal
oxidised regions. This paper considers the oxidation of a number of nickel containing Fe based
alloys of varying compositions, including stainless steel. These have been oxidised under different
conditions to produce a number of scale morphologies, which have been characterised using two
SEM based techniques; Electron Backscatter Diffraction (EBSD) and Energy Dispersive x-ray
Spectroscopy (EDS). Results have shown that nickel promotes the formation of a fibrous internal
scale, consisting of iron oxide particles (or iron/chromium oxide in the case of stainless steel)
along grain boundary regions. Nickel is rejected from these oxide particles and consequently
nickel content is enriched in neighbouring metallic areas.
Three-Dimensional Observation and Growth Kinetics of Proeutectoid Ferrite Formed at Austenite Grain Boundary in a Low Carbon Microalloyed Steel
Authors: Wu Kai Ming , Guo A.M. , Cheng Lin
Published: March 2009

Three-dimensional observations of proeutectoid ferrite formed at grain boundary in an
Fe-0.09%C-1.48%Mn vanadium microalloyed alloy was revealed by techniques of serial sectioning
along with computer-aided reconstruction. The ferrite allotriomorphs nucleated at grain boundary edges
were approximately prolate ellipsoids. Not all the ferrite allotriomorphs formed at grain boundary faces
were oblate ellipsoids. The growth kinetics of ferrite allotriomorphs nucleated at grain boundary edges
was greater than that of ferrite allotriomorphs nucleated at grain boundary faces.
Nanocrystallization of Bulk Steels through γ/α Transformation
Authors: Du Lin Xiu , Xiong Ming Xian , Liu Xianghua , Wang Guo Dong
Published: March 2009

A method of obtaining nanocrystallized bulk steels through phase transformation was
investigated. Firstly, the austenite grain size of a microalloyed steel was refined to 1~3μm through
repeatly heating and quenching; secondly, the samples with ultrafined austenite grains were heavily
deformed at different temperature, and the uniform microstructures with some 0.1~0.3μm equiaxed
ferrites were obtained.
Microstructure and Properties of Pipeline Steel with Acicular Ferrite
Authors: Zheng Lei , Gao Shan
Published: March 2009

The X70 grade and X80 grade pipeline steel strip with acicular ferrite microstructure
have been researched and developed. The properties of the steel with acicular ferrite were studied
by using tensile test, Charpy impact test, CTOD test and DWTT test, and compared to that of the
steel with ferrite and pearlite. The microstructure of acicular ferrite was analyzed by using optical
metallographic microscopy, scanning electron microscopy and transmission electron microscopy. It
shows that the acicular ferrite pipeline steel has high strength, high toughness, low ductile-brittle
transition temperature and high fracture-arrest toughness, the excellent properties are benefit from the
uniform microstructure, clean steel, and the low carbon acicular ferrite in which consist of interaction
of very fine precipitated particles and high-density dislocation.
Ultra Rapid Softening of High Strength Structural Steels by Thermomechanical Treatment
Authors: Adachi Yoshitaka , Tsuzaki Kaneaki
Published: March 2009

This study aims to shorten the softening treatment period as possible in high strength structural steels. The steel
used is SCM440 steel. As an initial microstructure, martensite, bainite, pearlite and complicated microstructure
consisting of ultrafine polygonal, martensite and equiaxed cementite were extensively examined to understand
their softening process on aging at 973K. These initial microstructures were prepared by heat or
thermomechanical treatment. Their initial Vickers hardness (Hv(10kgf)) were 634, 281, 219 and 238,
respectively. It is noteworthy that within five minutes on aging hardness of the complicated microstructure
reached lower than Hv200, while it took more than several hours for other initial microstructures. A
quantitative evaluation of microstructures appears to help in understanding the mechanism of the softening
kinetics.
Static Strain Aging in Cold Rolled Metastable Austenitic Stainless Steels
Authors: Antoine P. , Soenen B. , Akdut Nuri
Published: March 2009

Transformation of austenite to martensite during cold rolling operations is widely used to
strengthen metastable austenitic stainless steel grades. Static strain aging (SSA) phenomena at low
temperature, typically between 200°C and 400°C, can be used for additional increase in yield
strength due to the presence of α’-martensite in the cold rolled metastable austenitic stainless steels.
Indeed, SSA in austenitic stainless steel affects mainly in α’-martensite. The SSA response of three
industrial stainless steel grades was investigated in order to understand the aspects of the aging
phenomena at low temperature in metastable austenitic stainless steels. In this study, the
optimization of, both, deformation and time-temperature parameters of the static aging treatment
permitted an increase in yield strength up to 300 MPa while maintaining an acceptable total
elongation in a commercial 301LN steel grade. Deformed metastable austenitic steels containing the
“body-centered” α’-martensite are strengthened by the diffusion of interstitial solute atoms during
aging at low temperature. Therefore, the carbon redistribution during aging at low temperature is
explained in terms of the microstructural changes in austenite and martensite.
Nanoscale Behaviour of Certain Materials/Surfaces
Authors: Datta Psantu K. , Klusek Zbigniew , Du Hai Liang , Burnell-Gray Jim. S.
Published: March 2009

Nanoscale studies of four important phenomena – in-situ development of high
temperature (HT) wear resistant nanostructured surface glaze, the initial stages of oxidation of TiAl
intermetallics, the high temperature degradation of DLC coatings and the property change promoted
by nano-patterning of a TiO2 surface are described.
Calcium Phosphate Films Coated on Titanium by RF Magnetron Sputtering for Medical Applications
Authors: Narushima Takayuki , Ueda Kyosuke , Goto Takashi , Katsube Tomoyuki , Kawamura Hiroshi , Ouchi Chiaki , Iguchi Yasutaka
Published: March 2009

Calcium phosphate films were coated on commercially pure titanium substrates by
radiofrequency magnetron sputtering using β-tricalcium phosphate targets. The films consisted of
amorphous calcium phosphate and oxyapatite phases. Immersion tests of the films were carried out in
Hanks’ solution and PBS(-), and apatite formation and calcium ion elution from the films were
investigated. The titanium cylinders coated with calcium phosphate films were implanted into the
mandibles of beagle dogs. These results suggest that coating with calcium phosphate improves the
biocompatibility of titanium implants with bone tissue.